Computer-implemented method and system for interactive measurement of eye refractive error, reading glasses addition power, and diopter

Abstract

System and method for interactive measurement of eye refractive error and addition and power of reading glasses without optical components that change the target vergence. The system can measure the distance between any one or two boundaries of the clear vision range from the user's eye in one direction or two perpendicular directions. The measurement values, along with the user's age, can be used to estimate the spherical-cylindrical refraction, addition, and power of reading glasses. The system can use different sizes, orientations, and colors of the target, and these characteristics can change with the aforementioned distance or user interaction.

Description

Field of the Invention

[0001] The present invention relates to the fields of optometry, visual optics, physiological optics, electronics, and computers. Specifically, the present invention relates to methods and systems for measuring the near point, far point, and their focusing errors of the human eye, which can lead to myopia, hyperopia, astigmatism, and presbyopia. Background of the Invention

[0003] A perfect eye forms a clear image of an infinitely distant object on the retina. Thus, the far point (FP) of a perfect eye is at infinity. As the distance between the eye and the object gets closer and closer, the eye adjusts to keep the object in focus, which is mainly a change in the curvature of the lens inside the eye. Once the minimum distance of accommodation is reached, the lens cannot become more curved, and at this time, the object is located at the near point (NP) of the eye. In optometry, distance is usually expressed in diopters (D), which is the reciprocal of meters (m). The refractive distance between the FP and NP of the eye is called the amplitude of accommodation (AA). Since the FP of a perfect eye is at infinity, it corresponds to 0D, and the NP of a perfect eye can be located at (for example) 0.1 m, which corresponds to 10D. In this case, the AA is 10D.

[0004] The human eye suffers from aging, and people approaching 45 years old or older suffer from presbyopia - the lens of the eye loses the ability to change shape. The amplitude of accommodation of the human eye decreases with age, from approximately 20D in infancy to 0D in old age, when the eye loses the ability to image near objects on the retina. Many reports have documented the relationship between age and the maximum accommodation change of the human eye [1][2].

[0005] In addition, the human eye can have focusing errors due to optical defects of the refractive surfaces (cornea and lens) and / or the mismatch between refractive power and axial length, which is called refractive error. This error (causing the far point to be closer than infinity (myopia) or farther than infinity (hyperopia)) makes the eye unable to form a clear image on the retina and leads to deterioration of visual quality and the need for optical correction.

[0006] Refractive errors that can be corrected by glasses, contact lenses, intraocular lenses, or refractive surgery can be divided into spherical errors (myopia or hyperopia), cylindrical errors (astigmatism), and presbyopia. Astigmatism is the change in the optical power of the eye along the meridian (direction), causing the far point to be divided into two (meridians), for example, one corresponding to the horizontal part of the image and the other corresponding to the vertical part. This results in different visual qualities of the images of vertical objects (such as a fence) and horizontal objects (such as a striped dress) and may cause dizziness, double vision, and an overall loss of visual quality. Many authors have confirmed that during the accommodation process, the degree and axis of astigmatism change little [3][4].

[0007] Astigmatism can be present in the relaxed or accommodated eye, which means that the FP and NP can each split into two. Each can correspond to two distances (depending on the orientation of the object); namely, the distal far point (dFP) and the proximal far point (pFP), and the distal near point (dNP) and the proximal near point (pNP). These four distances correspond to the boundaries of the clear vision interval (BICV).

[0008] Due to the light scattering of the optical medium (which is a function of wavelength), the positions of the FP and NP depend on the spectral composition (color) of the object imaged on the retina by the optical elements of the eye [5]. For example, a person with a myopia of 2D looking at an object on a black background, the FP of a white, blue, and red object may be located at distances of 0.5 m, 0.4 m, and 0.53 m respectively. The chromatic aberration of the eye is known and similar among different people, so the FP and NP for any given wavelength (color) can be calculated [6].

[0009] Before correction, the type and value of the refractive error must be determined through a procedure called optometry, which involves finding the combination of spherical and cylindrical lenses that correct the aforementioned focusing error of the eye. Optometry can be performed by using specialized optical instruments that can measure the light leaving the eye (objective optometry), or by a trained clinician using a chart and a set of trial lenses (subjective optometry).

[0010] Due to the presence of higher-order monochromatic aberrations [7] and the well-documented errors in objective optometry and subjective optometry determined by clinicians [8, 9], the human eye cannot achieve perfect focusing even after spherocylindrical correction. In addition, the optimal refraction may vary with the task and the object being observed

[10] . For example, if the goal of optometry is to read an eye chart or letters, it depends on the size of the letters. A person with low myopia can see large letters without correction but needs correction to see small letters. Similarly, a person with low presbyopia can see medium or large fonts but cannot see small print. Therefore, the positions of the FP and NP depend on the object size

[11] and the refraction of the subject.

[0011] There are numerous patents and patent applications regarding systems and methods for measuring refractive errors, some of which include techniques for finding the cylindrical lens that corrects the astigmatism of the eye

[12] . However, these patents and patent applications are all about obtaining measurements when the object is at the FP of the eye. In addition, these patents and applications are all based on using an optical system to correct the optical vergence in the object image, rather than based on changing the true physical distance to the aforementioned object. Furthermore, these patents and patent applications do not include changes in the object size (such as the size of the target on the screen) determined by the aforementioned distance, which is essential for the image size formed by the optical elements of the eye to depend on the distance.

