Ophthalmic lenses with light scattering properties for treating myopia

Abstract

To provide a method comprising forming on an ophthalmic lens a plurality of spaced apart scattering centers sized and shaped to scatter light incident on the ophthalmic lens.SOLUTION: An ophthalmic lens is provided, comprising a lens material having two opposing curved surfaces defining a lens axis, and a light scattering region surrounding a clear aperture. The clear aperture and the light scattering region are substantially centered on the lens axis, and the light scattering region has a plurality of spaced apart scattering centers (e.g., on a lens surface and / or embedded in the lens material) sized and shaped to scatter incident light, the scattering centers being arranged in a pattern including a random variation in spacing between adjacent dots and / or a random variation in dot size.SELECTED DRAWING: None

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority to Provisional Application No. 62 / 624,038, titled "METHODS FOR FORMING OPHTHALMIC LENSES FOR TREATING MYOPIA," filed on 30 January 2018; Provisional Application No. 62 / 663,938, titled "OPHTHALMIC LENSES WITH LIGHT SCATTERING FOR TREATING MYOPIA," filed on 27 April 2018; and Provisional Application No. 62 / 671,992, titled "OPHTHALMIC LENSES WITH LIGHT SCATTERING FOR TREATING MYOPIA," filed on 15 May 2018. The entire contents of each of these Provisional Applications are incorporated herein by reference.

[0002] The present invention features an ophthalmic lens for treating myopia and slowing its progression. [Background technology]

[0003] The eye is an optical sensor in which light from an external source is focused by a lens onto the surface of the retina, which is an array of wavelength-dependent photosensors. Each of the various shapes that the eye's lens can employ relates to the focal length at which external rays are optimally or nearly optimally focused to produce an inverted image on the surface of the retina corresponding to the external image observed by the eye. In each of the various shapes that the eye's lens can employ, the eye's lens optimally or nearly optimally focuses on light emitted or reflected by external objects within a certain range of distance from the eye, and suboptimally focuses on or fails to focus on objects outside that range.

[0004] In a person with normal vision, the axial length of the eye, or the distance from the lens to the surface of the retina, corresponds to a focal length close to the optimal focus for distant objects. A person with normal vision focuses on distant objects without the need for nerve input to the muscles that apply force to change the shape of the eye's lens in a process called "accommodation." Closer objects are focused on by a person with normal vision as a result of accommodation.

[0005] However, many people suffer from vision disorders related to the length of the eye, such as myopia (nearsightedness). In people with myopia, the axial length of the eye is longer than the axial length required to focus on a distant object without accommodation. As a result, people with myopia can see nearby objects clearly, but objects further away appear blurry. While people with myopia can generally accommodate, the average distance at which they can focus on an object is shorter than that of people with normal vision.

[0006] Typically, infants are born farsighted, with the length of the eye shorter than necessary for optimal or near-optimal focus on distant objects without accommodation. During a period of normal eye development called "emmetropia," the axial length of the eye grows to a length that, relative to other dimensions of the eye, allows for near-optimal focus on distant objects without accommodation. Ideally, the biological process maintains a near-optimal relative length of the eye as it grows to its final adult size. However, in myopic individuals, the axial length of the eye relative to the overall eye size continues to increase during development beyond the length that would allow for near-optimal focus on distant objects, resulting in increasingly pronounced myopia.

[0007] Myopia is believed to be influenced by both behavioral and genetic factors. Therefore, myopia can be reduced by therapeutic devices that address behavioral factors. For example, a therapeutic device for treating eye length-related disorders, including myopia, is described in U.S. Patent Application Publication 2011 / 0313058A1. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] U.S. Patent Application Publication No. 2011 / 0313058 A1 [Patent Document 2] International Patent Application No. PCT / US2017 / 044635 [Non-Patent Document]

[0009] [Non-Patent Document 1] International Test Standard ASTM D1003 [Non-Patent Document 2] International Test Standard BS EN ISO 13468 [Non-Patent Document 3] Internet <http: / / www.montana.edu / jshaw / documents / 18%20EELE582_S15_OTFMTF.pdf> [Non-Patent Document 4] Internet <https: / / www.slrlounge.com / diffraction-aperture-and-starburst-effects / > [Summary of the Invention] [Means for Solving the Problems]

[0010] Glasses and contact lenses that reduce signals in the retina responsible for elongation of the eye length are disclosed. Exemplary embodiments are made using, for example, polycarbonate, or Trivex lens blanks, processed by adding a pattern of scattering centers or “dots” having an aperture without dots on the visual axis. As a result, the contrast in the retinal image that is believed to reduce the elongation of the eye associated with the progression of myopia is reduced. With an aperture without dots disposed on the lens axis, the user experiences the highest visual acuity when viewing an object on the axis, while objects in the periphery of the user's field of view appear with reduced contrast and clarity.

