Methods and Apparatus for the Treatment / Prevention of Refractive Error and Image Processing and Display - Patent application

Abstract

Methods and devices are disclosed that are useful in the field of image processing and display, and in the field of ophthalmology, and in some specific embodiments, for the non-invasive treatment and / or prevention of refractive errors.

Description

[Technical field]

[0001] [Related Applications] This application benefits from U.S. provisional patent application US63 / 293,909, filed December 27, 2021, and U.S. utility patent application US17 / 863,715, filed July 13, 2022, both of which are incorporated by reference as if fully set forth herein.

[0002] [Field and Background of the Invention] The present invention relates in some embodiments to the field of image processing and display, and more particularly, but not exclusively, to methods and apparatus useful for image processing and display of images of a human subject.The present invention relates in some embodiments to the field of ophthalmology, and more particularly, but not exclusively, to methods and apparatus useful for the non-invasive treatment and / or prevention of refractive errors in a human subject.

[0003] The eyeball of a human baby born at full term is approximately 1.8 cm long (from the cornea to the back of the eye). The eye continues to grow throughout childhood, reaching a length of approximately 2.5 cm in adulthood, during which time ideal emmetropia occurs.

[0004] Emmetropia is when the optical power of the eye and the axial length of the eye are matched such that distant images are focused on the photoreceptor layer in the absence of accommodation.

[0005] Emmetropization is the process of achieving emmetropia and involves a reduction of the refractive error present at birth. The refractive state of newborns varies from person to person; most newborn eyes are hyperopic and usually become emmetropic over time. The curvature of the ocular components, especially the lens and cornea, continues to change and eye growth occurs beyond the time when initial emmetropia is achieved. Thus, the eyes also need to maintain emmetropia. It is indisputable that emmetropization is in part achieved actively by visual feedback. However, little is known about the process by which emmetropia is maintained.

[0006] In some cases, the eye continues to undergo physical changes even after reaching emmetropia, eventually resulting in myopia, which is usually caused by an increase in the axial length of the eyeball and / or the curvature of the cornea, causing light from distant objects to be focused in front of the retina, resulting in reduced visual acuity.

[0007] Myopia, also known as nearsightedness, is the most common eye disease in the world. The prevalence of myopia is approximately 30-40% of adults in the Western world and over 80% in adolescents in Asia, especially China. Some children who develop myopia continue to develop myopia throughout their school years, including high school. Long-term risks associated with myopia progression include cataracts, glaucoma, macular degeneration, and retinal detachment.

[0008] The applicant's US Pat. No. 1,064,882 describes an apparatus for screening, monitoring and / or assessing visual impairment.

[0009] US 2022 / 0057651 describes a technique for driving emmetropization of an eye, including receiving image data corresponding to a color image, providing simulated longitudinal chromatic aberration (LCA) in at least a portion of the color image by blurring a first color channel of the image data to a greater extent than a second color channel of the image data, and providing emmetropization therapy to the eye by displaying the color image with the simulated LCA.

[0010] Additional background art useful in understanding aspects of the present invention includes US2019 / 0377191, US2019 / 0094552, and US2018 / 0096461.

[0011] [Summary of the invention] Some embodiments relate to the field of image processing and display, and more particularly, but not exclusively, to methods and apparatus useful for image processing and display of images of a human subject. Some embodiments of the invention herein relate to methods and apparatus useful in the field of ophthalmology, and in some specific embodiments, useful for non-invasive treatment and / or prevention of refractive errors, particularly myopia, and / or reducing the rate of growth of the eye. Some embodiments of the teachings herein are useful for one or more of preventing the onset of refractive errors, arresting the progression of existing refractive errors, and reducing the severity of existing refractive errors, particularly myopia, hyperopia, and astigmatism. In some embodiments, the methods and apparatus according to the teachings herein comprise generating a display image from a base image and displaying the display image to a human subject. The display image is comprised of at least two distinct portions, a central vision portion and a non-central vision portion, the image quality of the non-central vision portion being lower than the image quality of the central vision portion.

[0012] According to aspects of some embodiments of the teachings herein, there is provided a method useful for treating existing refractive errors and / or preventing the development of refractive errors in a human subject, the method comprising: a. determining a gaze direction of a first eye of a subject viewing an image on a display screen and providing the determined gaze direction to a computer processor; b. Following 'a', generating, by a computer processor, a display image from the received digital-based image for display on a display screen to the first eye based on the determined gaze direction of the first eye, comprising: i. a central vision portion of the displayed image corresponding to a portion of the field of view of the first eye that includes the determined gaze direction; or is altered such that visual characteristics of the central vision portion of the displayed image are altered compared to corresponding visual characteristics of the central vision portion of the displayed image, the alteration improving image quality of the central vision portion compared to corresponding portions of the displayed image; ii. A non-central portion of the displayed image that is different from the central portion: either unchanged compared to corresponding portions in the base image; or modified such that visual characteristics of the non-foveal portions of the displayed image change compared to corresponding visual characteristics of corresponding portions in the base image; generating a display image having a lower image quality for non-central portions of the display image than for central portions of the display image; c. displaying the generated display image on a display screen such that a first eye of the subject views the display image on the display screen.

[0013] In accordance with aspects of some embodiments of the teachings herein, there is provided a method for image processing and display, the method comprising: a. determining a gaze direction of a first eye of a person viewing an image on a display screen and providing the determined gaze direction to a computer processor; b. Following 'a', generating, by a computer processor, a display image from the received digital-based image for display on a display screen to the first eye based on the determined gaze direction of the first eye, comprising: i. a central vision portion of the displayed image corresponding to a portion of the field of view of the first eye that includes the determined gaze direction; or is altered such that visual characteristics of the central vision portion of the displayed image are altered compared to corresponding visual characteristics of the central vision portion of the displayed image, the alteration improving image quality of the central vision portion compared to corresponding portions of the displayed image; ii. a non-central portion of the displayed image that is different from the central portion; either unchanged compared to corresponding portions in the base image; or modified such that visual characteristics of the non-foveal portions of the displayed image change compared to corresponding visual characteristics of corresponding portions in the base image; generating a display image having a lower image quality for non-central portions of the display image than for central portions of the display image; and c. displaying the generated display image on a display screen such that a first eye of the person views the display image on the display screen.

[0014] In some embodiments, either method further includes displaying the generated display image on a display screen (e.g., when the method is performed using VR goggles) such that a second eye of the subject views the display image on the display screen, i.e., either the same display screen or a different display screen. In some such embodiments, the display image is displayed at the same location on the same display screen for simultaneous viewing by both eyes, i.e., both eyes view the same image displayed on the same display screen.

[0015] Alternatively, in some embodiments, either method further comprises, in conjunction with 'a' and 'b': d. determining a gaze direction of a second eye of the subject (person) viewing the second eye display screen and providing the determined gaze direction to a computer processor; e. Following 'c', generating, by the computer processor, a second display image from the received digital-based image for display on a second eye display screen to the second eye based on the determined gaze direction of the second eye, comprising: i. a central viewing portion of the second displayed image corresponding to a portion of the field of view of the second eye that includes the determined gaze direction: or is altered such that visual characteristics of the central vision portion of the second display image are altered compared to corresponding visual characteristics of the central vision portion of the second display image, the alteration improving image quality of the central vision portion compared to corresponding portions of the second display image; ii. a non-central portion of the second display image that is different from the central portion; either unchanged compared to corresponding portions in the base image; or modified such that visual characteristics of the non-foveal portions of the second display image change compared to corresponding visual characteristics of corresponding portions in the base image; generating a second display image having a lower image quality for non-central vision portions than for central vision portions of the second display image; f. Displaying the generated second display image on a second eye display screen such that the second eye of the subject (person) sees the second display image on the second eye display screen.

[0016] In such an embodiment, the second eye does not see the display image and the first eye does not see the second display image. In some such embodiments, the second eye's display screen and the display screen are two different physical components (e.g., some VR glasses). In some such embodiments, the second eye's display screen and the display screen are the same physical screen, but the second display image and the display image are displayed in different positions on the screen (e.g., some VR glasses with a left eye / right eye partition), in the same place on the screen but at different times (e.g., shutter glasses), or in the same place on the same screen at the same time (e.g., using anaglyph or autostereoscopic methods).

[0017] In some embodiments, a centrally viewed portion of the displayed image corresponds to a first eye's field of view centered about the determined gaze direction of the first eye. Similarly, in some embodiments, where applicable, a centrally viewed portion of the second displayed image corresponds to a second eye's field of view centered about the determined gaze direction of the first eye.

[0018] In some embodiments, the central viewing portion of the displayed image is circular in shape. Similarly, where applicable, in some embodiments, the central viewing portion of the second displayed image is circular in shape.

[0019] In some embodiments, the size of the central viewing portion of the display image corresponds to a first eye field of view of at least about 1° to about 20° (in particularly preferred embodiments, about 2° to about 8°) including the determined gaze direction of the first eye. In some embodiments, the size of the central viewing portion of the display image corresponds to a first eye field of view of at least about 1° to about 4°, or even at least about 1° to about 3° including the determined gaze direction of the first eye. Similarly, where applicable, in some embodiments, the size of the central viewing portion of the second display image corresponds to a second eye field of view of at least about 1° to about 20° (in particularly preferred embodiments, about 2° to about 8°) including the determined gaze direction of the second eye. Similarly, in some embodiments, the size of the central viewing portion of the second display image corresponds to a second eye field of view of at least about 1° to about 4°, or even at least about 1° to about 3° including the determined gaze direction of the second eye.

[0020] In some embodiments, the centrally viewed portion of the display image is not altered compared to the corresponding portion in the base image. Similarly, in some embodiments, the centrally viewed portion of the second display image is not altered compared to the corresponding portion in the base image.

[0021] Alternatively, in some embodiments, a centrally viewed portion of the display image is modified such that visual characteristics of the centrally viewed portion of the display image change compared to corresponding visual characteristics of the corresponding portion in the base image, which modification changes the image quality of the centrally viewed portion relative to the corresponding portion in the base image. In some embodiments, such modification improves the image quality of the centrally viewed portion of the display image compared to the corresponding portion in the base image. Similarly, in some embodiments, a centrally viewed portion of the second display image is modified such that visual characteristics of the centrally viewed portion of the display image change compared to corresponding visual characteristics of the corresponding portion in the base image, which modification changes the image quality of the centrally viewed portion relative to the corresponding portion in the base image. In some embodiments, such modification improves the image quality of the centrally viewed portion of the second display image compared to the corresponding portion in the base image.

[0022] The relative orientation of the central and non-central viewing portions in the display image and / or the second display image may be any suitable relative orientation. In some embodiments, the non-central viewing portion is contiguous with the central viewing portion. In some embodiments, the non-central viewing portion of the display image at least partially surrounds the central viewing portion. In some embodiments, the non-central viewing portion of the display image completely surrounds the central viewing portion.

[0023] In some embodiments, a radial dimension of the non-central portion of the displayed image corresponds to a first eye's field of view of at least about 2°. Similarly, where applicable, in some embodiments, a radial dimension of the non-central portion of the second displayed image corresponds to a second eye's field of view of at least about 2°.

[0024] Further, in some embodiments, the radial dimension of the non-central viewing portion of the display image corresponds to a first eye's field of view that is at least equal to a minimum value and is equal to or less than a maximum value, with the minimum value being about 2° and the maximum value being about 30°. In some such embodiments, the non-central viewing portion of the display image has a ring shape and has an inner dimension (a typical dimension contiguous with the central viewing portion of the display image) and an outer dimension, with the difference between the outer dimension and the inner dimension being between a minimum value and a maximum value. In some embodiments, the minimum value is about 3°, about 4°, or even about 5°. In some embodiments, the maximum value is about 25°, about 20°, or even about 15°. Similarly, in some embodiments, the radial dimension of the non-central viewing portion of the second display image corresponds to a second eye's field of view that is at least equal to a minimum value and is equal to or less than a maximum value, with the minimum value being about 2° and the maximum value being about 30°. In some such embodiments, the non-central viewing portion of the second display image has a ring shape and has an inner dimension (a typical dimension contiguous with the central viewing portion of the second display image) and an outer dimension, with the difference between the outer dimension and the inner dimension being between a minimum value and a maximum value. In some embodiments, the minimum value is about 3°, about 4°, or even about 5°. In some embodiments, the maximum value is about 25°, about 20°, or even about 15°. An advantage of such embodiments is that the computational effort to generate such relatively small non-central portions may be relatively modest, even when using relatively complex operators.

[0025] In some embodiments, the non-central viewing portion is the balance of the displayed image that is not the central viewing portion, i.e., about 100% of the area of ​​the displayed image that is not the central viewing portion is the non-central viewing portion. Similarly, if applicable, in some embodiments, the non-central viewing portion is the balance of the second displayed image that is not the central viewing portion, i.e., about 100% of the area of ​​the second displayed image that is not the central viewing portion is the non-central viewing portion.

[0026] In some embodiments, the second portion of the image and / or the second image is neither a central nor a non-central portion. In preferred such embodiments, the third portion is not modified or processed and, when displayed on a display screen, appears the same as the corresponding portion in the base image when displayed. An advantage of such embodiments is that the computational effort to generate the relatively small non-central portions may be relatively modest, even when using relatively complex operators, allowing, in some embodiments, the use of higher frame rates and / or more complex operators. A further advantage of some such embodiments is that the smaller non-central portions are less intrusive to the viewer.

[0027] Thus, in some embodiments, the non-central vision portion is at least 1% to about 80% of the area of ​​the non-central vision portion of the displayed image. In some such embodiments, the non-central vision portion is at least about 5%, at least about 10%, at least about 20%, or even at least about 30% of the area of ​​the non-central vision portion of the displayed image. Additionally or alternatively, in some embodiments, the non-central vision portion is at most about 70%, at most about 60%, or even at most about 50% of the area of ​​the non-central vision portion of the displayed image. In one particularly preferred embodiment, the non-central vision portion is at least 30% to about 50% of the area of ​​the non-central vision portion of the displayed image. In another particularly preferred embodiment, the non-central vision portion is at least 5% to about 50%, at most about 40%, or even at most about 30% of the area of ​​the non-central vision portion of the displayed image.

[0028] Similarly, where applicable, in some embodiments, the non-central viewing portion is at least 1% to about 80% of the area of ​​the second display image that is not the central viewing portion. In some such embodiments, the non-central viewing portion is at least about 5%, at least about 10%, at least about 20%, or even at least about 30% of the area of ​​the second display image that is not the central viewing portion. Additionally or alternatively, in some embodiments, the non-central viewing portion is about 70% or less, about 60% or less, or even about 50% or less of the area of ​​the second display image that is not the central viewing portion. In one particularly preferred embodiment, the non-central viewing portion is at least 30% to about 50% of the area of ​​the second display image that is not the central viewing portion. In another particularly preferred embodiment, the non-central viewing portion is at least 5% or more and about 50% or less, about 40% or less, or even about 30% or less of the area of ​​the second display image that is not the central viewing portion.

[0029] In some embodiments, non-central portions of the display image are not altered compared to corresponding portions in the base image. Similarly, where applicable, in some embodiments, non-central portions of the second display image are not altered compared to corresponding portions in the base image.