[0012] To the best of the authors' knowledge, there are no previously published patent applications that cover systems and methods for interactively measuring eye refractive error, reading glasses power, and add power (and such systems and methods are based on measurements of the distance between the subject's head and the device, where the object size is constantly changing and the subject can interactively select a BICV based on subjective preference). Such a system can be implemented using modern electronic devices, including a screen, camera, sensors, and a processor.

[0013] References

[0014] 1. Duane A. Studies in Monocular and Binocular Accommodation, with Their Clinical Application. Transactions of the American Ophthalmological Society. 1922; 20: 132 - 57.

[0015] 2. Jackson E. Amplitude of Accommodation at Different Periods of Life. California state journal of medicine. 1907; 5(7): 163 - 6.

[0016] 3. Borish IM. Clinical refraction, 3rd ed. Chicago: Professional Press, 1970.

[0017] 4. Bannon RE. A study of astigmatism at the near point with special reference to astigmatic accommodation. Am J Optom Arch Am Acad Optom. 1946; 23: 53 - 75.

[0018] 5. Sivak JG, Mandelman T. Chromatic dispersion of the ocular media. Vision Res 1982; 22: 997–1003.

[0019] 6. Thibos LN, Ye M, Zhang X, Bradley A. The chromatic eye: a new reduced-eye model of ocular chromatic aberration in humans. Appl Opt 1992; 31: 3594–3600.

[0020] 7. Charman WN. Wavefront aberration of the eye: a review. Optom Vis Sci 1991; 68: 574–583.

[0021] 8. Bullimore, M.A., Boyd, T., Mather, H.E., & Gilmartin, B. (1988). Near retinoscopy and refractive error. Clinical and Experimental Optometry, 71(4), 114 - 118.

[0022] 9. Bullimore, M.A., Fusaro, R.E., & Adams, C.W. (1998). The repeatability of automated and clinician refraction. Optometry and vision science: official publication of the American Academy of Optometry, 75(8), 617 - 622.

[0023] 10. López - Gil, N., Peixoto - de - Matos, S.C., Thibos, L.N., & González - Méijome, J.M. (2012). Shedding light on night myopia. Journal of Vision, 12(5):4, 1–9.

[0024] 11. Heath G.G. (1956). The influence of visual acuity on accommodative responses of the eye. Am. J. Opt & t. & drchs Am. Acad. Oprom. 33. 513 - 524.

[0025] 12. Limon, Ofer. System and method for measurement of refractive error of an eye based on subjective distance metering. Patent. WO / 2014 / 195951. Summary of the Invention

[0027] The present invention relates to a computer-implemented method and system for interactively measuring eye refractive error, reading glasses addition power, and diopter, based on an interactive subjective measurement of the distance between the subject's head and an electronic device corresponding to any BICV.

[0028] The system described herein includes the following components of an electronic device:

[0029] a. A distance measurement circuit, including passive components (such as one or more cameras) or active components (such as transmitters, detectors) or others, or any combination of the foregoing.

[0030] b. A user interface, including an electronic screen with a touch surface or a keypad or a microphone or others, or any combination of the foregoing.

[0031] c. A control circuit and a processing circuit, including a processor, a memory module, a wired or wireless connection between the system module and components and a remote network or others, or any combination of the foregoing.

[0032] The method proposed herein may include the following steps:

[0033] a. Obtain information about the user, such as age (AGE), gender, geographical location, the eye to be tested, or others, or any combination of the foregoing.

[0034] i. According to some embodiments of the present invention, obtain user information, including designing a user interface module to prompt the user to input such information into the user interface.

[0035] ii. According to some embodiments of the present invention, obtain user information, including automatically detecting such information based on the user's avatar from a camera included in the electronic device or other databases.

[0036] b. Display a target (such as one or more letters or visual targets, a geometric pattern, or a still or moving picture, or others, or any combination of the foregoing) on an electronic screen.

[0037] i. According to some embodiments of the present invention, displaying an object on an electronic screen includes changing the size, shape, rotation, color, background color, or other features of any of the foregoing objects, or any combination of the foregoing, in accordance with the user's interaction with the electronic device using the user interface.

[0038] ii. According to some embodiments of the present invention, displaying an object on an electronic screen includes changing the size, shape, rotation, color, background color, or other features of any of the foregoing objects, or any combination of the foregoing, while changing the distance between the user's head and the electronic device.

[0039] c. Changing the distance between the user's head and the electronic device to optimize the subjective visual quality of the object according to a certain criterion.

[0040] i. According to some embodiments of the present invention, changing the distance between the user's head and the electronic device includes having the user hold a device in their hand and move the device closer to or farther from the user's face.

[0041] ii. According to some embodiments of the present invention, changing the distance between the user's head and the electronic device includes placing one or more reflective surfaces, electronic devices, and changing the distance between the device and the reflective surface or the distance between the head and the reflective surface, or a combination of the foregoing.

[0042] iii. According to some embodiments of the present invention, changing the distance between the user's head and the electronic device includes having a third party (such as another person, another instrument, or others, or any combination of the foregoing) change the distance between the user's head and the electronic device.