[0011] In these glasses, the focused image has a reduced contrast in the peripheral region of the retina compared to what is normally used to correct (but not treat) refractive errors. The exact amount of contrast reduction depends on the relative amounts of dark and bright regions in the transmitted image. In the example above, 24% of the light is evenly distributed, but the maximum contrast reduction is 48%. Here, contrast is defined as the luminance difference / average luminance. Experiments have shown that such a reduction in contrast in the peripheral region of the retina has an important impact on the eye's physiology related to the mechanism responsible for controlling the elongation of the eye's length.

[0012] Various aspects of the present invention are summarized as follows.

[0013] Generally, in a first aspect, the present invention features an ophthalmic lens comprising a lens material having two opposing curved surfaces and a scattering region surrounding a transparent aperture, the scattering region having a plurality of spaced-apart scattering centers sized and shaped to scatter incident light, the scattering centers being arranged in a pattern including an irregular variation in the spacing between adjacent scattering centers and / or an irregular variation in the size of the scattering centers.

[0014] Embodiments of the ophthalmic lens can include one or more of the following features and / or features of other aspects. For example, the scattering centers can be positioned relative to the lattice sites of a regular array, where each scattering center is displaced from the corresponding one of the lattice sites by an amount equal to or less than the jitter amplitude in at least one dimension (e.g., the x direction and / or the y direction), and the jitter amplitude is a fraction of the distance between adjacent lattice sites. The jitter amplitude can be 0.5 or less (e.g., 0.01 - 0.5, 0.02 or more, 0.03 or more, 0.04 or more, 0.05 or more, 0.08 or more, 0.1 or more, 0.12 or more, 0.15 or more, 0.18 or more, 0.2 or more, 0.25 or more, 0.3 or more, 0.35 or more, 0.4 or more).

[0015] The scattering center may have dimensions that vary randomly from the rated value, and the random variation is equal to or less than the jitter amplitude. The jitter amplitude may be 0.5 times or less of the rated value (for example, 0.01 to 0.5, 0.02 or more, 0.03 or more, 0.04 or more, 0.05 or more, 0.08 or more, 0.1 or more, 0.12 or more, 0.15 or more, 0.18 or more, 0.2 or more, 0.25 or more, 0.3 or more, 0.35 or more, 0.4 or more).

[0016] The scattering center may have a volume that varies randomly from the rated volume, and the random variation is equal to or less than the jitter amplitude. The jitter amplitude multiplied by the rated volume may be 0.5 or less (for example, 0.01 to 0.5, 0.02 or more, 0.03 or more, 0.04 or more, 0.05 or more, 0.08 or more, 0.1 or more, 0.12 or more, 0.15 or more, 0.18 or more, 0.2 or more, 0.25 or more, 0.3 or more, 0.35 or more, 0.4 or more).

[0017] The lens may have a lens axis, and the aperture and annular region may be approximately centered on the lens axis.

[0018] The scattering region may include a first scattering area and a second scattering area located between a transparent aperture and the first scattering area, the second scattering area having a scattering center sized and positioned to scatter incident light more weakly than the scattering center of the first scattering area. The lens may have a lens axis, the aperture and the first and second scattering areas are approximately centered on the lens axis, and the scattering center in the second scattering area has dimensions that increase monotonically (e.g., linearly or geometrically) as the radial distance from the lens axis increases. The lens may have a lens axis, the aperture and the first and second scattering areas are approximately centered on the lens axis, and the scattering center in the second scattering area has dimensions and / or volume that change monotonically (e.g., linearly or geometrically) as the radial distance from the lens axis increases.

[0019] Irregular changes in the spacing between scattering centers may be random. Irregular changes in the size of scattering centers may also be random.

[0020] The scattering center spacing and / or scattering center size can be varied to encode information into the scattering centers.

[0021] The scattering center may be approximately circular in shape. The scattering center can also be shaped like a logo or alphanumeric code.

[0022] The lens may be a flat lens, a single-vision lens, or a multifocal lens. The lens may be an eyeglass lens or a contact lens.

[0023] The scattering region may be an annular region. The transparent aperture may be a circular aperture.

[0024] In another embodiment, the present invention is a method for treating an eye-length disorder, comprising the steps of identifying an eye-length disorder in a patient and reducing the contrast of peripheral images in the patient's vision using an ophthalmic lens according to a previous embodiment.

[0025] In a further embodiment, the present invention features a pair of eyeglasses comprising an eyeglass frame and a pair of ophthalmic lenses, each attached to the frame, according to the above embodiment.

[0026] Embodiments of eyeglasses may include one or more of the following features and / or features of other embodiments. For example, the dot pattern can reduce the image contrast of an object viewed through the dot pattern by at least 30% (e.g., at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, and up to 80%) compared to the image contrast of the object viewed through a clear aperture.

[0027] The lens can have a refractive power that corrects the wearer's axial vision to 20 / 20 or better through a transparent aperture, and corrects the wearer's vision to 20 / 25 or better in at least a portion of the wearer's peripheral vision through the dot pattern.