[0030] In some preferred embodiments, the non-central portions of the display image are modified such that visual characteristics of the non-central portions of the display image change compared to corresponding visual characteristics of the corresponding portions in the base image, which changes the image quality of the non-central portions of the display image relative to the corresponding portions in the base image. In some embodiments, such modifications improve the image quality of the non-central portions of the display image compared to the corresponding portions in the base image. Alternatively, in some preferred embodiments, such modifications degrade the image quality of the non-central portions of the display image compared to the corresponding portions in the base image. Similarly, where applicable, in some preferred embodiments, the non-central portions of the second display image are modified such that visual characteristics of the non-central portions of the second display image change compared to corresponding visual characteristics of the corresponding portions in the base image, which changes the image quality of the non-central portions of the second display image compared to the corresponding portions in the base image. In some embodiments, such modifications improve the image quality of the non-central portions of the second display image compared to the corresponding portions in the base image. Alternatively, in some preferred embodiments, such modifications degrade the image quality of the non-central portions of the second display image compared to the corresponding portions in the base image.

[0031] In some embodiments, the alteration that degrades the image quality of the non-central portions of the display image and / or the second display image compared to the corresponding portions in the base image includes at least one member selected from the group consisting of: reducing resolution; blurring; reducing contrast; reducing / increasing brightness; reducing color intensity; reducing or changing color palette, and combinations thereof. In some embodiments where the base image is a color image consisting of a red sub-image, a green sub-image, and a blue sub-image, a reduced or changed color palette means reducing the number of available values ​​that pixels located in the non-central portions of one, two, or all three sub-images may have in the corresponding display image. For example, if the base image consists of three sub-images, each pixel having a value between 0 and 255, in some such embodiments, two of the three sub-images are unchanged, but for one of the sub-images (e.g., the blue sub-image), the number of available values ​​that pixels located in the non-central portions may adopt is reduced to 8 (values ​​between 0 and 7).

[0032] In some embodiments, the alteration that degrades the image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes a reduction in resolution.

[0033] In some embodiments, the alteration that degrades image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes blurring.

[0034] In some embodiments, the alteration that degrades image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes a reduction in contrast.

[0035] In some embodiments, the alteration that degrades the image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes a reduction / increase in luminance.

[0036] In some embodiments, the alteration that degrades image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes a reduction in color intensity.

[0037] In some embodiments, the alteration that degrades the image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes a reduction or change in the color palette.

[0038] In some embodiments, the modification that degrades image quality of the non-central portion compared to the corresponding portion in the base image includes changing a value of a pixel of the non-central portion compared to a value of a corresponding pixel in the corresponding portion in the base image, wherein the magnitude and / or type of change to the pixel value is independent of the value of any neighboring pixels in the base image.

[0039] In some embodiments, generating the display image includes generating the display image as an image data structure (e.g., an image data file), and displaying the generated display image is subsequently displaying the generated image data structure on a display screen. Similarly, where applicable, in some embodiments, generating the second display image includes generating the second display image as an image data structure, and displaying the generated second display image is subsequently displaying the generated image data structure on a display screen. In preferred such embodiments, the image data structure is stored (e.g., in a computer memory such as a RAM or ROM) during or after generation, and subsequently displayed. In some embodiments, the image data structure is generated by executing a graphical operator on a base image data structure.

[0040] In some embodiments, the display image and / or the second display image are generated with the aid of a mask image generated based on the determined gaze direction, the mask image being independent of the base image. The mask image includes a non-degraded central viewing portion that includes the determined gaze direction, and the non-degraded central viewing portion is typically "transparent" such that when the mask image is combined and / or displayed with the base image, the portion of the resulting display image (or the second display image) that corresponds to the central viewing portion appears unchanged on the display screen. The mask image also includes a degraded non-central viewing portion such that when the mask image is combined and / or displayed with the base image, the portion of the resulting display image (or the second display image) that corresponds to the non-central viewing portion appears degraded on the display screen. The computational power required to implement some such embodiments is typically modest, allowing implementation at higher frame rates. Moreover, since the mask image is generated without the need to query pixels of the base image, the implementation of such embodiments is relatively simple and easy. In some embodiments in which a second display image is generated, the second display image is generated as described herein with the aid of the same mask image used to generate the display image. Alternatively, in some embodiments where a second display image is generated, the second display image is generated with the aid of a mask image that is different from the mask image used to generate the display image.

[0041] In some embodiments, generating the display image includes: generating a mask image independent of the base image, the mask image having a non-degraded central vision portion and a degraded non-central vision portion; combining the mask image with the base image to thereby generate the display image as an image data structure, and displaying the generated display image is then displaying the generated image data structure on a display screen. Similarly, where applicable, in some embodiments, generating a second display image includes: generating a mask image independent of the base image, the mask image having a non-degraded central vision portion and a degraded non-central vision portion; combining the mask image with the base image to thereby generate the second display image as an image data structure, and displaying the generated second display image is then displaying the generated image data structure on a display screen. In preferred such embodiments, the image data structure is stored (e.g., in a computer memory such as a RAM or ROM) during or after generation and then displayed.

[0042] Alternatively, in some embodiments, generating the display image includes: generating a mask image that is independent of the base image, the mask image including a non-degraded central vision portion and a degraded non-central vision portion; and then displaying the generated mask image together with the base image on a display screen such that the display image is both generated and displayed simultaneously. Similarly, where applicable, in some embodiments, generating the second display image includes: generating a mask image that is independent of the base image, the mask image including a non-degraded central vision portion and a degraded non-central vision portion; and then displaying the generated mask image together with the base image on a display screen such that the second display image is both generated and displayed simultaneously.

[0043] In some embodiments, the method further includes: providing the computer processor with a distance from the display screen to the cornea of ​​the first eye prior to generating the display image 'b'; and generating the display image is also based on the provided distance from the display screen to the cornea of ​​the first eye. Similarly, where applicable, in some embodiments, the method further includes: providing the computer processor with a distance from the display screen to the cornea of ​​the second eye prior to generating the second display image 'e'; and generating the second display image is also based on the provided distance from the display screen to the cornea of ​​the second eye. In some such embodiments, providing the computer processor with a distance from the display screen to the cornea of ​​the first eye and / or the second eye includes inputting one or more distance values ​​as parameters to the computer processor. Alternatively, in some such embodiments, providing the computer processor with a distance from the display screen to the cornea of ​​the first eye includes determining a distance between the display screen and the cornea of ​​the first eye of the subject, the determined distance being used to generate the display image, and in some embodiments also used to generate the second display image. Similarly, if applicable, in some embodiments providing the distance from the display screen to the cornea of ​​the second eye to the computer processor includes determining a distance between the display screen and the cornea of ​​the subject's second eye, the determined distance being used to generate the second display image.

[0044] In a particularly preferred embodiment, a method useful for treating existing refractive errors and / or preventing the development of refractive errors in a human subject is provided, the method comprising: a. determining a gaze direction of a first eye of a subject viewing an image on a display screen and providing the determined gaze direction to a computer processor; b. Following 'a', generating, by a computer processor, a display image for display on a display screen to the first eye from the received digital-based image based on the determined gaze direction of the first eye, comprising: i. a central vision portion of the displayed image corresponding to a portion of the field of view of the first eye that includes the determined gaze direction is not altered compared to a corresponding portion in the base image; ii. non-central portions of the display image that are distinct from the central portion are modified such that visual characteristics of the non-central portions of the display image change compared to corresponding visual characteristics of corresponding portions in the base image, the modification degrading image quality of the non-central portions compared to corresponding portions in the base image; c. displaying the generated display image on a display screen such that a first eye and a second eye of the subject view the display image on the display screen simultaneously and at the same location on the display screen; a size of a central portion of the displayed image corresponding to a field of view of the first eye of at least about 1° and no more than about 20° that includes the determined gaze direction of the first eye; the non-central vision portion completely surrounds the central vision portion and is at least 1% (in some alternative preferred embodiments, at least about 30%) of the area of ​​the displayed image that is not the central vision portion; The modification that degrades the image quality of the non-central vision portion compared to the corresponding portion in the base image includes at least one modification selected from the group consisting of: reducing the resolution; blurring; reducing the contrast; reducing / increasing the brightness; reducing the color intensity; reducing or changing the color palette, and combinations thereof. In some preferred embodiments, the modification that degrades the image quality of the non-central vision portion compared to the corresponding portion in the base image includes at least one modification selected from the group consisting of: reducing the contrast; reducing / increasing the brightness; reducing the color intensity; reducing or changing the color palette, and combinations thereof.

[0045] In a particularly preferred embodiment, a method useful for treating existing refractive errors and / or preventing the development of refractive errors in a human subject is provided, the method comprising: a. determining a gaze direction of a first eye of a subject viewing an image on a display screen and providing the determined gaze direction to a computer processor; b. Following 'a', generating, by a computer processor, a display image for display on a display screen to the first eye from the received digital-based image based on the determined gaze direction of the first eye, comprising: i. a central vision portion of the displayed image corresponding to a portion of the field of view of the first eye that includes the determined gaze direction is not altered compared to a corresponding portion in the base image; ii. non-central portions of the display image that are distinct from the central portion are modified such that visual characteristics of the non-central portions of the display image change compared to corresponding visual characteristics of corresponding portions in the base image, the modification degrading image quality of the non-central portions compared to corresponding portions in the base image; c. displaying the generated display image on a display screen such that a first eye and a second eye of the subject view the display image on the display screen simultaneously and at the same location on the display screen; a size of a central portion of the displayed image corresponding to a field of view of the first eye of at least about 1° and no more than about 20° that includes the determined gaze direction of the first eye; the non-central vision portion completely surrounds the central vision portion and is at least about 1% (in some alternative preferred embodiments, at least about 30%) of the area of ​​the displayed image that is not the central vision portion; The modification that degrades the image quality of the non-central portion compared to the corresponding portion in the base image includes changing the value of a pixel of the non-central portion compared to the value of a corresponding pixel of the corresponding portion in the base image, wherein the magnitude and / or type of change to the pixel value is independent of the value of any adjacent pixels in the base image.

[0046] In accordance with aspects of some embodiments of the teachings herein, there is also provided, in some embodiments, an apparatus for image processing and display useful for treating existing refractive errors and / or preventing the development of refractive errors in a human subject, the apparatus comprising: a computer processor operatively associated with the display screen and the eye tracker, the eye tracker configured to determine a gaze direction of a first eye of a person viewing an image on the display screen and provide the determined gaze direction to the computer processor; Computer processors: configured to generate a display image from the received digitally based image based on a gaze direction of the first eye received from the eye tracker, wherein; i. The central portion of the displayed image corresponding to the portion of the first eye's field of view that includes the determined gaze direction is: or is altered such that visual characteristics of the central vision portion of the displayed image are altered compared to corresponding visual characteristics of the central vision portion of the displayed image, the alteration improving image quality of the central vision portion compared to corresponding portions of the displayed image; ii. Non-central portions of the displayed image that are different from the central portion are: either unchanged compared to corresponding portions in the base image; or altered such that the visual characteristics of the non-foveal portions of the displayed image change compared to corresponding visual characteristics of the corresponding portions in the base image; resulting in image quality of non-central portions of the displayed image being lower than image quality of central portions of the displayed image; The generated display image is displayed on a display screen such that a first eye of a person would view the display image on the display screen.

[0047] In some embodiments, the display screen is configured to allow the subject's second eye to view the generated display image on the display screen (i.e., on a different display screen (e.g., using VR glasses having a different display screen for each eye) or on the same display screen). In some such embodiments, the generated display image is displayed at the same location on the display screen for simultaneous viewing by both eyes.

[0048] In some embodiments, the apparatus comprises: further comprising an eye tracker configured to determine a gaze direction of a second eye of a person viewing the display screen and provide the determined gaze direction of the second eye to the computer processor; Computer processors: configured to generate a second display image from the received digital base image and based on the gaze direction of the second eye received from the eye tracker: i. The central viewing portion of the second displayed image corresponding to a portion of the field of view of the second eye that includes the determined gaze direction is: or is altered such that visual characteristics of the central vision portion of the second display image are altered compared to corresponding visual characteristics of the central vision portion of the second display image, the alteration improving image quality of the central vision portion compared to corresponding portions of the second display image; ii. A non-central portion of the second displayed image that is different from the central portion is: either unchanged compared to a corresponding portion in the base image; or altered such that a visual characteristic of the non-foveal portion of the second display image is altered compared to a corresponding visual characteristic of the corresponding portion in the base image; generating a lower image quality for the non-central viewing portion of the second displayed image than for the central viewing portion of the second displayed image; The generated second display image is displayed on a display screen operatively associated with the computer processor such that a second eye of the person views the second display image on the display screen.

[0049] In such embodiments, the device is configured such that the second eye does not see the display image and the first eye does not see the second display image. In some such embodiments, the second eye's display screen and the display screen are two different physical components (e.g., some VR glasses). In some such embodiments, the second eye's display screen and the display screen are the same physical screen, but the second display image and the display image are displayed in different positions on the screen (e.g., some VR glasses with a left eye / right eye partition), in the same place on the screen but at different times (e.g., shutter glasses), or in the same place on the same screen at the same time (e.g., using anaglyph or autostereoscopic methods).

[0050] In some embodiments, the same eye tracker is used to determine the gaze direction of both eyes. In some embodiments, the device includes two different eye trackers, a first eye tracker for determining the gaze direction of a first eye, and a second eye tracker for determining the gaze direction of a second eye.

[0051] In some embodiments, the central viewing portion of the displayed image corresponds to a first eye's field of view centered on the determined gaze direction of the first eye. Similarly, in some embodiments, where applicable, the central viewing portion of the second displayed image corresponds to a second eye's field of view centered on the determined gaze direction of the second eye.

[0052] In some embodiments, the central viewing portion of the displayed image is circular in shape. Similarly, where applicable, in some embodiments, the central viewing portion of the second displayed image is circular in shape.

[0053] In some embodiments, the computer processor is configured to have a size of the central viewing portion of the display image corresponding to a first eye field of view of at least about 1° to about 20° including the determined gaze direction of the first eye. In preferred embodiments, the computer processor is configured to have a size of the central viewing portion of the display image corresponding to a first eye field of view of at least about 2° to about 8° including the determined gaze direction of the first eye. Similarly, where applicable, in some embodiments, the computer processor is configured to have a size of the central viewing portion of the second display image corresponding to a second eye field of view of at least about 1° to about 20° including the determined gaze direction of the second eye. In preferred embodiments, the computer processor is configured to have a size of the central viewing portion of the second display image corresponding to a second eye field of view of at least about 2° to about 8° including the determined gaze direction of the second eye.

[0054] In some embodiments, the computer processor is configured such that centrally viewed portions of the generated display image are not altered compared to corresponding portions of the base image.

[0055] In some embodiments, the computer processor is configured to modify the base image such that visual characteristics of a central vision portion of the generated display image are changed compared to corresponding visual characteristics of a corresponding portion in the base image, the modification improving image quality of the central vision portion compared to the corresponding portion in the base image.

[0056] In some embodiments, the computer processor is configured such that the non-central viewing portion of the generated display image and / or the second display image is contiguous with the central viewing portion. Additionally or alternatively, in some embodiments, the computer processor is configured such that the non-central viewing portion of the generated display image and / or the second display image at least partially surrounds the central viewing portion. Additionally or alternatively, in some embodiments, the computer processor is configured such that the non-central viewing portion of the generated display image or the second display image completely surrounds the central viewing portion.

[0057] In some embodiments, the computer processor is configured such that a radial dimension of the non-central portion of the generated display image and / or the second display image corresponds to a field of view of each eye of at least about 2°.