[0043] d. Measuring any one or more BICVs to meet a certain visual quality standard.

[0044] i. According to some embodiments of the present invention, measuring any one or more BICVs may include presenting a spatially characterized object to the user at an angle α on an electronic screen and measuring the corresponding distance between the user and the object.

[0045] ii. According to some embodiments of the present invention, measuring any one or more BICVs may include presenting a spatially detailed object to the user at a different angle β, where β may be perpendicular to angle α, and measuring the corresponding distance between the user and the object.

[0046] iii. According to some embodiments of the present invention, measuring any one or more BICVs may include designing a distance measurement circuit embedded in the electronic device to perform the measurement.

[0047] iv. According to some embodiments of the present invention, measuring any one or more BICVs may include performing the measurement using an external instrument, such as a ruler, a rangefinder, or others, or any combination of the foregoing.

[0048] v. According to some embodiments of the present invention, visual quality criteria may include an acuity criterion (such as resolving lines, letters, etc.), a contrast sensitivity criterion (such as resolving shades of gray), a color discrimination criterion (such as distinguishing colors), subjective clarity, or others, or any combination of the foregoing.

[0049] e. Calculate the eye refractive error, the power and addition of the reading glasses based on the measured BICV, information about the object (such as the color of a certain target), information about the user (such as age, gender, or others), or any other or combination of the foregoing.

[0050] f. Save the eye refractive error, the power and addition of the reading glasses calculated from the measured BICV, information about the object (such as the color of a certain target), information about the user (such as age, gender, or others), or any other or combination of them.

[0051] Brief Description of the Drawings

[0052] The following detailed description and the accompanying drawings are used to further illustrate the nature and advantages of the present invention:

[0053] Figure 1 FIG. is a schematic diagram of an example system for interactively measuring eye refractive error and the addition and power of reading glasses in an embodiment of the present invention.

[0054] Figure 2 FIG. is a block diagram of an example electronic device for interactively measuring eye refractive error and the addition and power of reading glasses in an embodiment of the present invention, in which a camera is incorporated into the distance measurement module and a screen is incorporated into the user interface.

[0055] Figure 3 FIG. is an example view of an example screen of an electronic device for interactively measuring eye refractive error and the addition and power of reading glasses in an embodiment of the present invention.

[0056] Figure 4 FIG. is a flowchart of an example subroutine for changing a target as the distance between the head and the electronic device changes in an embodiment of the present invention.

[0057] Figure 5 FIG. is a flowchart of an example program for interactively measuring eye refractive error and the addition and power of reading glasses in an embodiment of the present invention.

[0058] Detailed Description

[0059] The present invention is directed to computer - implemented systems and methods for interactively measuring eye refractive errors and the addition power and diopter of reading glasses. The method is based on subjective interactive measurement of the distance between a user's head and an electronic device, particularly corresponding to any one or more of the BICV. In some embodiments, the present invention provides systems and methods that enable a user to accurately measure the refractive error of his or her or another person's eyes, with or without wearing an optical corrector.

[0060] Figure 1 is a schematic diagram of an exemplary computer - implemented system for interactively measuring eye refractive errors and the addition power and diopter of reading glasses, based on one embodiment of the present invention. System 100 may include a distance - measuring circuit 110, a user interface 120, a control circuit 130, a processing circuit 140, a memory 150, and a communication circuit 160. In some embodiments, one or more components of the device may be combined or omitted. In some embodiments, system 100 may include Figure 1 additional components not included therein, or combinations of any of the foregoing components.

[0061] System 100 may include any suitable type of electronic device with a distance - measuring circuit for measuring the distance between a user's head and the device. For example, system 100 may include any of the following devices equipped with a camera and photosensitive elements: a mobile phone, a tablet, a "smart" TV, a personal digital assistant (PDA), a notebook or desktop computer, a stand - alone camera or video recorder, and any other suitable device. The electronic device included in system 100 is preferably (but not limited to) a portable device.

[0062] The distance - measuring circuit 110 may include any circuit, transmitter, and detector for measuring the distance between a user's head or a part thereof and the electronic device. In some embodiments, the distance - measuring circuit 110 may include a passive system that includes one or more cameras for capturing an image of the user's head and a circuit for calculating the distance between the user's head or a part thereof and the aforementioned image. In some embodiments, the distance - measuring circuit 110 may include an active system that includes one or more transmitters and detectors for measuring the aforementioned distance.

[0063] The user interface 120 may include any suitable mechanical means for interacting with the user, such as one or more screens, speakers, touch surfaces, keypads, microphones, or any combination of the foregoing or the aforementioned. For example, in some embodiments, the user interface 120 may include a touch - sensitive electronic screen for displaying targets and receiving user input.

[0064] The control circuit 130 can include any type of circuit, such as a processor, a microcontroller, and connections, for controlling the functions, operations, and executions of the electronic devices incorporated into the system 100. In addition, the control circuit 130 can be electrically coupled to other components of the system 100 (or any combination of the foregoing). For example, in some embodiments of the present invention, the control circuit 130 can send control signals to the user interface 120 to set the user interface for receiving inputs from the user or giving instructions to the user.

[0065] The processing circuit 140 can include any type of circuit, such as a processor, a microcontroller, and connections, for processing data from the distance measurement circuit 110, the user interface 120, and other components of the system 100 (or any combination of the foregoing), for calculating the spherical and cylindrical errors of the eye and the power and addition power of the reading glasses. In addition, the processing circuit 140 can be electrically coupled to other components of the system 100 (or any combination of the foregoing). For example, in some embodiments of the present invention, the processing circuit 140 can send signals to the control circuit 130 to set the user interface 120 or the distance measurement circuit 110.

[0066] The memory 150 can include one or more storage media, such as any type of internal or external memory, such as HDD, SSD, RAM, ROM, EPROM, Flash EEPROM, flash memory cards such as SD (i.e., Secure Digital) cards or CF (i.e., Compact Flash) cards, or any other type of memory suitable for the electronic devices in the system 100.

[0067] The communication circuit 160 can include any circuit suitable for connecting the electronic devices in the system 100 to a communication network and transmitting data, and the foregoing connection and transmission can use any suitable protocol, such as Wi-Fi (such as the 802.11 protocol), cellular protocols (such as GSM, GPRS, CDMA, EDGE, LTE) or any other communication protocol or any combination of the foregoing.

[0068] Figure 2 is a block diagram of an exemplary electronic device 200 for interactively measuring eye refractive error and the addition power and power of reading glasses, based on an embodiment of the present invention.

[0069] The electronic device 200 can be very similar to the electronic devices included in the system 100 shown in Figure 1 and has the same description as the components of the latter. For example, the electronic device 200 can also include a memory 250 and a communication circuit 260, which can be substantially similar to the components, the memory 150, and the communication circuit 160 of the electronic devices in the system 100, respectively, or any combination of the others or the foregoing.

[0070] The distance measurement circuit 210 may be similar to the distance measurement circuit 110 and measure the distance between the user's head 270 and the electronic device 200 using any suitable technique or combination of techniques.

[0071] The user interface 220 may be connected to the control circuit 230 and the processing circuit 240. The user interface (120; 220) may be configured to provide instructions to the user via visual instruction information (see 304 in Figure 3 ), audio information, or other user interface methods or any combination of the foregoing methods. Additionally, the user interface (120; 220) may be configured to receive input from the user via touching or swiping a touch screen, typing on a keypad or keyboard, speaking into a microphone, making gestures detected by a camera, making gestures detected by a gyroscope, or other or any combination of the foregoing.

[0072] The control circuit 230 may be similar to the control circuit 130, and the processing circuit 240 may be similar to the processing circuit 140. The processing circuit 240 may use suitable techniques or combinations of techniques to calculate the eye refractive error, the power and addition of the reading glasses, based on the distance measurement value between the user's head or a part thereof 270 and the electronic device 200 measured by the distance measurement circuit 210 and the user input obtained from the user interface 220 (both set by signals from the control circuit 230).

[0073] For example, the control circuit 230 may configure the user interface 220 to instruct the user to slowly bring the electronic device 200 near the user's head 270 until the touch screen 220 can just barely be seen due to its proximity to the head (corresponding to a near boundary of the clear vision range). Additionally, the control circuit 230 may instruct the user (or another person) to touch the touch screen 220 to indicate the aforementioned distance. Then the processing circuit 240 may use this user input and the current measurement of the distance between the user's head 270 and the electronic device 200 obtained from the distance measurement circuit 210 to measure dNP and pNP. As another example, the user interface 220 may instruct the user to slowly move the electronic device 220 away from the user's head 270 until the touch screen 220 can just barely be seen due to its distance from the head (corresponding to a far boundary of the clear vision range). Additionally, the control circuit 230 may instruct the user to touch the touch screen 220 to indicate the aforementioned distance. Then the processing circuit 240 may use this user input and the current measurement of the distance between the user's head 270 and the electronic device 200 obtained from the distance measurement circuit 210 to measure dPF and pFP. Additionally, the processing circuit 240 may use any suitable technique or combination of techniques to calculate BICV and additional information such as the user's age, gender, the eye to be tested, or other or any combination of the foregoing.

[0074] In some embodiments, the processing circuit 240 may automatically detect the age, gender, or eye to be tested of a user from an image of the user's head 270 from a camera in the distance measurement circuit 210. In some embodiments, the processing circuit 240 may obtain the age and gender of the user by sending a signal to the control circuit 230 to set the touch screen in the user interface 220 to prompt the user to input their age, gender, eye to be tested, or any combination of the foregoing or others.

[0075] In some embodiments of the present invention, the control circuit 230 may set the touch screen in the user interface 220 to display a target to assist the user in placing the electronic device 200 at any one of the BICVs.

[0076] Figure 3 FIG. 7 is an exemplary view of an exemplary screen of an electronic device for interactive measurement of eye refractive error and reading glasses addition power and degree, which is based on an embodiment of the present invention, in which a target is displayed on a touch screen included in the user interface.