[0058] Further, in some embodiments, the computer processor is configured such that the radial dimension of the non-central portion of the display image corresponds to a field of view of the respective eye that is at least equal to a minimum value and equal to or less than a maximum value, the minimum value being about 2° and the maximum value being about 30°. In some such embodiments, the computer processor is configured such that the non-central portion of the display image has a ring shape, has an inner dimension (a typical dimension contiguous with the central portion of the display image) and an outer dimension, and the difference between the outer dimension and the inner dimension is between a minimum value and a maximum value. In some embodiments, the minimum value is about 3°, about 4°, or even about 5°. In some embodiments, the maximum value is about 25°, about 20°, or even about 15°. Similarly, in some embodiments, the computer processor is configured such that the radial dimension of the non-central portion of the second display image corresponds to a field of view of the second eye that is at least equal to a minimum value and equal to or less than a maximum value, the minimum value being about 2° and the maximum value being about 30°. In some such embodiments, the non-central viewing portion of the second display image has a ring shape, an inner dimension (a typical dimension contiguous with the central viewing portion of the second display image) and an outer dimension, and the difference between the outer dimension and the inner dimension is between a minimum and a maximum value. In some embodiments, the minimum value is about 3°, about 4°, or even about 5°. In some embodiments, the maximum value is about 25°, about 20°, or even about 15°. An advantage of such embodiments is that the computational effort to generate such relatively small non-central viewing portions can be relatively modest, even when using relatively complex operators.

[0059] In some embodiments, the computer processor is configured such that the non-central portions are the balance of the displayed image that are not centrally visible portions, i.e., approximately 100% of the area of ​​the displayed image that are not centrally visible portions are non-centrally visible portions. Similarly, where applicable, in some embodiments, the computer processor is configured such that the non-central portions are the balance of the second displayed image that are not centrally visible portions, i.e., approximately 100% of the area of ​​the second displayed image that are not centrally visible portions are non-centrally visible portions.

[0060] In some embodiments, the computer processor is configured such that the third portion of the image and / or the second image is neither a central nor a non-central portion. In preferred such embodiments, the computer processor is configured such that the third portion is not modified or processed and when displayed on a display screen appears the same as the corresponding portion in the base image when displayed. An advantage of such embodiments is that the computational effort to generate the relatively small non-central portions can be relatively modest, even when using relatively complex operators, allowing in some embodiments the use of higher frame rates and / or more complex operators. A further advantage of some such embodiments is that the smaller non-central portions are less intrusive to a viewer.

[0061] Thus, in some embodiments, the computer processor is configured such that the non-central portion is at least 1% to about 80% of the area of ​​the non-central portion of the displayed image. In some such embodiments, the computer processor is configured such that the non-central portion is at least about 5%, at least about 10%, at least about 20%, or even at least about 30% of the area of ​​the non-central portion of the displayed image. Additionally or alternatively, in some embodiments, the non-central portion is at most about 70%, at most about 60%, or even at most about 50% of the area of ​​the non-central portion of the displayed image. In a particularly preferred embodiment, the non-central portion is at least 30% to about 50% of the area of ​​the non-central portion of the displayed image. In another particularly preferred embodiment, the non-central portion is at least 5% to about 50%, at most about 40%, or even at most about 30% of the area of ​​the non-central portion of the displayed image.

[0062] Similarly, where applicable, in some embodiments, the computer processor is configured such that the non-central viewing portion is at least 1% to about 80% of the area of ​​the non-central viewing second display image. In some such embodiments, the computer processor is configured such that the non-central viewing portion is at least about 5%, at least about 10%, at least about 20%, or even at least about 30% of the area of ​​the non-central viewing second display image. Additionally or alternatively, in some embodiments, the non-central viewing portion is about 70% or less, about 60% or less, or even about 50% or less of the area of ​​the non-central viewing second display image. In a particularly preferred embodiment, the non-central viewing portion is at least 30% to about 50% of the area of ​​the non-central viewing second display image. In another particularly preferred embodiment, the non-central viewing portion is at least 5% or more and about 50% or less, about 40% or less, or even about 30% or less of the area of ​​the non-central viewing second display image.

[0063] In some embodiments, the computer processor is configured such that non-central portions of the generated display image and / or the second display image are unaltered compared to corresponding portions in the corresponding base image.

[0064] In some embodiments, the computer processor is configured to modify the base image such that visual characteristics of non-central portions of the generated display image and / or the second display image are changed compared to corresponding visual characteristics of corresponding portions in the base image, which modification changes the image quality of the non-central portions compared to corresponding portions in the base image.

[0065] Preferably, in some embodiments, the computer processor is further configured to modify the base image such that visual characteristics of non-central portions of the generated display image and / or the second display image are changed compared to corresponding visual characteristics of corresponding portions in the base image, which modification degrades image quality of the non-central portions compared to corresponding portions in the base image.

[0066] In some embodiments, the alteration that degrades the image quality of the non-central viewing portion of the display image and / or the second display image compared to the corresponding portion in the base image includes at least one member selected from the group consisting of: reducing resolution; blurring; reducing contrast; reducing / increasing brightness; reducing color intensity; reducing or changing color palette, and combinations thereof. In some embodiments where the base image is a color image consisting of a red sub-image, a green sub-image, and a blue sub-image, a reduced or changed color palette means reducing the number of available values ​​that pixels located in the non-central viewing portion of one, two, or all three sub-images may have in the corresponding display image. For example, if the base image consists of three sub-images, each pixel having a value between 0 and 255, in some such embodiments, two of the three sub-images are unchanged, but for one of the sub-images (e.g., the blue sub-image), the number of available values ​​that pixels located in the non-central viewing portion may adopt is reduced to 8 (values ​​between 0 and 7).

[0067] In some embodiments, the alteration that degrades the image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes a reduction in resolution.

[0068] In some embodiments, the alteration that degrades image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes blurring.

[0069] In some embodiments, the alteration that degrades image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes a reduction in contrast.

[0070] In some embodiments, the alteration that degrades the image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes a reduction / increase in luminance.

[0071] In some embodiments, the alteration that degrades image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes a reduction in color intensity.

[0072] In some embodiments, the alteration that degrades the image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes a reduction or change in the color palette.

[0073] In some embodiments, the modification that degrades the image quality of the non-central portion relative to the corresponding portion in the base image includes changing the value of a pixel of the non-central portion compared to the value of a corresponding pixel in the corresponding portion in the base image, where the magnitude and / or type of change to the pixel value is independent of the values ​​of any neighboring pixels in the base image.

[0074] In some embodiments, the computer processor is configured such that generating the display image includes generating the display image as an image data structure (e.g., an image data file) and displaying the generated display image is displaying the generated image data structure on a display screen. Similarly, where applicable, in some embodiments, the computer processor is configured such that generating the second display image includes generating the second display image as an image data structure and displaying the generated second display image is thereafter displaying the generated image data structure on a display screen. In preferred such embodiments, the computer processor is configured to store the image data structure (e.g., in a computer memory such as a RAM or ROM) during or after generation and thereafter display the stored image data structure. In some embodiments, the computer processor is configured to generate the image data structure by executing a graphical operator on a base image data structure.

[0075] In some embodiments, the computer processor is configured to generate the display image and / or the second display image by first generating a mask image based on the determined gaze direction, where the mask image is independent of the base image. The generated mask image includes a non-degraded central vision portion that includes the determined gaze direction, and the non-degraded central vision portion is typically "transparent" such that when the mask image is combined with and / or displayed with the base image, the portion of the resulting display image (or the second display image) that corresponds to the central vision portion appears unchanged on the display screen. The generated mask image also includes a degraded non-central vision portion such that when the computer processor combines and / or displays the mask image with the base image, the portion of the resulting display image (or the second display image) that corresponds to the non-central vision portion appears degraded on the display screen. The computing power required to implement some such embodiments is typically modest, allowing implementation at higher frame rates. Furthermore, because the computer processor generates the mask image without querying pixels of the base image, implementing such embodiments is relatively simple and easy. In some embodiments in which a second display image is generated, the computer processor generates the second display image as described herein with the aid of the same mask image used to generate the display image. Alternatively, in some embodiments in which a second display image is generated, the computer processor generates the second display image with the aid of a mask image that is different from the mask image used to generate the display image.

[0076] In some embodiments, the computer processor is configured to generate a display image comprising: generating a mask image independent of a base image, the mask image having a non-degraded central vision portion and a degraded non-central vision portion; combining the mask image with the base image to thereby generate a display image as an image data structure, and displaying the generated display image is then displaying the generated image data structure on a display screen. Similarly, where applicable, in some embodiments, the computer processor is configured to generate a second display image comprising: generating a mask image independent of a base image, the mask image having a non-degraded central vision portion and a degraded non-central vision portion; combining the mask image with the base image to thereby generate a second display image as an image data structure, and displaying the generated second display image is then displaying the generated image data structure on a display screen. In preferred such embodiments, the computer processor is configured to store the image data structure (e.g., in a computer memory such as a RAM or ROM) during or after generation, and then display the stored image data structure.

[0077] Alternatively, in some embodiments, a computer processor configuration for generating a display image includes: generating a mask image independent of a base image, the mask image including a non-degraded central vision portion and a degraded non-central vision portion; and then displaying the generated mask image together with the base image on a display screen such that the display image is both generated and displayed simultaneously. Similarly, when applicable, in some embodiments, a computer processor configuration for generating a second display image includes: generating a mask image independent of a base image, the mask image including a non-degraded central vision portion and a degraded non-central vision portion; and then displaying the generated mask image together with the base image on a display screen such that the second display image is both generated and displayed simultaneously.

[0078] In some embodiments, the computer processor is further configured to generate the display image and / or the second display image based also on a distance from the provided display screen to the cornea of ​​the first eye. Similarly, in some embodiments, where applicable, the computer processor is further configured to generate the second display image based also on a distance from the provided display screen to the cornea of ​​the second eye.

[0079] In some embodiments, the distance from the display screen to the cornea of ​​the first eye and / or the distance from the display screen to the cornea of ​​the second eye is provided as a parameter, for example, the distance is an estimated distance based on the size of the screen and / or expected use.

[0080] In some embodiments, the device further includes a component for determining a distance from the display screen to the cornea of ​​the first eye and providing the determined distance to the computer processor; and the computer processor is further configured to generate the display image and / or the second display image based also on the distance from the provided display screen to the cornea of ​​the first eye. Similarly, if applicable, the device includes a component for determining a distance from the display screen to the cornea of ​​the second eye and providing the determined distance to the computer processor; and the computer processor is further configured to generate the second display image based also on the distance from the provided display screen to the cornea of ​​the second eye. In some embodiments, the same component is used to determine the distance from the display screen to the cornea of ​​both eyes. In some embodiments, the device includes two different components, a first component for determining the distance from the display screen to the cornea of ​​the first eye, and a second component for determining the distance from the display screen to the cornea of ​​the second eye.

[0081] In a particularly preferred embodiment, there is provided an apparatus for image processing and display, the apparatus comprising: a computer processor operatively associated with the display screen and an eye tracker, the eye tracker configured to determine a gaze direction of a first eye of a person viewing the display screen and provide the determined gaze direction to the computer processor; Computer processors: Generate a display image from the received digital base image based on a gaze direction of the first eye received from the eye tracker, wherein: i. a central vision portion of the displayed image corresponding to a portion of the first eye's field of view that includes the determined gaze direction is unchanged compared to a corresponding portion in the base image; ii. a non-central portion of the display image that is distinct from the central portion is modified such that a visual characteristic of the non-central portion of the display image changes as compared to a corresponding visual characteristic of a corresponding portion of the base image, the modification degrading image quality of the non-central portion as compared to the corresponding portion of the base image; The generated display image is configured to be displayed on a display screen such that a first eye of a person views the display image on the display screen. wherein the computer processor is configured such that a size of a central vision portion of the displayed image corresponds to a field of view of the first eye of at least about 1° and not more than about 20° that includes the determined gaze direction of the first eye; the computer processor is configured such that the non-central vision portion of the generated image completely surrounds the central vision portion of the generated image and is at least 1% (and in some alternative preferred embodiments, at least about 30%) of the area of ​​the displayed image that is not the central vision portion; The computer processor is configured such that the modification that degrades the image quality of the non-central vision portion compared to the corresponding portion in the base image includes at least one modification selected from the group consisting of: reducing resolution; blurring; reducing contrast; reducing / increasing brightness; reducing color intensity; reducing or changing color palette, and combinations thereof. In some preferred embodiments, the modification that degrades the image quality of the non-central vision portion compared to the corresponding portion in the base image includes at least one modification selected from the group consisting of: reducing contrast; reducing / increasing brightness; reducing color intensity; reducing or changing color palette, and combinations thereof.

[0082] In a particularly preferred embodiment, there is provided an apparatus for image processing and display, the apparatus comprising: a computer processor operatively associated with the display screen and an eye tracker, the eye tracker configured to determine a gaze direction of a first eye of a person viewing the display screen and provide the determined gaze direction to the computer processor; Computer processors: Generate a display image from the received digital base image based on a gaze direction of the first eye received from the eye tracker, wherein: i. a central vision portion of the displayed image corresponding to a portion of the first eye's field of view that includes the determined gaze direction is unchanged compared to a corresponding portion in the base image; ii. a non-central portion of the display image that is distinct from the central portion is modified such that a visual characteristic of the non-central portion of the display image changes as compared to a corresponding visual characteristic of a corresponding portion of the base image, the modification degrading image quality of the non-central portion as compared to the corresponding portion of the base image; The generated display image is configured to be displayed on a display screen such that a first eye of a person views the display image on the display screen. wherein the computer processor is configured such that a size of the central vision portion of the displayed image corresponds to a field of view of the first eye of at least about 1° to about 20° including the determined gaze direction of the first eye; the computer processor is configured such that the non-central vision portion of the generated image completely surrounds the central vision portion of the generated image and is at least 1% (and in some alternative preferred embodiments, about 30%) of the area of ​​the displayed image that is not the central vision portion; The computer processor is configured such that the modification that degrades image quality of the non-central portion compared to the corresponding portion in the base image includes changing a value of a pixel of the non-central portion compared to a value of a corresponding pixel of the corresponding portion in the base image, wherein the magnitude and / or type of change to the pixel value is independent of the values ​​of any adjacent pixels in the base image.

[0083] Here, the display image and, if present, the second display image, comprise a central portion and a non-central portion, and in some examples of the priority document, the non-central portion is also referred to as the first portion and the central portion is also referred to as the second portion. [Brief description of the drawings]

[0084] Some embodiments of the present invention are described herein with reference to the accompanying drawings. The description, together with the drawings, will make apparent to those skilled in the art how some embodiments of the present invention can be implemented. The drawings are for illustrative purposes and do not attempt to show structural details of the embodiments in more detail than is necessary for a fundamental understanding of the present invention. For clarity, some objects depicted in the drawings are not drawn to scale.