[0077] The electronic device 300 may be substantially similar to the device 100 shown in Figure 1 and the device 200 shown in Figure 2 and have the same component descriptions as either or both of them. For example, the electronic device 300 may include a camera in the distance measurement circuit 310 and a touch screen in the user interface 320. In some embodiments, the touch screen included in the user interface 320 may be set to display a target 330 to the user, including but not limited to the following types of targets: a visual target 330a, text 330b, geometric patterns 330c, d, a gray scale discrimination test 330e, a color discrimination test 330f, a spatial geometry test 330g, or a picture or video 330h or any combination of the foregoing.

[0078] In some embodiments, the target 330 may be set to change its characteristics according to the measured distance between the user's head 270 and the electronic device 300. For example, the target 300 may be set to change its size, shape, rotation, color, background color, or other characteristics or any combination of the foregoing as the distance between the user's head 270 and the electronic device 300 changes.

[0079] In some embodiments, the target 330 can be set to change its characteristics according to user input from the user interface 320. For example, the target 330 can be set to change its size, shape, rotation, color, background color, or other characteristics, or any combination of the foregoing, according to the interaction between the user and the electronic device 300 by using the touch screen 320 (such as swiping, tapping, clicking, voice commands, or other gestures, or any combination of the foregoing). In addition, in some embodiments, the interaction between the user and the user interface 320 can be implemented by a keypad, a keyboard, a mouse, a microphone, or any other interface method, or any combination of the foregoing.

[0080] Figure 4 FIG. 4 is a flowchart of an exemplary subroutine 400 for changing a target as a function of the distance between a head and an electronic device, based on one embodiment of the present invention. The subroutine 400 can include several steps. In some embodiments, the order of the steps of the subroutine 400 can be changed, or some steps can be omitted or repeated. In addition, the subroutine 400 can be incorporated as a subroutine into another program (parent program).

[0081] The subroutine 400 can be implemented by an electronic device (100; 200; 300) with a distance measurement circuit (110; 210; 310) and a user interface (120; 220; 320), and one or more other components of the electronic device (100; 200; 300).

[0082] The first step of the subroutine 400 can continue from the parent program and begin at block 410, where the user interface (120; 220; 320) can be set to display a target 330 on the screen 320. For example, in one embodiment of the present invention, the foregoing target can be a visual target 330a, or text 330b, or one or more parallel lines 330c, d, or one or more gray blocks 330e, or color blocks 330f, or a geometric pattern such as 330g, or a picture 330h, or other types of targets, or any combination of the foregoing.

[0083] At block 420, the user can change the distance between the user's head 270 and the electronic device (100; 200; 300). In addition, the distance measurement circuit (110; 210; 310) can send a signal to the processing circuit (140; 240), the signal including a measurement of the distance between the user's head 270 and the electronic device (100; 200; 300). As described above, the distance measurement circuit (110; 210; 310) can use any suitable technique or combination of techniques to measure the distance between the user's head 270 and the electronic device. In addition, the distance between the foregoing user's head and the device can be measured using another method (such as a ruler or a rangefinder) and input into the user interface (120; 220; 320).

[0084] In some embodiments of the present invention, changing the distance between the user's head 270 and the electronic device may include having the user hold the device and bring it closer to or farther from the face.

[0085] In some embodiments of the present invention, changing the distance between the user's head 270 and the electronic device may include placing a reflective surface (such as a mirror) in front of the electronic device (so that the mirror image of the user's head 270 is within the field of view of the electronic device), and changing the distance between the device and the mirror, or changing the distance between the user's head or a part thereof 270 and the mirror, or any combination of the foregoing.

[0086] In some embodiments of the present invention, changing the distance between the user's head 270 and the electronic device may include having a third party (such as another person, another instrument, or any combination of the foregoing) change the distance.

[0087] In block 430, the user interface may be set to change the characteristics of the target 330. For example, in one embodiment of the present invention, the distance measurement circuit (110; 210; 310) may send a signal to the processing circuit (140; 240), the signal including a measured value of the distance between the user's head 270 and the electronic device (100; 200; 300). The processing circuit may process the foregoing signal using any technique or combination of techniques and send a signal to the control circuit (130; 230), which in turn may set the user interface (120; 220; 320) to change the characteristics of the target 330 according to the distance between the user's head and the electronic device, such as size, shape, rotation, color, background color, or other characteristics, or any combination of the foregoing. Block 440 may be a decision block, where the user interface (120; 220; 320) may be set to instruct the user to evaluate whether the target 330 meets a certain visual quality standard. For example, in one embodiment of the present invention, the visual quality standard may be a visual acuity standard (such as being able to see a visual target (330a) or text (330b), or see two or more parallel lines (330c, d)), or others, or any combination of the foregoing. Again, in one embodiment of the present invention, the visual quality standard may be a contrast sensitivity standard (such as being able to distinguish a gray block (330e) or match a gray block), or a color discrimination standard (such as being able to distinguish a color (330f) or match a color), or a spatial geometry standard (such as being able to detect a deformation of a geometric pattern (330g), such as warping of a grid), or recognize a picture or details in a picture, or other standards, or any combination of the foregoing.

[0088] In addition, in decision block 450, if the user inputs to the user interface (120; 220; 320) indicating that the target 330 meets a certain visual quality standard, then the subroutine 400 may proceed to block 440.

[0089] On the other hand, at decision block 450, if the user inputs to the user interface (120; 220; 320) indicating that the target 330 does not meet a certain visual quality standard, subroutine 400 can go to block 460 (which can be a decision block). At block 450 (which can be a decision block), if the distance between the user's head 270 and the electronic device can be further changed, subroutine 400 can return to block 420. On the other hand, at block 450, if the distance cannot be further changed (such as the user cannot hold the electronic device farther away than arm's length), subroutine 400 can proceed to block 450.

[0090] At block 440, the distance between the user's head 270 and the electronic device (100; 200; 300) can be stored in the memory (150; 250) together with (but not limited to) the user input data. In addition, at block 440, subroutine 400 can return to the parent program that contains the subroutine.

[0091] Figure 5 FIG. 9 is a flowchart of an exemplary program 500 for interactive measurement of eye refractive error and reading glasses addition power and degree, based on an embodiment of the present invention. Program 500 can include multiple steps. In some embodiments, the order of the steps of program 500 can be changed or some steps can be omitted or repeated.

[0092] Program 500 can be implemented by an electronic device (100; 200; 300) with a distance measurement circuit (110; 210; 310) and a user interface (120; 220; 320), as well as one or more other components of the electronic device (100; 200; 300).

[0093] Program 500 can start at block 510, where the user interface (120; 220; 320) of the electronic device (100; 200; 300) can be set to receive user input information (such as age, gender, values of spherical and cylindrical powers of spectacle lenses or contact lenses input by the subject, vertex distance, or any combination of the foregoing or others). For example, in an embodiment of the present invention, the foregoing information can be obtained by setting the user interface (120; 220; 320) to prompt the user to input the foregoing information into the user interface using a touch screen or a voice recognition circuit or any combination of the foregoing or others. Again, for example, in an embodiment of the present invention, the foregoing information can be automatically obtained by detecting an image of the user's head 270 from a camera included in the foregoing user interface.

[0094] At block 520, the user interface (120; 220; 320) can be set to indicate that the user use one (left or right) eye or both eyes when interacting with the electronic device (100; 200; 300).

[0095] At block 530, program 500 can include subroutine 400 (see Figure 4 ). For example, in one embodiment of the present invention, at decision block 430 of subroutine 400 included in block 520 of program 500, the user can provide user input to the user interface (120; 220; 320) indicating that a certain criterion (corresponding to the electronic device (100; 200; 300) placed at or near the far or near boundary of the BICV) has been met for target 330. At block 440 of subroutine 400 included in block 530 of program 500 (see Figure 4 ), the distance between the electronic device (100; 200; 300) and the subject's head 270 can be stored in the memory (150; 250).

[0096] At block 540, the user interface (120; 220; 320) can be set to display a new target and indicate that the user select a preferred target direction angle when interacting with the electronic device (100; 200; 300). For example, in one embodiment of the present invention, the user interface (120; 220; 320) of the electronic device (100; 200; 300) placed near the dFP (or pNP) can be set to receive user input (including the preferred target direction angle αdFP (or αpNP)). In one embodiment of the present invention, the user interface (120; 220; 320) can be set to change target 330 on the touch screen 320 in response to user input (such as touching or swiping the touch screen, or typing on a keypad or keyboard, speaking into a microphone, making a gesture detected by a camera, making a gesture detected by a gyroscope, or any combination of the foregoing). Again, for example, in one embodiment of the present invention, the user interface (120; 220; 320) is set to display target 330 (including but not limited to a set of parallel lines on the touch screen 320) and receive user input from the touch screen 320 and change the direction of the target 330 by the angle αdFP or (αpNP). At block 550, the preferred target direction angle αdFP selected by the user at block 540 can be stored in the memory (150; 250).

[0097] At block 560, program 500 can include subroutine 400 (see Figure 4)。At block 410, the user interface (120; 220; 320) can be set to display a new target (including but not limited to a set of parallel lines oriented at an angle αdFP or (αpNP) on the touch screen 320). At decision block 430 of subroutine 400 contained in block 560 of program 500, the user can provide user input to the user interface (120; 220; 320) indicating that the visual quality of the aforementioned target 330 has reached a certain specific standard (corresponding to the electronic device (100; 200; 300) placed at dFP (or pNP) or nearby). At block 440 of subroutine 400, dFP (or pNP) can be saved in the memory (150; 250).

[0098] At block 570, program 500 can include subroutine 400 (see Figure 4 )。At block 410, the user interface (120; 220; 320) can be set to display a new target (including but not limited to a set of parallel lines oriented at an angle αpFP = αdFP + 90° (or αdNP = αpNP - 90°) on the touch screen 320). At decision block 430 of subroutine 400 contained in block 570 of program 500, the user can provide user input to the user interface (120; 220; 320) indicating that the visual quality of the aforementioned target 330 has reached a certain specific standard (corresponding to the electronic device (100; 200; 300) placed at pFP (or dNP) or nearby). At block 440 of subroutine 400, pFP (or dNP) can be saved in the memory (150; 250).