[0085] [Figure 1] FIG. 1 is a schematic diagram of an apparatus in accordance with the teachings herein. [Figure 2A] FIG. 2A is a flow chart that generally illustrates some embodiments of methods according to the teachings herein. [Figure 2B] FIG. 2B is a flow chart that generally illustrates some embodiments of methods according to the teachings herein. [Figure 2C] FIG. 2C is a flow chart that generally illustrates some embodiments of methods according to the teachings herein. [Figure 2D]FIG. 2D is a flow chart that generally illustrates some embodiments of methods according to the teachings herein. [Diagram 3] FIG. 3 is a schematic diagram of an apparatus in accordance with the teachings herein. [Figure 4A] FIG. 4A is a schematic diagram of a field of view of an eye according to an embodiment of the teachings herein. [Figure 4B] FIG. 4B is a schematic diagram of a field of view of an eye according to an embodiment of the teachings herein. [Figure 5A] FIG. 5A is a schematic diagram of a display image or a second display image according to an embodiment of the teachings herein. [Figure 5B] FIG. 5B is a schematic diagram of a display image or a second display image according to an embodiment of the teachings herein. [Figure 6A] FIG. 6A is a schematic diagram of a different embodiment of a display image, which may also be considered as a second display image and which may also display a different embodiment of a mask image. [Figure 6B] FIG. 6B is a schematic diagram of a different embodiment of a display image, which may also be considered as a second display image and which may also display a different embodiment of a mask image. [Figure 6C] FIG. 6C is a schematic diagram of a different embodiment of a display image, which may also be considered as a second display image and which may also display a different embodiment of a mask image. [Figure 6D] FIG. 6D is a schematic diagram of a different embodiment of a display image, which may also be considered as a second display image and which may also display a different embodiment of a mask image. [Figure 6E] FIG. 6E is a schematic diagram of a different embodiment of a display image, which may also be considered as a second display image and which may also display a different embodiment of a mask image. [Figure 6F] FIG. 6F is a schematic diagram of a different embodiment of a display image, which may also be considered as a second display image and which may also display a different embodiment of a mask image. [Figure 6G] FIG. 6G is a schematic diagram of a different embodiment of a display image, which may also be considered as a second display image and which may also display a different embodiment of a mask image. [Figure 6H]FIG. 6H is a schematic diagram of a different embodiment of a display image, which may also be considered as a second display image and which may also display a different embodiment of a mask image. [Figure 6I] FIG. 6I is a schematic diagram of a different embodiment of a display image, which may also be considered as a second display image and which may also display a different embodiment of a mask image. [Figure 6J] FIG. 6J is a schematic diagram of a different embodiment of a display image, which may also be considered as a second display image, and which may also display a different embodiment of a mask image. [Figure 6K] FIG. 6K is a schematic diagram of a different embodiment of a display image, which may also be considered as a second display image and which may also display a different embodiment of a mask image. [Figure 7A] FIG. 7A is a schematic diagram of a base image. [Figure 7B] FIG. 7B is a schematic diagram of a mask image. [Figure 7C] FIG. 7C is a schematic diagram of a display image obtained from the base image of FIG. 7A and the mask image of FIG. 7B. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0086] Some embodiments relate to the field of image processing and display, and more particularly, but not exclusively, to methods and apparatus useful for processing images and displaying such images to a human subject. Some embodiments of the invention herein relate to methods and apparatus useful in the field of ophthalmology, and in some particular embodiments, to methods and apparatus useful for the non-invasive treatment and / or prevention of refractive errors in humans, particularly myopia, hyperopia and astigmatism.

[0087] As mentioned above, after birth, the human eye grows from about 1.8 cm in length to about 2.5 cm in length. Under ideal circumstances, the eye grows such that light entering the eye through the pupil is focused onto a small focal plane, thereby achieving hyperopia. Under non-ideal circumstances, the eye grows such that light entering the eye through the pupil is not focused onto a focal plane, resulting in refractive errors such as myopia, hyperopia, and astigmatism.

[0088] It would be useful to have methods and devices that at least partially prevent and / or treat existing refractive errors during the development of the human eye, such that treated humans in adulthood have a reduced magnitude of refractive error or no refractive error at all. Preferably, such methods and devices are non-invasive.

[0089] Studies have shown that eye growth in humans and monkeys is affected by the light that reaches the retina, see for example Read et al., "Light exposure and eye growth in childhood," in Invest Ophthalmol Vis Sci 2015, 56(11), 6779-6787.

[0090] Other studies in monkeys have shown that the effects of light on eye development remain even when the optic nerve is no longer connected to the brain; apparently, light falling on the retina leads to local chemical and biological changes that affect eye development.

[0091] Also disclosed herein is a method of image processing to generate a display image that is displayed to a human.

[0092] Disclosed herein are non-invasive methods useful for the non-invasive treatment of existing refractive errors and / or the prevention of the onset of refractive errors, particularly myopia, hyperopia and astigmatism, in human subjects. Also disclosed are devices useful for carrying out the methods.

[0093] In some embodiments, the method includes generating and displaying a display image on a screen for viewing by a human eye, where a central portion of the display image and / or a distinct non-central portion of the display image are altered such that the image quality of the non-central portion of the second display image is lower than the image quality of the central portion of the second display image.

[0094] The method can be implemented using any device or combination of devices, such as a single computer processor performing all operations requiring a computer processor, or at least two computer processors, each performing at least some of the operations requiring a computer processor. In some preferred embodiments, the method is implemented using an apparatus embodiment in accordance with the teachings herein, such as those described herein above in the "Summary of the Invention" section.

[0095] 1 illustrates an apparatus 10 for implementing some embodiments of the teachings herein, the apparatus 10 including a computer processor in a box 12 operatively associated with a display screen 14 and an eye tracker 16. A human subject 17 having a first eye 18a and a second eye 18b views an image displayed on the display screen 14.

[0096] A flow chart 20 of an embodiment of a method according to the teachings herein is illustrated in FIG. 2A.

[0097] According to aspects of some embodiments of the teachings herein, there is provided a method, the method comprising: a. in box 22, determining (using the eye tracker 16) a gaze direction of a first eye 18a of a subject 17 viewing an image on a display screen 14 and providing the determined gaze direction to a computer processor; b. Following 'a', in box 26, generating, by a computer processor, from the received digital-based image (received in box 24), a display image for display on the display screen 14 to the first eye 18a based on the determined gaze direction of the first eye 18a, comprising: i. The central vision portion of the displayed image corresponding to the portion of the field of view of the first eye 18a that includes the determined gaze direction is: or is altered such that visual characteristics of the central vision portion of the displayed image are altered compared to corresponding visual characteristics of the central vision portion of the displayed image, the alteration improving image quality of the central vision portion compared to corresponding portions of the displayed image; ii. A non-central portion of the displayed image that is different from the central portion: either unchanged compared to corresponding portions in the base image; or modified such that visual characteristics of the non-foveal portions of the displayed image change compared to corresponding visual characteristics of corresponding portions in the base image; generating a display image having a lower image quality for non-central portions of the display image than for central portions of the display image; c. further comprising, in box 26 of FIG. 2A, displaying the generated display image on the display screen 14 such that the first eye 18a of the subject 17 views the display image on the display screen 14.

[0098] [Technical aspects of display image generation] As described above, a display image is generated from a base image based on the gaze direction of the subject's eyes determined, and the display image is displayed on a display screen.

[0099] As illustrated generally in flow chart 30 of FIG. 2B, in some embodiments, generating a display image and displaying the generated display image are two separate steps in which the display image is first generated and then displayed. Thus, in some embodiments, generating a display image includes generating the display image as an image data structure (box 26a of FIG. 2B), and displaying the generated display image is then displaying the image data structure on a display screen (box 26b of FIG. 2B). Typically, after being generated, the image data structure is temporarily stored in a computer's memory (e.g., RAM, ROM, or a combination thereof) and then sent to a GPU (graphics processing unit) for display on a display screen.

[0100] In some embodiments, a display image is generated from a base image by applying an image operator to the display image. As known to those skilled in the art, an image operator transforms an input image (the base image) into an output image (the base image).

[0101] <local operator> In some embodiments, the operator is a local operator, i.e., an operator in which the value of a pixel in the display image depends not only on the value of the corresponding pixel in the base image, but also on the values ​​of pixels in the neighborhood of the corresponding pixel in the base image. Exemplary such embodiments include blur operators.

[0102] In embodiments in which the base image is a monochrome image, such that each pixel has a single grayscale intensity value, the local operator is applied to the grayscale intensity values ​​of the pixels in the base image.

[0103] In embodiments where the base image is a color image consisting of three color sub-images (R, G, B), the local operator is applied to only one of the three color sub-images (only the R sub-image, only the G sub-image, or only the B sub-image), to two of the three color sub-images (only the R and G sub-images, only the R and B sub-images, or only the G and B sub-images), or to all three sub-images.

[0104] When a local operator is applied to two or three color sub-images, in some embodiments the same operator is applied to two of the color sub-images, and in some embodiments it is applied to all three color sub-images.

[0105] When a local operator is applied to either two or three color sub-images, in some embodiments, two different local operators are applied: one local operator is applied to the first color sub-image and a different local operator is applied to the second color sub-image.

[0106] Alternatively, if a local operator is applied to all three color sub-images, in some embodiments three different local operators are applied: each local operator is applied to a different color sub-image.

[0107] <point operator> In some preferred embodiments, the operators are point operators, ie operators where the value of a pixel in the display image depends only on the value of the corresponding pixel in the base image.

[0108] The use of point operators enables implementation of an embodiment in which a modification that degrades the image quality of a non-focal portion compared to a corresponding portion in the base image includes changing the value of a pixel in the non-focal portion compared to the value of a corresponding pixel in the corresponding portion in the base image, where the magnitude and / or type of change to the pixel value is independent of the values ​​of any neighboring pixels in the base image.

[0109] If the base image is a monochrome image, the point operator is applied to the grayscale intensity values ​​of the pixels in the base image.

[0110] In embodiments where the base image is a color image, the point operator is applied to only one of the three color sub-images (only the R sub-image, only the G sub-image, or only the B sub-image), to three of the three color sub-images (only the R and G sub-images, only the R and B sub-images, or only the G and B sub-images), or to all three sub-images.

[0111] When a point operator is applied to two or three color sub-images, in some embodiments the same point operator is applied to two of the color sub-images, and in some embodiments it is applied to all three color sub-images.

[0112] When a point operator is applied to either two or three color sub-images, in some embodiments, two different point operators are applied: one point operator is applied to the first color sub-image and a different point operator is applied to the second color sub-image.

[0113] Alternatively, if a point operator is applied to all three color sub-images, in some embodiments three different point operators are applied: each point operator is applied to a different color sub-image.

[0114] Exemplary point operators include adding / subtracting a numerical value from pixels of the base image corresponding to the non-central vision portion, and multiplying / dividing pixel values ​​of the base image by the numerical value. In some embodiments, the numerical value is a constant for the entire non-central vision portion. In some alternative embodiments, the value of the numerical value varies as a function of the distance between the pixel of the central vision portion and the boundary.

[0115] <Local operators along with point operators> In some embodiments where the base image is a color image, a point operator is applied to a first of the three color sub-images, a local operator is applied to a second of the three color sub-images, and no operator is applied to a third of the three color sub-images.

[0116] In some embodiments where the base image is a color image, a point operator is applied to a first and a second of the three color sub-images, and a local operator is applied to a third of the three color sub-images.

[0117] In some embodiments where the base image is a color image, a local operator is applied to a first and a second of the three color sub-images, and a point operator is applied to a third of the three color sub-images.

[0118] <Generating a display image using a mask image> As illustrated generally in flow chart 31 of FIG. 2C, in some alternative embodiments, generating a display image and displaying the generated image includes: box 26' generating a partially transparent mask image based on the determined viewing direction; box 26 ″ generating a display image by combining the generated mask image with the base image (received in box 24 ); and then a box 26''' for displaying the generated display image on a display screen.

[0119] In some embodiments, the use of such a mask image can be thought of as applying a point operator to a base image to generate a display image.

[0120] Similar to the embodiment described with reference to FIG. 2B, in some embodiments, generating the display image includes generating the display image as an image data structure (box 26'' in FIG. 2C), and displaying the generated display image includes thereafter displaying the image data structure on a display screen (box 26''' in FIG. 2C). Typically, once generated, the image data structure is temporarily stored in a computer's memory (e.g., RAM, ROM or a combination thereof) and then sent to a GPU (graphics processing unit) for display on the display screen.

[0121] The generation of the mask image (box 26' in FIG. 2C) involves generating image data structures constituting the mask image. Typically, once generated, the image data structures constituting the mask image are at least temporarily stored in the computer's memory (e.g., RAM, ROM or a combination thereof). The mask image is partially transparent, meaning that the mask image includes a non-degraded central vision portion (transparent portion of the image mask) and a degraded non-central vision portion. The position of the central vision portion is set with reference to the determined gaze direction.

[0122] To generate a display image (box 26'' in FIG. 2C), the generated mask image is combined with the received base image in any suitable manner, such as, for example, pixel-by-pixel addition of the mask image to the base image, subtraction of the mask image from the base image, and multiplication / division of the base image and the mask image.

[0123] In a preferred embodiment, the non-degraded central vision portion of the mask image has pixel values ​​such that after combination of the mask image and the base image, the central vision portion of the display image has the same or better image quality as the central vision portion of the base image, whereas the degraded non-central vision portion of the mask image has pixel values ​​such that after combination of the mask image and the base image, the non-central vision portion of the display image has degraded (poorer image quality) than the central vision portion of the base image.

[0124] As illustrated generally in flowchart 32 of FIG. 2D, in some alternative embodiments, generating a display image and displaying the generated image includes first generating a partially transparent mask image and then simultaneously displaying the base image and the mask image on a display screen.

[0125] In some embodiments, the use of such a mask image can be thought of as applying a point operator to a base image to generate a display image.

[0126] The simultaneous display of the base image and the mask image on the display screen is the simultaneous generation and display of the display image on the display screen. Thus, in some embodiments: generating the display image includes generating a mask image (box 26' in FIG. 2D) including a non-degraded central vision portion and a degraded non-central vision portion, and then displaying the mask image together with the base image on the display screen (box 26i in FIG. 2D) such that the display image is simultaneously generated and displayed. Some such embodiments are implemented on a computer running Windows as a GUI (Graphical User Interface). After the mask image (box 26') is generated, the mask image and the base image are sent together to a GPU and displayed simultaneously on the display screen in the usual manner (box 26i). The net effect is that a viewer of the display screen sees a display image according to the teachings herein, the display image being a combination of the base image and the mask image, as described above with reference to FIG. 2C. In typical such embodiments, the portions of the mask image that correspond to the central vision portions are non-degraded central vision portions (e.g., are "transparent"): when the base image and mask image are displayed together, the non-degraded central vision portions of the mask image do not affect the appearance of the central vision portions of the base image, and the portions of the base image that correspond to the central vision portions appear unchanged to the subject.

[0127] In contrast, the portions of the mask image that correspond to the non-central vision portions are degraded non-central vision portions, and when the base image and mask image are displayed together, the degraded non-central vision portions of the mask image change the appearance of the central vision portions of the base image, thereby degrading the appearance of the central vision portions. Stated slightly differently, the portions of the mask image that correspond to the non-central vision portions are degraded (e.g., partially transparent) so that when the mask image and base image are displayed together, the portions of the base image that correspond to the central vision portions appear to "overlap" with the mask image and are altered in a manner that degrades its image quality.

[0128] The use of a mask (however implemented, e.g., as described with reference to FIG. 2C or FIG. 2D ) enables implementation of an embodiment in which a modification that degrades the image quality of a non-central portion compared to a corresponding portion in the base image includes changing the value of a pixel of the non-central portion compared to the value of a corresponding pixel of the corresponding portion in the base image, where the magnitude and / or type of change to the pixel value is independent of the value of any neighboring pixels in the base image.

[0129] [Effects of viewing displayed images] The method can be performed on subjects of any age. For human subjects, the preferred age is typically between 2 and 18 years of age, during which the physical structure of the eye can more easily change as a result of visual stimulation.