[0099] At block 580, the processing circuit (140; 240) can calculate the eye refractive error using any technique or combination of techniques from dFP, pFP, αdFP, αpFP, dNP, pNP, αdNP, or αpNP or any combination of the foregoing or others, such as but not limited to sphere (SPH), cylinder (CYL), and axis (AXS). In one embodiment of the present invention, AXS can be calculated from αdFP and αpFP using, for example, the following equations:

[0100] AXS = 90° - αpFP when 0° < αdFP < 90°; or

[0101] AXS = 270° - αdFP otherwise; Equation 1

[0102] and αdFP = αpFP - 90°. Equation 2

[0103] In addition, AXS can be calculated from αdNP and αpNP using, for example, the following equations:

[0104] AXS = 90° - αdNP when αdNP < 90°; or

[0105] AXS = 270° - αdNP other; Equation 3

[0106] And αdNP = αpNP - 90°. Equation 4

[0107] Here, αdNP, αpNP, αdFP, and αpFP are expressed in degrees (from 1° to 180°).

[0108] SPH and CYL can be calculated from dFP and pFP using, for example, the following equations:

[0109] SPH = -1 / dFP + K. Equation 5

[0110] CYL = -(1 / pFP - 1 / dFP), Equation 6

[0111] Here, the parameter K depends on the target and background colors. For a black background, the K values for white, blue, and red targets are K = 0D, K > 0D, and K < 0D, respectively; the specific value of K depends on the emission spectrum of the physical target.

[0112] In an embodiment of the present invention, SPH and CYL can be calculated from dFP and pFP using, for example, the following equations:

[0113] SPH = AA - 1 / dNP + K. Equation 7

[0114] CYL = -(1 / pNP - 1 / dNP), Equation 8

[0115] Here, the AA value depends on age, such as:

[0116] AA = 15.6 - 0.3 * age, when age <= 52 years; or

[0117] AA = 0D other. Equation 9 The values of dFP, pFP, dNP, and pNP can be expressed in meters and diopters K. Age can be expressed in years.

[0118] In addition, at block 580, the processing circuit (140; 240) can calculate the power (P) of the reading glasses from dNP or pNP or other parameters or any combination of the foregoing using any technique or combination of techniques. For example, in an embodiment of the present invention, the power P of the reading glasses can be calculated as follows:

[0119] P = 3D - E(1 / ((dNP + pNP) / 2) + K), when E(1 / ((dNP + pNP) / 2) + K) < 3D

[0120] P = 0D other. Equation 10

[0121] Here, P can be expressed in diopters, and E can be a constant value between 0 and 1.

[0122] As described above, at block 520 of program 500, the user interface (120; 220; 320) can be set to indicate whether the user should use one (left or right) eye or both eyes when interacting with the electronic device (100; 200; 300). For example, in one embodiment of the present invention, at block 410 of subroutine 400 included in block 530 of program 500 (see Figure 4 ), the user interface (120; 220; 320) can be set to display a target 330 (including but not limited to text (330b)). At block 440 of subroutine 400, the near point distance NP can be stored in the memory (150; 250), and the power P of the reading glasses can be calculated as follows:

[0123] P = 3D – E(1 / NP + K), when E(1 / NP + K) < 3D

[0124] P = 0D otherwise. Equation 11

[0125] Here, NP can be expressed in meters.

[0126] In one embodiment of the present invention, the add power (ADD) of the reading glasses can be calculated using the following equation:

[0127] ADD = P - (SPH + CYL / 2) when P > (SPH + CYL / 2); or

[0128] ADD = 0D otherwise. Equation 12

[0129] Equations 1 - 12 correspond to corneal surface refraction.

[0130] Furthermore, at block 580 of program 500, the processing circuitry (140; 240) included in the electronic device (100; 200; 300) can calculate the spectacle plane refraction or the power of the reading glasses using any suitable technique or combination of techniques from the corneal surface refraction of dFP, pFP, dNP, pNP, FP, NP, vertex distance (VD), or any other or combination of the foregoing. VD depends on the type of correction (usually 0.00m for contact lenses and 0.014m for ordinary glasses).

[0131] At block 590, parameters (such as but not limited to SPH, CYL, AXS, FP, NP, P, ADD, dFP, pFP, αdFP, αpFP, dNP, pNP, αdNP, αpNP, VD), user input, or any other or combination of the foregoing can be stored in the memory (150; 250).

Claims

1. A computer-implemented method for interactively measuring the eye refractive error, addition power, and reading glasses power of a user of an electronic device (100; 200; 300), comprising: · Displaying a target (330) on an electronic screen (320) of the electronic device (100; 200; 300), · Receiving a first input from the user and changing the spatial characteristics of the target (330) according to the user input, · Receiving a second input from the user, the second input indicating that the electronic screen (320) of the electronic device (100; 200; 300) is at one of the boundaries BICV of the clear vision interval, and at the boundary BICV of the clear vision interval, the visual quality of the target (330) reaches a certain visual quality standard, wherein the certain visual quality standard is a contrast sensitivity standard, a color resolution standard, subjective clarity, or any combination thereof; · Using the second input to at least measure the distance between the user's head (270) or a part of the user's head and the electronic screen; · Calculating at least one refractive parameter selected from a first group of cylinder CYL, axis AXS, and reading glasses power P at least from the measured distance; or calculating at least one refractive parameter selected from a second group of sphere SPH and addition power ADD at least from the measured distance and the user's age AGE.