[0130] Without wishing to be bound by any one theory, it is currently believed that practicing the present methods effects biological changes that alter the growth of components of the eye, e.g., affecting the physical growth of the eye and the development of the optical portion of the eye, and in some embodiments non-invasively treats and / or prevents the development of refractive errors such as myopia, hyperopia, and astigmatism.

[0131] Without wishing to be bound by any one theory, it is currently believed that the more a subject views display images on a display screen according to the teachings herein, the greater the beneficial effect will be felt.Since it is believed that one of the main causes of refractive errors such as myopia in children is indoor viewing of images on a screen, in a preferred embodiment, the method is carried out on as many, and preferably all, display screens that treated subject views during the course of a day.

[0132] Specifically, it is currently believed that when the eye views a generated display image, a non-central portion of the retina of the first eye perceives the non-central portion of the display image, and such perception affects the growth and physical development of the eye, for example, the length of the eyeball and the curvature of the cornea. As a result, application of some embodiments of the method according to the teachings herein to a subject susceptible to the development of refractive errors, such as myopia, hyperopia, astigmatism, prevents the development of the refractive error or reduces the ultimate severity of the developed refractive error. Similarly, application of some embodiments of the method according to the teachings herein to a subject already suffering from a refractive error, such as myopia, hyperopia, or astigmatism, stops the progression of the existing refractive error or even reduces the severity of the existing refractive error.

[0133] [Application of the method to a monocular subject] In some embodiments, the method is applied to only one eye of the subject, i.e., only one eye (the first eye) sees the display image generated from the received digital-based image. In such embodiments, only the first eye receives the beneficial effect of perceiving two portions of the display image in accordance with the teachings herein. In such embodiments, the display image is displayed on a screen such that the first eye sees the display image, but the second eye cannot see the display image. Such an embodiment can be illustrated with a modification of FIG. 1 such that the second eye 18b is covered with an eye patch and only the first eye 18a can see the image displayed on the display screen 14. Such a modification is not illustrated for the sake of simplicity.

[0134] [Displaying the same image to both eyes] In some preferred embodiments, the method is applied simultaneously to both eyes of the subject, so that both the first eye and the second eye see the same display image. In such embodiments, both the first eye and the second eye receive the beneficial effect of perceiving two parts of the display image according to the teachings herein. Thus, in some embodiments, the method further includes: displaying the generated display image on a display screen (i.e., the same display screen as the first eye, or a display screen different from the display screen for the first eye, for example, on a VR headset with two separate screens, one for each eye) so that the second eye of the subject sees the display image.

[0135] In some such embodiments, the display images are displayed at the same location on the same display screen for both eyes to view simultaneously. Such an embodiment is suitable, for example, for implementing the method on a computer or television display screen that is viewed simultaneously by both eyes. Such an embodiment is illustrated in FIG. 1, where a first eye 18a and a second eye 18b can simultaneously view the same display image displayed on a display screen 14.

[0136] Alternatively, in some embodiments, the display images are alternately (rather than simultaneously) displayed on the same screen at the same location as each eye sees, for example, on a display screen configured to alternate when the subject is wearing shutter glasses. Such an embodiment is illustrated in Figure 3, where subject 17 is wearing glasses 34, which are shutter glasses whose operation is coordinated to the alternating display of display images on display screen 14, as known in the art, such that each of eyes 18a and 18b alternately sees the same display image displayed on display screen 14. Also illustrated in Figure 3 is a range finder 35 (e.g., an XL-Maxsonar-EZ2 by Maxbotix, Inc., Fort Mill, South Carolina, USA) useful for implementing some embodiments of the teachings herein by providing distances to eyes 18a and / or 18b to a processor that generates the display images, and in some embodiments, a second display image as described later in this specification.

[0137] Alternatively, in some embodiments, the display images are displayed on the same screen, but in different locations for each eye to view, for example, when the method is implemented on a VR headset that includes a single screen that is split into left and right eye portions, such an embodiment is not shown in the figures for simplicity.

[0138] Alternatively, in some embodiments, the display image is displayed on a different screen for each eye to view, for example, when the method is implemented on a VR headset in which each eye is provided with its own physically distinct display screen, such an embodiment not shown in the figures for the sake of simplicity.

[0139] [Displaying a different image to each eye] In some embodiments, the method is applied such that the first eye displays a display image as described above, and the second eye displays a second display image different from the display image. Such an embodiment allows both the first eye and the second eye to receive the beneficial effect of perceiving two portions of the display image in accordance with the teachings herein. Thus, in some embodiments, the method further comprises, simultaneously with 'a' and 'b' described above for the first eye: d. determining a gaze direction of a second eye of the subject (person) viewing the second eye display screen and providing the determined gaze direction to a computer processor; e. Following 'c', generating, by the computer processor, a second display image from the received digital-based image for display on a second eye display screen to the second eye based on the determined gaze direction of the second eye, comprising: i. a central viewing portion of the second displayed image corresponding to a portion of the field of view of the second eye that includes the determined gaze direction: or is altered such that visual characteristics of the central vision portion of the second display image are altered compared to corresponding visual characteristics of the central vision portion of the second display image, the alteration improving image quality of the central vision portion compared to corresponding portions of the second display image; ii. A non-central portion of the second displayed image that is different from the central portion is: either unchanged compared to corresponding portions in the base image; or modified such that visual characteristics of the non-foveal portions of the second display image change compared to corresponding visual characteristics of corresponding portions in the base image; generating a second display image having a lower image quality for non-central vision portions than for central vision portions of the second display image; f. Displaying the generated second display image on a second eye display screen such that the second eye of the subject (person) sees the second display image on the second eye display screen.

[0140] In such an embodiment, the display image is displayed on the screen such that the second eye cannot see the display image, and the second display image is displayed on the screen such that the first eye cannot see the second display image.

[0141] As illustrated in flowchart 20 of FIG. 2A, flowchart 30 of FIG. 2B, and flowchart 32 of FIG. 2C, the process is substantially the same as for generating the display image, and therefore, for the sake of brevity, a separate flowchart for the process for generating the second display image is not presented herein.

[0142] In some embodiments, the base image is a stereoscopic base image that includes two sub-images, a left eye base sub-image and a right eye base sub-image, that make up a stereoscopic image pair. In such embodiments, the display image and the second display image are each generated from the appropriate base partial image. For example, if the first eye is the left eye, the display image is generated from the left eye base sub-image and the second display image is generated from the right eye base sub-image. Alternatively, if the first eye is the right eye, the display image is generated from the right eye base sub-image and the second display image is generated from the left eye base sub-image. In such an embodiment, the display image and the second display image are displayed stereoscopically to the subject in an appropriate manner, for example, on a display screen configured for autostereoscopic viewing (this embodiment is illustrated in FIG. 1), on a display screen configured for alternating display to a subject wearing shutter glasses (in this embodiment, where glasses 34 are shutter glasses, as illustrated in FIG. 3), on a VR headset in which each eye is provided with its own screen or its own portion of a screen (not shown for simplicity), or where the display image and the second display image are an anaglyph pair configured for display to a user wearing anaglyph glasses (in this embodiment, where glasses 34 are anaglyph glasses, as illustrated in FIG. 3).

[0143] Alternatively, in some embodiments, the base image is a monoscopic base image. In some such embodiments, the display image and the second display image are displayed on the same screen for each eye to view, for example, on a display screen configured for alternating display when the subject is wearing shutter glasses (in this embodiment, as illustrated in FIG. 3, where glasses 34 are shutter glasses), if the display image and the second display image are an anaglyph pair configured for display to a user wearing anaglyph glasses (in this embodiment, as illustrated in FIG. 3, where glasses 34 are anaglyph glasses), if the display screen is configured for autostereoscopic viewing (in this embodiment, as illustrated in FIG. 1), or if the method is implemented on a VR headset that includes a single screen split into left and right eye portions (not shown for simplicity).

[0144] Alternatively, in some embodiments, the display image and the second display image are displayed on different screens for each eye to view, for example when the method is performed on a VR headset in which each eye is provided with its own physically distinct display screen (not shown for simplicity).

[0145] In some such embodiments, the non-central portions of the display image and the second display image are the same size, or in some embodiments, the non-central portions of the display image and the second display image are different sizes.

[0146] In some such embodiments, the non-central portion of the displayed image and the non-central portion of the second displayed image are the same shape, or in some embodiments, the non-central portion of the displayed image and the non-central portion of the second displayed image are different shapes.

[0147] In some such embodiments, the central viewing portion of the display image and the central viewing portion of the second display image are the same size, or in some embodiments, the central viewing portion of the display image and the central viewing portion of the second display image are different sizes.

[0148] In some such embodiments, the centrally viewed portion of the display image and the centrally viewed portion of the second display image are the same shape, or in some embodiments, the centrally viewed portion of the display image and the centrally viewed portion of the second display image are different shapes.

[0149] In some such embodiments, the modifications performed on the base image to obtain the display image are different from the modifications performed on the base image to obtain the second display image. Some such embodiments are used when it is desired to have different effects on the development of each eye.

[0150] Alternatively, in such an embodiment, the modifications made on the base image to obtain the display image are the same as the modifications made on the base image to obtain the second display image. It is important to note that in such an embodiment, the display image and the second display image are not necessarily identical. For example, the location of the modifications is based on the determined gaze directions of the two eyes, which are not necessarily identical. For example, in an embodiment where the base image is a stereo base image, the two display images are not necessarily different.

[0151] [Display screen] The generated display image is displayed on a display screen such that the subject's first eye (and in some embodiments the second eye) views the generated display image, and in some embodiments the generated second display image is displayed on the display screen such that the subject's second eye views the generated second display image.

[0152] In some embodiments, the method is performed on a display screen (e.g., LCD, LED, plasma) that is intended to be viewed from a distance of at least 10 cm (measured from the subject's cornea to the screen surface). In some such embodiments, the display screen is at least 100 cm 2 0.25mm, ...

[0153] In some embodiments, the displaying includes generating a display image and a second display image as an anaglyph pair and displaying (simultaneously or in parallel) the two generated images as the anaglyph pair on a display screen to a subject wearing anaglyph glasses.

[0154] In some embodiments, the displaying includes alternating display of the generated images to each eye of the subject wearing shutter glasses, with the rate and time of alternation coordinated with the actuation of the shutter glasses so that each eye sees the appropriate generated image. As noted above, in some embodiments, both eyes see the same generated display image, but in alternative embodiments, a first eye sees a display image and a second eye sees a second display image.

[0155] In some embodiments, the displaying is performed on a display screen configured for autostereoscopic viewing (also known as glassesless 3D), and the display image is generated and displayed according to autostereoscopic methods known to those skilled in the art. Similarly, in some embodiments, the displaying is performed on a display screen configured for autostereoscopic viewing, and the display image and the second display image are generated and displayed according to autostereoscopic methods known to those skilled in the art.

[0156] In some embodiments, the method is carried out using a display screen or screen of a VR (Virtual Reality) headset. Typically, a VR headset is a device in which at least 80% of the subject's visual field receives visual information from the screen or screen of the headset. The screen or screen of the VR headset is of any technology (e.g., LED, LCD, plasma). Typically, but not necessarily, the screen or screen of the VR headset is placed at a distance of 15 cm or less from the subject's cornea.

[0157] In some embodiments, the VR headset has a display screen for displaying an image to the left eye and another display screen for displaying an image to the right eye. In such embodiments, the display image and a corresponding second display image are respectively displayed on different display screens of the VR headset, with each image being displayed on the appropriate display screen, thereby ensuring that the second display image is displayed on the screen such that the first eye cannot see the second display image, and that the display image is displayed on the screen such that the second eye cannot see the display image.

[0158] In some embodiments, the VR headset has a single display screen for displaying images to both eyes, with a left portion of the display screen being used to display images to only the left eye and a right portion of the display screen being used to display images to only the right eye. In such embodiments, the display image and the second display image are displayed on different portions of the VR headset's screen, with each image being displayed on an appropriate portion of the display screen, thereby ensuring that the second display image is displayed on the display screen such that the first eye cannot see the second display image, and that the display image is displayed on the display screen such that the second eye cannot see the display image.

[0159] [Image display rate] Typically, determining the eye's gaze direction, generating a display image (and if relevant, a second display image) from a received digital-based image, and displaying the generated display image (and if relevant, the generated second display image) are performed repeatedly, and in preferred embodiments at a rate of 10 Hz or greater, more preferably 30 Hz or greater.

[0160] Determining the gaze direction of one or two eyes of a human subject is well known and can be performed using any suitable device or combination of devices, for example a commercially available eye tracker such as Tobii (Danderyd Municipality, Sweden).

[0161] In some embodiments, multiple display images are generated based on a single determined gaze direction of a first eye, and, if applicable, multiple second display images are generated based on a single determined gaze direction of a second eye.

[0162] In some examples, the received base image is a still image (e.g., text) intended to be displayed on a display screen for a relatively long period of time, e.g., longer than 1 / 30 seconds, e.g., at least 0.5 seconds, at least 1 second. In such cases, a series of different display images are generated from the same base image and displayed on the display screen, each different display image being generated based on a different determined viewing direction, and, if applicable, a series of different second display images are generated from the same base image and displayed on the display screen.

[0163] In some examples, the received base images are frames of a video having a predetermined frame rate (fps - frames per second). In a preferred such example, a single display image (and, if applicable, a single second display image) is generated from the single corresponding frame and displayed on a display screen.

[0164] In some preferred such embodiments, the rate of determining the gaze direction of the first eye (and, if applicable, the second eye), the rate of generating a display image from a base image (and, if applicable, the rate of generating a second display image from the base image), and the rate of displaying the generated display images (and, if applicable, the rate of displaying the generated second display image) are performed at the frame rate of the video.

[0165] Alternatively, in some embodiments, the rate of determining the gaze direction of the first eye (and, if applicable, the second eye), the rate of generating a display image from a base image (and, if applicable, the rate of generating a second display image from the base image), and the rate of displaying the generated display images (and, if applicable, the rate of displaying the generated second display image) are performed at a rate that is less than the frame rate of the video.

[0166] Alternatively, in some embodiments, the rate of determining the gaze direction of the first eye (and, if applicable, the second eye), the rate of generating the display image from the base image (and, if applicable, the rate of generating the second display image from the base image), and the rate of displaying the generated display images (and, if applicable, the rate of displaying the generated second display images) are performed at a rate faster than the frame rate of the video. In some such embodiments, several frames of the video are used as base images to generate a plurality of display images (and, if applicable, a plurality of second display images).

[0167] [Digital-based image received] The base image is any suitable image for display to the subject. As discussed above, in some embodiments, the base image is a monoscopic image, and in some embodiments, the base image is a stereoscopic image pair including a left eye base sub-image and a right eye base sub-image. In some embodiments, the base image is a still image, and in some embodiments, the base image is a frame from a movie. In some embodiments, the base image is all or a portion of the scene the subject is viewing from which the base image is isolated. In some embodiments, the base image is all or a portion of a stored scene, e.g., a scene that is a frame or a portion of a frame from a movie or video game. In some embodiments, the base image is all or a portion of a captured scene (e.g., a scene captured by one or more cameras, and in some embodiments captured in real time), from which a display image is generated and displayed to the subject, in a preferred embodiment in real time.

[0168] [Generation of display images from received digital-based images] 4A and 4B, in accordance with the methods of the teachings herein, the field of view 36 of an eye (either the first eye or the second eye) viewing a scene 38 is divided into at least two portions: a first non-central portion 40 and a second central portion 42. In FIG. 4B, an additional third non-central portion 44 of the field of view 36 is also shown.