2. The computer-implemented method of claim 1, wherein displaying a target (330) on the electronic screen (320) of the electronic device (100; 200; 300) includes changing the characteristics of the size, direction, position, or color of the target independently of each other as the distance between the user and the electronic device changes.

3. The computer-implemented method based on claim 1, wherein the target (330) on the electronic screen (320) of the electronic device (100; 200; 300) includes: · A single letter, a single visual target, a group of letters, or a group of visual targets (330a), · A text (330b), · A geometric pattern (330c, d), · A color or grayscale block (330e, f), · A repeating pattern, · A picture or video (330h), and · Other spatial stimuli or any combination of the above.

4. The computer-implemented method based on claim 3, wherein the repeating pattern includes a grid (330g).

5. The computer-implemented method based on claim 1, wherein changing the characteristics of the target (330) according to the user input includes rotation, translation, size change, shape change, color change, or any combination of the foregoing or others.

6. The computer-implemented method based on claim 1, further comprising: · Interactively changing the rotation of the target (330) on the electronic screen (320) by the user to a target direction angle at which the visual quality of the target image can reach a certain visual quality standard that the user prefers; · Measuring a first distance between the electronic screen (320) and the user's head (270) or a part thereof; · Changing the target (330) such that at least one line of the target is perpendicular to the foregoing preferred target direction angle and measuring a second distance between the electronic screen and the user's head; · Calculate at least one refractive parameter from the first distance, the second distance, the preferred angle of the target direction, the user's age, the spectral color characteristics of the target, or other parameters, or any combination of the foregoing.

7. The computer-implemented method according to claim 1 or 6, wherein the preferred target direction angle is found by physically rotating the screen or a stimulus on the screen (320) of the electronic device (100; 200; 300) around the user's line of sight.

8. The computer-implemented method according to claim 1 or 6, wherein the preferred target direction angle is calculated from an image of the user's head (270) or a part thereof that can be rotated relative to the screen (320) of the electronic device (100; 200; 300).

9. The computer-implemented method according to claim 6, wherein the first distance is calculated from a mathematical relationship between the user's age and the second distance.

10. The computer-implemented method according to any one of claims 1-6, wherein a reflective surface is placed between the eyes of the user's head or a part of the user's head (270) and the screen (320) of the electronic device (100; 200; 300) to change the optical path of the light from the target to the user's eyes.

11. The computer-implemented method according to any one of claims 1-6, wherein at least one refractive parameter is recalculated from the refractive parameter and the vertex distance (VD) between the corneal surface and the spectacle plane.

12. The computer-implemented method according to claim 1, wherein the user's age (AGE) is obtained by one of the following methods: · Enter the AGE or birthday of the user or remotely from the database input user interface (120; 220) of the electronic device (100; 200; 300); · Detect the AGE from an image of the user's head or a part of the user's head using an age detection algorithm; · Or any combination of the foregoing.

13. A system incorporated in an electronic device (100; 200; 300) for a user to interactively measure the refractive error of the user's eyes and the power and add power of a reading glass, comprising: · A distance measurement circuit (110; 210) configured to measure the distance between the user's head (270) or a part of the user's head and the electronic screen (320) of the electronic device (100; 200; 300) based on user input; · A user interface (120; 220) configured to give instructions to the user and receive user input; · An electronic screen (320) for displaying and changing the target; · A processing circuit (140; 240) configured to calculate at least one refractive parameter; · A memory (150; 250) configured to store the at least one refractive parameter in the memory of the electronic device (100; 200; 300); · Wherein the user input for the distance measurement circuit indicates that the electronic screen of the electronic device is at one of the boundaries of the clear vision interval BICV, and at the boundary of the clear vision interval BICV, the visual quality of the target reaches a certain visual quality standard, · Wherein the certain visual quality standard is a contrast sensitivity standard, a color resolution standard, subjective clarity, or any combination thereof; · Wherein, the calculated at least one refractive parameter is selected from a first group including at least the measured distance, cylinder CYL, axis AXS, and the power P of the reading glasses; or is selected from a second group including at least the measured distance and the addition ADD selected by the user's age AGE and sphere SPH.

14. The system according to claim 13, wherein the distance measurement circuit (110; 210) and the user interface (120; 220) of the electronic device (100; 200; 300) are further configured to: · Measure the rotation of the device relative to an axis; · Measure the rotation or tilt of the user's head (270) or a part thereof relative to the foregoing axis.

15. The system according to any one of claims 13-14, wherein the user interface (120; 220) further comprises: · A speaker; · A microphone; · A voice recognition circuit; · Or any combination of the foregoing.

16. The system according to claim 13, further comprising a communication circuit (160; 260), configured to transmit the at least one refractive parameter to and from a network.

17. The system according to claim 14, wherein, This axis is the line of sight between the user and the electronic device.

18. An apparatus including the system according to any one of claims 13-16, wherein the apparatus is: · A mobile phone; · A tablet; · A smart TV; · A personal digital assistant; · A laptop computer; · A desktop computer; · A stand-alone camera; · A game controller; or · A video recorder.

19. A computer program product storing computer-readable instructions that, when executed by a processor of a device (100; 200; 300), cause the processor to perform the method according to any one of claims 1-12.

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