[0169] The display image or second display image according to the teachings of this specification includes non-central portions corresponding to the non-central portions of the field of view of each eye, i.e., is displayed on the display screen such that the non-central portions of the field of view of the viewing eye (44 in Figures 4A and 4B) perceive the non-central portions of the display image or second display image.

[0170] Additionally, the display image or the second display image includes a central portion that corresponds to the central portion of the eye's field of view, i.e., is displayed on the display screen such that the central portion of the viewing eye's field of view (42 in Figures 4A and 4B) perceives the central portion of the display image or the second display image.

[0171] 5A illustrates an eye 18 (first eye or second eye) viewing an image 46a (display image or second display image) displayed on a display screen 14 (e.g., a computer display screen). The field of view 36 of the eye 18 is larger than the display screen 14. The image 46a displayed on the display screen 14 includes two portions, a non-central portion 48 of the image 46a corresponding to the non-central portion 40 of the field of view 36 of the eye 18, and a central portion 50 of the image 46a corresponding to the central portion 42 of the field of view 36 of the eye 18. To generate the image 46a from the base image, a gaze direction 52a of the eye 18 was determined immediately prior to generating the image 46a.

[0172] 5B illustrates eye 18 (first eye or second eye) viewing image 46b (display image or second display image) displayed on display screen 14, which image 46b includes two portions, a non-central portion 48 of image 46b corresponding to a non-central portion 40 of field of view 36 of eye 18, and a central portion 42 of image 46b corresponding to a central portion 42 of field of view 36 of eye 18. To generate image 46b from the base image, a gaze direction 52b of eye 18 is determined immediately prior to generating image 46b, which gaze direction 52b is different from the gaze direction 52a used to generate image 46a.

[0173] [Central vision part of the displayed image and the second displayed image] <Position of central vision relative to line of sight> As described above, the central viewing portion of the displayed image corresponds to a portion of the field of view of the first eye that includes the determined gaze direction of the first eye, and the central viewing portion of the second displayed image corresponds to a portion of the field of view of the second eye that includes the determined gaze direction of the second eye.

[0174] In some embodiments, the central viewing portion of the display image corresponds to a portion of the first eye's field of view that is centered on the determined gaze direction of the first eye. Alternatively, in some embodiments, the central viewing portion of the display image corresponds to a portion of the first eye's field of view that is not centered on the determined gaze direction of the first eye. Similarly, where applicable, in some embodiments, the central viewing portion of the second display image corresponds to a portion of the second eye's field of view that is centered on the determined gaze direction of the second eye. Alternatively, in some embodiments, the central viewing portion of the second display image corresponds to a portion of the second eye's field of view that is not centered on the determined gaze direction of the second eye.

[0175] 4A and 4B show the angular dimension 54 of the central portion 42 of the visual field 36 of a subject's eye.

[0176] In Figures 5A and 5B it can be seen how the dimensions of the central portion 42 of images 46a and 46b correspond to the angular dimension 54 of the central portion 42 of the field of view 36 of eye 18. In Figures 5A and 5B, the central portion 42 of images 46a and 46b, as well as the central portion 42 of the field of view 36 of eye 18, are centered about a respective gaze direction 52a or 52b.

[0177] <Size of central vision> As is known in the art, a normal human eye has multiple substantially concentric regions with different resolutions, from lowest to highest: the foveal field is about 2°, the central field is about 5°, the paracentral field is about 8°, the parafoveal field is about 10°, and the macular field is about 18°.

[0178] According to some embodiments of the teachings herein, the central viewing portion of the display image and / or the second display image corresponds to a portion of the visual field of each eye that includes the line of sight and has an angular dimension of at least about 1° and not more than about 20°. On a display screen viewed from a distance of 50 cm, an angular dimension of 1° corresponds to about 0.88 cm, and an angular dimension of 20° corresponds to a linear dimension on the display screen of about 17.6 cm.

[0179] Additionally or alternatively, in some preferred embodiments, the central visual portion of the display image and / or the second display image corresponds to a visual portion of each eye that includes the line of sight and has an angular dimension of about 2° or more.

[0180] Additionally or alternatively, in some preferred embodiments, the central viewing portion of the display image and / or the second display image corresponds to a portion of the field of view of each eye having an angular dimension, including the line of sight, of about 16° or more and about 12° or less, about 8° or less, or even about 5° or less.

[0181] According to some preferred embodiments of the teachings herein, the central viewing portion of the displayed image corresponds to a portion of the first eye's field of view that includes the line of sight and has an angular dimension of about 2° to about 8°. Similarly, according to some preferred embodiments of the teachings herein, where applicable, the central viewing portion of the second displayed image corresponds to a portion of the second eye's field of view that includes the line of sight and has an angular dimension of about 2° to about 8°. On a display screen viewed from a distance of 50 cm, an angular dimension of 2° corresponds to about 1.7 cm, and an angular dimension of 8° corresponds to a linear dimension on the display screen of about 7 cm.

[0182] As known to those skilled in the art, and as described immediately above herein, for a given angular dimension of the field of view, the physical size (e.g., in pixels and / or millimeters) of the corresponding display image and / or the corresponding second region of the second display image depends on the distance between the cornea and the display screen. In some embodiments, the method further includes: providing the computer processor with a distance from the display screen to the cornea of ​​the first eye prior to generating the display image 'b'; the generation of the display image is also based on the distance from the provided display screen to the cornea of ​​the first eye. Similarly, where applicable, in some embodiments, the method further includes: providing the computer processor with a distance from the display screen to the cornea of ​​the second eye prior to generating the second display image 'e'; the generation of the second display image is also based on the distance from the provided display screen to the cornea of ​​the second eye. Specifically, the desired angular size of the central portion of the field of view of the eye is converted to a physical dimension of the central visual portion of the display image or the second display image on the display screen based on the received distance, e.g., using basic geometry. In some embodiments, the distance provided to generate the display image and the distance provided to generate the second display image are the same.

[0183] In some such embodiments, providing the distance from the display screen to the cornea of ​​the first eye and / or the second eye to the computer processor includes inputting the distance value or distance values ​​as parameters to the computer processor. In some embodiments, the distance from the display screen to the cornea is known and fixed prior to performance of the method (e.g., when the display screen is a component of VR goggles). In preferred such embodiments, the distance from the display screen to the cornea is provided to the computer processor as a stored parameter.

[0184] In some embodiments, the distance between the cornea and the display screen is not known a priori and / or may vary during the performance of the method (e.g., if the display screen is that of a computer, smartphone, tablet, or television). In some such embodiments, an estimated "typical" display screen to cornea distance is provided to the computer processor as a stored parameter. For example, in some embodiments, if the display screen is that of a smartphone, the estimated distance is set to 30 cm. For example, in some embodiments, if the display screen is that of a tablet or laptop / desktop computer, the estimated distance is set to 45 cm. For example, in some embodiments, if the display screen is that of a television, the estimated distance is set according to an ideal viewing distance for the screen size. For example, one skilled in the art might consider the ideal viewing distances for typical screen sizes to be: a 32 inch screen is ideally viewed from 1.37m, a 40 inch screen is ideally viewed from 1.62m, a 50 inch screen is ideally viewed from 2.13m, a 60 inch screen is ideally viewed from 2.56m, a 70 inch screen is ideally viewed from 2.99m, and an 80 inch screen is ideally viewed from 3.41m.

[0185] In some alternative embodiments where the distance between the cornea and the display screen is not known a priori and / or may vary during the performance of the method, the actual distance is determined and then provided to the computer processor. Thus, in some such embodiments, providing the computer processor with the distance from the display screen to the cornea of ​​the first eye includes determining the distance between the display screen and the cornea of ​​the subject's first eye, which determined distance is used to generate the display image, and in some embodiments also generates the second display image. Similarly, where applicable, in some embodiments, providing the computer processor with the distance between the display screen and the cornea of ​​the second eye includes determining the distance between the display screen and the cornea of ​​the subject's second eye, which determined distance is used to generate the second display image. Such distance determination may be performed in any suitable manner using any suitable device or combination of devices. In some embodiments, the distance is determined using a dedicated range finder (e.g., using a commercially available IR or ultrasonic range finder such as range finder 35 illustrated in FIG. 3). Additionally or alternatively, in some embodiments where the display screen is functionally associated with a camera (as is typical of smartphones, tablets, laptop computers, many desktop computers, and some television displays), determining the distance is determined from an analysis of an acquired image of a person viewing the screen. For example, when the apparatus illustrated in FIG. 1, and optionally FIG. 3, is configured to determine the distance from the display screen to the cornea, where there is a reason not to use a range finder 35, this is preferably performed using a camera integrated into the frame of the display screen 14, not depicted. Typically, in such embodiments, there is a set-up procedure in which the human subject on whom the method is performed views the screen at one or more predetermined distances. At each of the one or more predetermined distances, a reference image is acquired. The size of one or more features in the reference image, or the distance between features such as the head and eyes, is correlated with the corresponding predetermined distance and is used as a reference value for determining the distance from the display screen to the cornea during the actual performance of the method.

[0186] <Shape of central vision> The shape of the central viewing portion of the display image and / or the second display image on the display screen is any suitable shape. In some embodiments, the shape of the central viewing portion on the display screen is a circle (as illustrated in FIG. 5A and FIG. 5B). Alternatively, in some embodiments, the shape of the central viewing portion of the display image and / or the second display image is a shape different from a circle, for example, an ellipse, a square, or a rectangle. In preferred such embodiments, the smallest dimension of the central viewing portion corresponds to an angular dimension of about 1° or less, and the largest dimension of the central viewing portion corresponds to an angular dimension of about 20° or less.

[0187] The shape of the central vision portion in some embodiments is described in further detail herein below.

[0188] <Changing the central vision of the image> As discussed above, the central viewing portion of the display image is either unaltered compared to the corresponding portion in the base image; or is altered such that the visual characteristics of the central viewing portion of the display image change compared to the corresponding visual characteristics of the corresponding portion in the base image, which alters the image quality of the central viewing portion compared to the corresponding portion in the base image. Similarly, where applicable, the central viewing portion of the second display image is either unaltered compared to the corresponding portion in the base image; or is altered such that the visual characteristics of the central viewing portion of the second display image change compared to the corresponding visual characteristics of the corresponding portion in the base image, which alters the image quality of the central viewing portion compared to the corresponding portion in the base image.

[0189] In some embodiments, the central vision portion is not altered compared to the corresponding portion of the base image, i.e., the central vision portion is the same as the corresponding portion of the base image: what the eye perceives in the central portion of the field of view when viewing the display image or the second display image is the same as when the eye views the base image.

[0190] Alternatively, in some embodiments, a centrally viewed portion of the display image is modified such that visual characteristics of the centrally viewed portion of the display image are changed compared to corresponding visual characteristics of the corresponding portion in the base image, which modification improves image quality of the centrally viewed portion compared to the corresponding portion in the base image. Similarly, where applicable, in some embodiments, a centrally viewed portion of the second display image is modified such that visual characteristics of the centrally viewed portion of the second display image are changed compared to corresponding visual characteristics of the corresponding portion in the base image, which modification improves image quality of the centrally viewed portion compared to the corresponding portion in the base image. The modification that improves image quality is any suitable modification known in the art of image processing. In some embodiments, such modification includes applying at least one image processing method selected from the group consisting of increasing contrast, sharpening, changing brightness, changing color, and combinations thereof to the corresponding portion of the base image.

[0191] As is known in the art, in some instances, a human subject has asymmetric vision, i.e., a vision deficiency that causes both eyes to perceive identically viewed images differently. In some preferred embodiments involving generating both a display image and a second display image, the modification to the central vision portion of the base image includes "balancing" the central vision portion of the display image and the central vision portion of the second display image so that they are perceived as more similar, or even identical, by each eye. Thus, in some embodiments in which a subject has an asymmetric vision deficiency such that the left and right eyes perceive identically viewed display images differently, modifying the portion of the base image that corresponds to the central vision portion of the display image and modifying the portion of the base image that corresponds to the central vision portion of the second display image together include compensating for the asymmetric vision deficiency, such that the central vision portion of the display image and the central vision portion of the second display image are perceived as more similar than they would be in the absence of such modification. In such embodiments, the modification of the corresponding portions of the base image to generate the display image and / or the central vision portion of the second display image includes: Varying the size (enlarging / reducing) of the central portion of the base image to obtain the central portion of the display image and / or the second display image; Varying the blur and / or sharpening of a centrally viewed portion of the base image to obtain a centrally viewed portion of the display image and / or the second display image; Varying (increasing / reducing) the luminance of a centrally viewed portion of the base image to obtain a centrally viewed portion of the display image and / or a second display image; Varying (increasing / reducing) the contrast of the centrally viewed portion of the base image to obtain the centrally viewed portion of the display image and / or the second display image; The present invention includes at least one image processing method selected from the group consisting of:

[0192] Alternatively, in some embodiments, a central viewing portion of the display image is modified such that visual characteristics of the central viewing portion of the display image change compared to corresponding visual characteristics of the corresponding portion in the base image, which modification changes the image quality of the central viewing portion relative to the corresponding portion in the base image. In some embodiments, such modification improves the image quality of the central viewing portion of the display image compared to the corresponding portion in the base image. Similarly, in some embodiments, a central viewing portion of the second display image is modified such that visual characteristics of the central viewing portion of the display image change compared to corresponding visual characteristics of the corresponding portion in the base image, which modification changes the image quality of the central viewing portion relative to the corresponding portion in the base image. In some embodiments, such modification improves the image quality of the central viewing portion of the second display image compared to the corresponding portion in the base image.

[0193] [Non-central part of displayed image / non-central part of visual field] As discussed above, in some embodiments, a display image is generated from the received digital base image, where non-central portions of the display image that are distinct from the central portions are either: unchanged compared to the corresponding portions in the base image; or are modified such that visual characteristics of the non-central portions of the display image change compared to the corresponding visual characteristics of the corresponding portions in the base image, resulting in a lower image quality for the non-central portions of the display image than the central portions of the display image. Similarly, where relevant, a second display image is generated from the received digital base image, where non-central portions of the second display image that are distinct from the central portions are either: unchanged compared to the corresponding portions in the base image; or are modified such that visual characteristics of the non-central portions of the second display image change compared to the corresponding visual characteristics of the corresponding portions in the base image, resulting in a lower image quality for the non-central portions of the second display image than the central portions of the second display image.

[0194] The relative orientation of the central and non-central vision portions in the display image and / or the second display image may be any suitable relative orientation. In some embodiments, the non-central vision portions are contiguous with the central vision portions. In some embodiments, the non-central vision portions of the display image at least partially surround the central vision portions. In some embodiments, the non-central vision portions of the display image completely surround the central vision portions. In Figures 5A and 5B, the non-central vision portions 48 of images 46a and 46b are contiguous with and completely surround the central vision portions 50 of the images.

[0195] The sizes of the non-central portions of the display image and the second display image may be any suitable size. In some embodiments, the radial dimension of the non-central portions of the display image corresponds to a first eye's field of view of at least about 2°. Similarly, where applicable, in some embodiments, the radial dimension of the non-central portions of the second display image corresponds to a first eye's field of view of at least about 2°. Sizes of the non-central portions according to other embodiments are listed in the Summary of the Invention above and will not be repeated here for brevity.

[0196] In some embodiments, the non-central viewing portion is at least 1% of the area of ​​the display image that is not the central viewing portion, for example constituting a thin ring surrounding the central viewing portion. Similarly, where applicable, in some embodiments, the non-central viewing portion is at least 1% of the area of ​​the second display image that is not the central viewing portion. In some preferred embodiments, the non-central viewing portion of the display image and / or the second display image is at least about 30% of the area of ​​the display image that is not the central viewing portion. In some preferred embodiments, the non-central viewing portion of the display image and / or the second display image is at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, at least about 95%, or even about 100% of the area of ​​the display image / second display image that is not the central viewing portion. In Figures 5A and 5B, the non-central viewing portion 48 of images 46a and 46b is 100% of the area of ​​the image that is not the central viewing portion 48.

[0197] In some embodiments, the non-central portions of the display image and / or the second display image constitute the balance of the display screen that is not the central portion of the display image and the second display image, respectively.

[0198] Alternatively, in some embodiments, the non-central portion of the display image and / or the second display image constitutes less than the balance of the display screen that is not a central portion of the display screen and the second display screen, respectively. In such embodiments, the non-central portion has an inner border having a shape that, in typical embodiments, is determined by the shape of the central portion. The non-central portion also has an outer border. The shape of the outer border of the non-central portion of the display image and / or the second display image can be any suitable shape, and in some embodiments is a shape selected from the group consisting of a circle, an ellipse, a polygon, a square, and a rectangle.

[0199] In some embodiments, non-central portions of the display image are not altered compared to corresponding portions of the base image. Similarly, where applicable, non-central portions of some second display images are not altered compared to corresponding portions in the base image.

[0200] In some preferred embodiments, the non-central portions of the display image are modified such that visual characteristics of the non-central portions of the display image change compared to corresponding visual characteristics of the corresponding portions in the base image, which modification changes the image quality of the non-central portions of the display image relative to the corresponding portions in the base image. In some embodiments, such modification improves the image quality of the non-central portions of the display image compared to the corresponding portions in the base image. In some preferred embodiments, such modification degrades the image quality of the non-central portions of the display image compared to the corresponding portions in the base image. Similarly, where applicable, in some preferred embodiments, the non-central portions of the second display image are modified such that visual characteristics of the non-central portions of the second display image change compared to corresponding visual characteristics of the corresponding portions in the base image, which modification changes the image quality of the non-central portions of the second display image compared to the corresponding portions in the base image. In some embodiments, such modification improves the image quality of the non-central portions of the second display image compared to the corresponding portions in the base image.

[0201] In some embodiments, the modification that degrades image quality of the non-central portions of the display image and / or the second display image compared to the corresponding portions in the base image includes: A reduction in resolution compared to the corresponding part of the base image; Blurred compared to the corresponding part of the base image; A reduction in contrast compared to the corresponding part of the base image; A reduction / increase in brightness compared to the corresponding part of the base image; A reduction in color intensity compared to the corresponding portion of the base image; A change or reduction in the color palette compared to the corresponding portion of the base image; The combination of these, The compound comprises at least one member selected from the group consisting of:

[0202] In some embodiments, the modification that degrades the image quality of the non-central portions of the display image and / or the second display image compared to the corresponding portions in the base image includes at least one member selected from the group consisting of: reducing resolution; blurring; reducing contrast; reducing / increasing brightness; reducing color intensity; reducing or changing color palette; and combinations thereof. In some embodiments, the modification that degrades the image quality of the non-central portions of the display image and / or the second display image compared to the corresponding portions in the base image includes reducing resolution. In some embodiments, the modification that degrades the image quality of the non-central portions of the display image and / or the second display image compared to the corresponding portions in the base image includes blurring. In some embodiments, the modification that degrades the image quality of the non-central portions of the display image and / or the second display image compared to the corresponding portions in the base image includes reducing contrast. In some embodiments, the modification that degrades the image quality of the non-central portions of the display image and / or the second display image compared to the corresponding portions in the base image includes reducing / increasing brightness.

[0203] In some embodiments, the alteration that degrades image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes a reduction in color intensity.

[0204] In some embodiments, the alteration that degrades the image quality of the non-central portions of the display image and / or the second display image compared to corresponding portions in the base image includes a reduction or change in the color palette.

[0205] In some embodiments, the changes to the visual characteristics of the non-focal portions of the display image are homogenous, i.e., the type and degree of modification is the same for the entire non-focal portions. Similarly, where applicable, in some embodiments, the changes to the visual characteristics of the non-focal portions of the second display image are homogenous.

[0206] Alternatively, in some embodiments, the changes to the visual characteristics of the non-central viewing portion of the display image are non-homogeneous, i.e., the type and degree of modification is not the same for the entire non-central viewing portion. Similarly, where applicable, in some embodiments, the changes to the visual characteristics of the non-central viewing portion of the second display image are not homogeneous. For example, in some embodiments, the modification is a gradient in which the degree of modification is progressively greater the closer to the central viewing portion. Alternatively, and more preferably, in some such embodiments, the modification is a gradient in which the degree of modification is progressively greater the further from the central viewing portion. Additionally or alternatively, in some embodiments, the non-central viewing portion has n distinct portions, n being an integer greater than 1, each distinct portion having a different modification. For example, in some embodiments, the central viewing portion includes two annular portions, an inner annular portion using a first type of modification and an outer annular portion using a second type of modification different from the first type of modification, and / or the inner annular portion has a first degree of modification and the outer annular portion has a second degree of modification different from the first degree of modification.

[0207] The degree of deterioration may be any suitable degree of deterioration. In some embodiments, the degree of deterioration may vary over the course of treatment, for example, depending on how the treatment treats a particular subject. For example, the visual acuity of a subject undergoing treatment is typically monitored at intervals of 3 to 6 months. If the subject's monitoring session indicates that the refractive error has significantly worsened during the pre-treatment period, the degree of deterioration is increased during the post-treatment period. On the other hand, if the subject's monitoring session indicates that the refractive error has remained stable or has only slightly worsened during the pre-treatment period, the degree of deterioration is maintained or decreased during the post-treatment period.

[0208] The initial degree of degradation (i.e., the degree of degradation when a course of treatment is initiated) may be any suitable degree of degradation and may be determined in any suitable manner, typically based on the experience of a person, such as an ophthalmologist. In some embodiments, a subject is shown a normal image that has been degraded to some degree with some modification. If the subject indicates that a particular degradation is one that makes it difficult to perceive previously visible details in the image, then that particular degradation is considered as the initial degree of degradation.

[0209] 6A-6K illustrate various embodiments of display images 46 displayed on display screen 14, with each display image 46 having a central portion 50 and a non-central portion 48. Also illustrated in Figure 6 is the gaze direction 52 of eye 18 used to generate display image 46.

[0210] 6A , central vision portion 50 is not circular, is not centered on line of sight 52, and is elongated toward the upper right-hand corner of display screen 14. Non-central vision portion 48 completely surrounds central vision portion 50 and constitutes 100% of the surface area of ​​display screen 14 that is not covered by central vision portion 50.

[0211] In FIG. 6B , central vision portion 50 is elliptical in shape centered on line of sight 52, shaped like an elliptical ring, and completely surrounded by non-central vision portion 48, which occupies approximately 10% of the surface area of ​​display screen 14 that is not covered by central vision portion 50.

[0212] 6C, central vision portion 50 is circular, not centered on line of sight 52, and is completely surrounded by non-central vision portion 48. Non-central vision portion 48 occupies approximately 50% of the surface area of ​​display screen 14 that is not covered by central vision portion 50.

[0213] 6D, central vision portion 50 is a circle centered about line of sight 52 and is completely surrounded by non-central vision portion 48. Non-central vision portion 48 is ring-shaped and occupies approximately 2% of the surface area of ​​display screen 14 that is not covered by central vision portion 50.

[0214] 6E, central vision portion 50 is a circle centered about line of sight 52 and is partially surrounded by non-central vision portion 48. Non-central vision portion 48 is a 190° arc and occupies approximately 2% of the surface area of ​​display screen 14 that is not covered by central vision portion 50.

[0215] 6F, central vision portion 50 is a circle centered on line of sight 52 and is completely surrounded by non-central vision portion 48. Non-central vision portion 48 is an elliptical ring and occupies approximately 20% of the surface area of ​​display screen 14 that is not covered by central vision portion 50.

[0216] 6G, central vision portion 50 is a circle centered on gaze direction 52 and is completely surrounded by non-central vision portion 48. Non-central vision portion 48 is two physically separate rings, an inner ring and an outer ring that are concentric with and continuous with central vision portion 50.

[0217] 6H, central vision portion 50 is a circle centered on line of sight 52 and is completely surrounded by non-central vision portion 48. Non-central vision portion 48 is star-shaped and occupies approximately 5% of the surface area of ​​display screen 14 that is not covered by central vision portion 50.

[0218] In Figure 6I, central vision portion 50 is elliptical, centered on gaze direction 52, and is partially surrounded by non-central vision portion 48. Non-central vision portion 48 is a non-contiguous ring made up of four separate, truncated pie shapes.

[0219] 6J illustrates a situation where viewing direction 18 is near the edge of screen 14. As a result, central vision portion 50, if not truncated, is a truncated circle centered about viewing direction 52. Non-central vision portion 48, by being truncated, is a truncated ring shape that partially surrounds central vision portion 50.

[0220] 6K, central vision portion 50 is a circle centered on line of sight 52 and is completely surrounded by non-central vision portion 48. Non-central vision portion 48 is a circular ring and occupies approximately 20% of the surface area of ​​display screen 14 that is not covered by central vision portion 50. The level of degradation of non-central vision portion 48 is a gradient, with greater degradation closer to central vision portion 50.

[0221] It is important to note that the component labeled 46 in Figures 6A-6K is a display image, but in related embodiments may also represent a second display image. Additionally, the component labeled 46 in Figures 6A-6K may also be considered to represent a mask image in embodiments that include a mask image.

[0222] Figures 7A, 7B and 7C show generally the base image 56 of Figure 7A, and the mask image 58 and display image 46 that are generated and displayed when the base image 56 and mask image 58 are displayed together on a display screen or when the base image 56 and mask image 58 are combined prior to display to generate the display image 46. In Figure 7B, the degraded non-central vision portion 60 and the non-degraded central vision portion 62 of the mask image 58 are shown. In Figure 7C, the central vision portion 50 and the non-central vision portion 48 of the display image 46 are shown.

[0223] [Determining the subject's eye gaze direction] As described above, the method taught herein includes determining a gaze direction of one or both eyes of a subject and generating a display image and / or a second display image based on the determined gaze direction or orientation.

[0224] The gaze direction of one or both eyes may be determined in any suitable manner, and in some preferred embodiments, an eye tracker is used. In the apparatus depicted in Figures 1 and 3, the gaze direction of both eyes 18a and 18b is determined using an eye tracker 16.

[0225] The display image generated based on the determined gaze direction of the first eye is such that the gaze direction of the first eye passes through the central vision portion of the display image. No matter in what direction the first eye moves relative to the display screen on which the display image is displayed, the display image is generated such that the gaze direction of the first eye passes through the central vision portion.

[0226] When applicable, the second display image generated based on the determined gaze direction of the second eye is such that the gaze direction of the second eye passes through a centrally viewed portion of the second display image, and the second display image is generated such that the gaze direction of the second eye passes through a centrally viewed portion of the second display image, regardless of in what direction the second eye moves relative to the display screen on which the second display image is displayed.

[0227] [Pupil size and pupil size determination device] In some embodiments, the size and / or shape and / or degree and / or type of modification of the base image to generate the central or non-central portion of the display image also depends on the determined pupil size of the first eye. Similarly, where applicable, in some embodiments, the size and / or shape and / or degree and / or type of modification of the base image to generate the central or non-central portion of the second display image also depends on the determined pupil size of the second eye.

[0228] Thus, in some embodiments, the method further includes, prior to generating display image 'b', providing a first eye pupil size to a computer processor; and generating the display image also based on the provided first eye pupil size. Additionally or alternatively, in some embodiments, the method further includes, prior to generating second display image 'e', ​​providing a second eye pupil size to a computer processor; and generating the second display image also based on the provided second eye pupil size.

[0229] Pupil size may be determined in any suitable manner using a suitable device or combination of devices, for example, it is well known in the art to determine pupil size using an eye tracker.

[0230] [Pupil size] In some embodiments, for any two different generated display images, the non-central portions of the display image generated when a larger pupil size is detected and provided to a computer processor are altered (preferably degraded to a lesser extent) than the non-central portions of the display image generated when a smaller pupil size is detected and provided to a computer processor. Similarly, in some embodiments, for any two different generated second display images, the non-central portions of the second display image generated when a larger pupil size is detected and provided to a computer processor are altered (preferably degraded to a lesser extent) than the non-central portions of the second display image generated when a smaller pupil size is detected and provided to a computer processor.

[0231] In some embodiments, for any two different generated display images, the central viewing portion of the display image generated when the larger pupil size is detected and provided to the computer processor is larger than the non-central viewing portion of the display image generated when the smaller pupil size is detected and provided to the computer processor. In some embodiments, for any two different generated second display images, the central viewing portion of the second display image generated when the larger pupil size is detected and provided to the computer processor is larger than the non-central viewing portion of the second display image generated when the smaller pupil size is detected and provided to the computer processor.

[0232] In some embodiments of the device, the device is configured to determine a pupil size of a first eye of a subject viewing a display screen and provide the determined pupil size to a computer processor, which is further configured to generate a display image and / or a second display image based also on the determined pupil size of the first eye, e.g., as described above. In some embodiments of the device, the device is configured to determine a pupil size of a first eye of a subject viewing a display screen and / or provide the determined pupil size to a computer processor, which is further configured to generate a display image based also on the determined pupil size of the first eye and generate a second display image based also on the determined pupil size of the second eye. Components that may be associated with such devices for determining the pupil size of one or both eyes are well known and include, for example, one or more cameras and some type of eye tracker, as described above.

[0233] [Eye movement compensation] Generally, during a given session in which a subject is viewing a display screen in accordance with the teachings herein, a central portion of the display image or the second display image is seen by the central vision of each eye, and a non-central portion of the display image or the second display image is seen by the more peripheral vision of each eye.

[0234] If the determination of gaze direction, the generation of the image, and the display of the generated image are sufficiently fast (e.g., faster than 60 Hz), the display screen or the person or subject looking at the screen may not notice any changes made to the image they see.

[0235] In particular, it has been found in some embodiments that when the present teachings are implemented using weaker computer processors or more complex image processing algorithms that are applied to a base image to generate a displayed image, the delay between determining the gaze direction and displaying the generated image can cause the foveal vision to perceive non-central portions of the displayed generated image, causing discomfort or irritation, especially when the non-central portions are degraded.

[0236] To overcome this, in some embodiments, the method comprises: and monitoring a velocity and amplitude of the first eye movement, and if the velocity and amplitude of the first eye movement is greater than a certain threshold, not displaying (or even generating) the display image and / or the second display image, and in some embodiments displaying the base image instead. The threshold is typically set according to the characteristics of the particular hardware.

[0237] In some embodiments, the method further includes determining a motion vector of the first eye's gaze direction, and if the determined motion vector of the first eye's gaze direction is greater than a threshold, the computer processor generates the display image and / or the second display image also based on the determined motion vector. The display image and / or the second display image are generated such that the central vision portion is sufficiently large and of the correct shape, so that the viewer is less likely to perceive that the non-central vision portion of the generated image is displayed in foveal vision. In some such embodiments, a larger motion vector results in the generation of a larger central vision portion. Additionally or alternatively, in some such embodiments, a larger motion vector results in the generation of a central vision portion having an elongated shape with a small dimension perpendicular to the determined motion vector and a large dimension parallel to the determined motion vector. Such a central vision having an elongated shape is illustrated in FIG. 6A, which is an elliptical shape of the central vision portion 50 when the eye's motion vector is toward the upper right corner of the screen 14. Similarly, in some embodiments, if applicable, the method further includes determining a motion vector of the second eye's gaze direction, and if the determined motion vector of the second eye's gaze direction is greater than a threshold, the computer processor generates a display image based on the determined motion vector as well. The second display image is generated such that the central vision portion is sufficiently large and of the correct shape, so that the viewer is less likely to perceive that the non-central vision portion of the generated second display image is displayed in foveal vision. In some such embodiments, a larger motion vector results in the generation of a larger central vision portion. Additionally or alternatively, in some such embodiments, a larger motion vector results in the generation of a central vision portion having an elongated shape with a small dimension perpendicular to the determined motion vector and a large dimension parallel to the determined motion vector, as illustrated in FIG. 6A.

[0238] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

[0239] As used in this specification, the terms "comprising," "including," "having," and grammatical variations thereof are deemed to specify stated features, integers, steps, or components, but do not exclude the addition of one or more additional features, integers, steps, components, or groups thereof.

[0240] As used herein, the indefinite articles "a" and "an" mean "at least one" or "one or more," unless the context clearly indicates otherwise.

[0241] As used herein, when a numerical value is preceded by the term "about," the term "about" is intended to indicate ±10%.

[0242] As used herein, a phrase of the form "A and / or B" means a selection from the group consisting of (A), (B) or (A and B). As used herein, a phrase of the form "at least one of A, B and C" means a selection from the group consisting of (A), (B), (C), (A and B), (A and C), (B and C) or (A and B and C).

[0243] Method and / or apparatus embodiments described herein may include performing or completing selected tasks manually, automatically, or a combination thereof. Some methods and / or apparatus described herein are implemented using components that are hardware, software, firmware, or a combination thereof. In some embodiments, some components are general-purpose components, such as a general-purpose computer or digital processor. In some embodiments, some components are dedicated or custom components, such as circuits, integrated circuits, or software.

[0244] For example, in some embodiments, some of the embodiments are implemented as a number of software instructions executed by a data processor, e.g., part of a general purpose computer or custom computer. In some embodiments, the data processor or computer includes volatile memory for storing instructions and / or data, and / or non-volatile storage, e.g., a magnetic hard disk and / or removable media, for storing instructions and / or data. In some embodiments, the implementation includes a network connection. In some embodiments, the implementation includes a user interface, generally consisting of one or more of an input device (e.g., allowing for input of commands and / or parameters) and an output device (e.g., allowing for reporting of parameters and results of operations).

[0245] It will be understood that certain features of the invention that are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as appropriate in other described embodiments of the invention. Certain features described in the context of various embodiments are not considered essential features of those embodiments, unless the embodiment is inoperable without those elements.

[0246] While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, the present invention is intended to embrace all such alternatives, modifications, and variations that fall within the scope of the appended claims.

[0247] Citation or identification of a reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.

[0248] Section headings are used to facilitate understanding of the specification and should not be construed as necessarily limiting.

Claims

1. 1. A method useful for treating existing refractive errors and / or preventing the development of refractive errors in a human subject, comprising: a. determining a gaze direction of a first eye of a subject viewing an image on a display screen and providing the determined gaze direction to a computer processor; b. following 'a', generating, by a computer processor, a display image from the received digital-based image for display on the display screen to the first eye based on the determined gaze direction of the first eye, comprising: i. a central viewing portion of the displayed image corresponding to a portion of the first eye's field of view that includes the determined gaze direction is: unaltered compared to a corresponding portion in the base image; or altered such that visual characteristics of the central vision portion of the display image change compared to corresponding visual characteristics of the corresponding portion in the base image, the alteration improving image quality of the central vision portion compared to the corresponding portion in the base image; ii. a non-central portion of the displayed image that is different from the central portion: unaltered compared to corresponding portions in the base image; or altered such that visual characteristics of the non-foveal portions of the display image change compared to corresponding visual characteristics of corresponding portions in the base image. generating a display image having a lower image quality for the non-central vision portion than for the central vision portion of the display image; and c) displaying the generated display image on the display screen such that the first eye of the subject views the display image on the display screen.

2. The method of claim 1 , further comprising displaying the generated display image on the display screen such that a second eye of the subject views the display image on the display screen.

3. Together with 'a' and 'b': d. determining a gaze direction of the subject's second eye viewing a second eye display screen and providing the determined gaze direction to a computer processor; e. following 'c', generating, by a computer processor, a second display image from the received digital-based image for display on the second eye display screen to the second eye based on the determined gaze direction of the second eye, comprising: i. a central viewing portion of the second displayed image corresponding to a portion of the field of view of the second eye that includes the determined gaze direction is: unaltered compared to a corresponding portion in the base image; or altered such that visual characteristics of the central vision portion of the second display image change compared to corresponding visual characteristics of the corresponding portion in the base image, the alteration improving image quality of the central vision portion compared to the corresponding portion in the base image; ii. a non-central viewing portion of the second display image that is different from the central viewing portion: unaltered compared to corresponding portions in the base image; or altered such that visual characteristics of the non-foveal portions of the second display image change compared to corresponding visual characteristics of the corresponding portions in the base image. generating a second display image having a lower image quality for the non-central vision portion than for the central vision portion of the second display image; f. displaying the generated second display image on a second eye display screen such that the second eye of the subject sees the second display image on the second eye display screen; The method of claim 1 further comprising:

4. 4. The method of claim 1, wherein a size of the central vision portion of the displayed image corresponds to a field of view of the first eye of at least about 1° to about 20° including the determined gaze direction of the first eye.

5. The method of any one of claims 1 to 4, wherein the central vision portion of the display image is not altered compared to the corresponding portion of the base image.

6. 5. A method according to any one of claims 1 to 4, wherein the central vision portion of the display image is modified such that visual characteristics of the central vision portion of the display image change compared to corresponding visual characteristics of a corresponding portion in the base image, the modification improving image quality of the central vision portion compared to the corresponding portion in the base image.

7. The method of any one of claims 1 to 6, wherein the non-central vision portion of the displayed image completely surrounds the central vision portion.

8. The method of any one of claims 1 to 7, wherein approximately 100% of the area of ​​the displayed image that is not the central vision portion is the non-central vision portion.

9. The method according to any one of claims 1 to 8, wherein the non-central vision portion is at least 1% and up to about 80% of the area of ​​the displayed image that is not the central vision portion.

10. 10. The method of claim 1, wherein the non-central portions of the display image are modified such that visual characteristics of the non-central portions of the display image change compared to corresponding visual characteristics of corresponding portions of the base image, the modification degrading image quality of the non-central portions compared to the corresponding portions of the base image.

11. The method of claim 10, wherein the alterations that degrade image quality of the non-central vision portions compared to corresponding portions in the base image include at least one member selected from the group consisting of: reduced resolution; reduced contrast; reduced / increased brightness; reduced color intensity; reduced or changed color palette, and combinations thereof.

12. The method of claim 10, wherein the alterations that degrade image quality of the non-central vision portions compared to corresponding portions in the base image include at least one member selected from the group consisting of: reducing resolution; blurring; reducing contrast; reducing / increasing brightness; reducing color intensity; reducing or changing the color palette, and combinations thereof.

13. 11. The method of claim 10, wherein the modification that degrades image quality of a non-central portion compared to a corresponding portion in the base image includes changing a value of a pixel of the non-central portion compared to a value of a corresponding pixel in the corresponding portion in the base image, and the magnitude and / or type of change to the pixel value is independent of the value of any neighboring pixels in the base image.

14. Generating the display image includes generating the display image as an image data structure; The method of any one of claims 1 to 13, wherein displaying the generated display image comprises subsequently displaying the generated image data structure on the display screen.

15. Generating the display image includes: generating a mask image independent of the base image, the mask image having a non-degraded central vision portion and a degraded non-central vision portion; combining the mask image with the base image to generate the display image as an image data structure; The method of any one of claims 1 to 14, wherein displaying the generated display image comprises subsequently displaying the generated image data structure on the display screen.

16. Generating the display image includes: generating a mask image independent of the base image, the mask image including a non-degraded central vision portion and a degraded non-central vision portion; Thereafter, displaying the mask image together with the base image on the display screen such that the display image is both generated and displayed simultaneously.

17. providing said computer processor with a distance from a display screen to the cornea of ​​a first eye prior to generating said displayed image 'b'; The method of any one of claims 1 to 16, further comprising: generating the display image also based on a provided distance from the display screen to a cornea of ​​a first eye.

18. 1. An apparatus for image processing and display comprising: a computer processor operatively associated with a display screen and an eye tracker, the eye tracker configured to determine a gaze direction of a first eye of a person viewing an image on the display screen and provide the determined gaze direction to the computer processor; The computer processor: configured to generate a display image from a received digitally based image based on a gaze direction of the first eye received from the eye tracker, wherein: i. a central viewing portion of the displayed image corresponding to a portion of the first eye's field of view that includes the determined gaze direction: unaltered compared to a corresponding portion in the base image; or altered such that visual characteristics of the central vision portion of the display image change compared to corresponding visual characteristics of the corresponding portion in the base image, the alteration improving image quality of the central vision portion compared to the corresponding portion in the base image; ii. A non-central portion of the displayed image that is different from the central portion: unaltered compared to corresponding portions in the base image; or altered such that visual characteristics of the non-foveal portions of the display image change compared to corresponding visual characteristics of the corresponding portions in the base image. generating a lower image quality for the non-central viewing portion of the displayed image than the central viewing portion of the displayed image; and displaying the generated display image on the display screen such that the first eye of the person views the display image on the display screen.

19. 20. The apparatus of claim 18, wherein the display screen is configured to enable a second eye of the person to view a displayed image produced on the display screen.

20. an eye tracker configured to determine a gaze direction of a second eye of a person viewing the display screen and provide the determined gaze direction of the second eye to the computer processor; The computer processor: configured to generate a second display image from the received digitally based image and based on a gaze direction of the second eye received from the eye tracker: i. a central viewing portion of the second displayed image corresponding to a portion of the field of view of the second eye that includes the determined gaze direction: unaltered compared to a corresponding portion in the base image; or altered such that visual characteristics of the central vision portion of the second display image change compared to corresponding visual characteristics of the corresponding portion in the base image, the alteration improving image quality of the central vision portion compared to the corresponding portion in the base image; ii. a non-central viewing portion of the second display image that is different from the central viewing portion: unaltered compared to a corresponding portion in the base image; or altered such that visual characteristics of the non-foveal portions of the second display image change compared to corresponding visual characteristics of the corresponding portions in the base image. generating a lower image quality for the non-central viewing portion of the second display image than the central viewing portion of the second display image; 20. An apparatus as claimed in any one of claims 18 to 19, further comprising: displaying the generated second display image on a display screen functionally associated with the computer processor such that the second eye of the person views the second display image on the display screen.

21. 21. The apparatus of claim 18, wherein the computer processor is configured to configure a size of a central vision portion of the displayed image to correspond to a field of view of the first eye of at least about 1° to about 20° including the determined gaze direction of the first eye.

22. Apparatus according to any one of claims 18 to 21, wherein the computer processor is configured such that centrally viewed parts of a displayed image are not altered compared to corresponding parts in the base image.

23. 23. The apparatus of claim 18, wherein the computer processor is configured to modify the base image such that visual characteristics of a central vision portion of the generated display image are changed compared to corresponding visual characteristics of a corresponding portion in the base image, the modification improving image quality of the central vision portion compared to the corresponding portion in the base image.

24. Apparatus according to any one of claims 18 to 23, wherein the computer processor is configured such that the non-central vision portion of the displayed image completely surrounds the central vision portion.

25. 25. An apparatus according to any one of claims 18 to 24, wherein the computer processor is configured such that approximately 100% of the area of ​​the displayed image other than the central vision portion is the non-central vision portion.

26. 25. The apparatus of claim 18, wherein the computer processor is configured such that the non-central vision portion is at least 1% and no more than about 80% of an area of ​​the displayed image that is not the central vision portion.

27. The apparatus of any one of claims 18 to 26, wherein the computer processor is configured to modify the base image such that visual characteristics of non-central portions of the generated display image are changed compared to corresponding visual characteristics of corresponding portions in the base image, the modification degrading image quality of the non-central portions compared to corresponding portions in the base image.

28. 28. The device of claim 27, wherein the alterations that degrade image quality of non-central portions of the displayed image compared to corresponding portions in the base image include at least one member selected from the group consisting of: reducing resolution; reducing contrast; reducing / increasing brightness; reducing color intensity; reducing or changing the color palette, and combinations thereof.

29. 28. The device of claim 27, wherein the alterations that degrade image quality of non-central portions of the displayed image compared to corresponding portions in the base image include at least one member selected from the group consisting of: reducing resolution; blurring; reducing contrast; reducing / increasing brightness; reducing color intensity; reducing or changing the color palette, and combinations thereof.

30. 31. The apparatus of claim 19, wherein the modification that degrades the image quality of the non-central portion compared to a corresponding portion in the base image comprises changing a value of a pixel of the non-central portion compared to a value of a corresponding pixel in the corresponding portion in the base image, the magnitude and / or type of change to the pixel value being independent of the value of any adjacent pixels in the base image.

31. the configuration of the computer processor for generating a display image includes configuration for generating the display image as an image data structure; Apparatus according to any one of claims 19 to 30, wherein the configuration of the computer processor for displaying a generated display image comprises configuration for subsequently displaying the generated image data structure on the display screen.

32. The configuration of the computer processor for generating a display image comprises: generating a mask image independent of the base image, the mask image having a non-degraded central vision portion and a degraded non-central vision portion; combining the generated mask image with the base image to generate a display image as an image data structure; Apparatus according to any one of claims 19 to 31, wherein the arrangement of the computer processor for displaying a generated display image is arranged to subsequently display the generated image data structure on the display screen.

33. The computer processor for generating and displaying a display image may be configured to: A configuration in which a mask image independent of the base image is generated, the mask image including a non-degraded central vision portion and a degraded non-central vision portion; Thereafter, displaying the mask image together with the base image on the display screen so as to simultaneously generate and display a display image.

34. 34. Apparatus according to any one of claims 19 to 33, wherein the computer processor is configured to generate a display image based also on a distance from a provided display screen to the cornea of ​​the first eye.

35. 1. A method for image processing and display comprising: a. determining a gaze direction of a first eye of a person viewing an image on a display screen and providing said determined gaze direction to a computer processor; b. following 'a', generating, by a computer processor, from the received digital-based image, the display image for display on the display screen to the first eye based on the determined gaze direction of the first eye, comprising: i. a central viewing portion of the displayed image corresponding to a portion of the first eye's field of view that includes the determined gaze direction is: unaltered compared to a corresponding portion in the base image; or altered such that visual characteristics of the central vision portion of the display image change compared to corresponding visual characteristics of the corresponding portion in the base image, the alteration improving image quality of the central vision portion compared to the corresponding portion in the base image; ii. a non-central vision portion of the displayed image that is different from the central vision portion; unaltered compared to corresponding portions in the base image; or altered such that visual characteristics of the non-foveal portions of the display image change compared to corresponding visual characteristics of corresponding portions in the base image. generating a display image having a lower image quality for the non-central vision portion than for the central vision portion of the display image; and c) displaying the generated display image on the display screen such that the first eye of the person views the display image on the display screen.

Images