[0028] In another aspect, the present invention is a method for treating an eye-length disorder, comprising the steps of identifying an eye-length disorder in a patient and reducing the contrast of peripheral images in the patient's vision using the above-mentioned eyeglasses.

[0029] In general, in yet another embodiment, the present invention features a method comprising the steps of focusing a laser beam to a focal point and exposing an ophthalmic lens to the focused laser radiation in order to form optical scattering features in a pattern on the curved surface of the ophthalmic lens. The step of exposing the ophthalmic lens includes causing relative motion between the laser beam and the lens such that different locations on the lens surface intersect the laser beam at different locations relative to the focal point.

[0030] Implementations of the method may include one or more of the following features and / or features of other embodiments: For example, the optical scattering features formed by the laser beam can be varied depending on the location of the lens surface relative to the focal point. The degree of scattering due to the optical scattering features can be reduced as the distance of the lens surface relative to the focal point increases.

[0031] The pattern may include an annular region of optical scattering features surrounding a transparent aperture corresponding to the visual axis of the ophthalmic lens. The optical scattering features may include separate dots. The dots may be arranged in an array, spaced at a distance of 1 mm or less from each other, with each dot having a maximum dimension of 0.5 mm or less. The transparent aperture may be a dot-free area with a maximum dimension greater than 1 mm.

[0032] The laser may be an infrared laser. The laser may be a CO2 laser.

[0033] Ophthalmic lenses can be exposed to pulsed laser radiation.

[0034] A laser can have enough energy to remove lens material from the surface of a lens.

[0035] Lasers can have power ranging from 0.5W to 60W.

[0036] The laser radiation can be focused to a spot size of approximately 0.1 mm or less (for example, approximately 0.05 mm or less, approximately 0.025 mm or less) during the exposure period.

[0037] An ophthalmic lens can be exposed such that each location on the lens surface receives a corresponding separate exposure of the same duration and energy.

[0038] The exposure surface may be convex or concave.

[0039] In general, in further embodiments, the present invention features a method for forming scattering centers in an ophthalmic lens, comprising the step of exposing an area of ​​the ophthalmic lens to laser radiation having a wavelength and power sufficient to foam the material forming the ophthalmic lens. Bubbles from the foam form scattering centers in the ophthalmic lens. Implementations of the method may include one or more features of other embodiments.

[0040] In general, in yet another aspect, the present invention features a method comprising the steps of simultaneously exposing an ophthalmic lens formed from a lens material to two or more beams of laser radiation such that the two or more beams of laser radiation overlap in a portion of the lens material, wherein the intensity of the laser radiation in the overlapping beams is sufficient to form optical scattering features in the lens material, and the steps of changing the position of the overlapping beams in the lens to form a pattern of optical scattering features in the lens.

[0041] Implementations of the method may include one or more of the following features and / or features of other embodiments. For example, the intensity of a single laser among two or more beams may be insufficient to form optical scattering features in the lens material with an exposure of less than 10 seconds to the laser beam.

[0042] The laser radiation from overlapping beams interacts with the lens material, changing its refractive index.

[0043] The laser radiation from overlapping beams can cause photochemical changes in the lens material, thereby altering the refractive index of the lens material.

[0044] The laser radiation from overlapping beams can alter the refractive index of a lens material by causing photothermal changes within the material.

[0045] In another embodiment, the present invention features a pair of eyeglasses comprising an eyeglass frame and a pair of ophthalmic lenses mounted on the frame, wherein each lens includes a pattern dispersed over each lens formed using one of the above methods.

[0046] Embodiments of the glasses may include one or more of the following features and / or features of other embodiments. For example, each pattern may include an area containing optical scattering features surrounding a transparent aperture without scattering features. The dot pattern may reduce the image contrast of an object viewed through the dot pattern by at least 30% (e.g., at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%) compared to the image contrast of the object viewed through the transparent aperture.

[0047] The lens can have a refractive power that corrects the wearer's axial vision to 20 / 20 or better through a transparent aperture, and corrects the wearer's peripheral vision to 20 / 25 or better in at least a portion of the wearer's peripheral vision through a dot pattern.

[0048] Among the advantages, the disclosed embodiments feature eyeglasses that include a feature that reduces the signals in the retina responsible for extending the length of the eye for both lenses without reducing the on-axial vision of either eye to a degree that confuses the user. For example, by providing a dot pattern that allows normal on-axial vision through a clear aperture while subtly blurring the wearer's peripheral vision, the eyeglasses can be worn by the wearer all day, every day. The disclosed embodiments can also provide therapeutic benefits to the user using only a single pair of eyeglasses for both eyes, as opposed to methods that involve using different pairs of eyeglasses alternately or using eyeglass accessories.

[0049] Furthermore, the dot pattern can be almost unnoticeable to others, especially if the dot pattern is transparent and colorless, and / or when contact lenses are used. The inconspicuousness of the dot pattern may result in more consistent use by certain wearers, particularly children, who might feel embarrassed using more noticeable devices daily (e.g., at school or among peers). For example, a graduated dot pattern can be used to reduce the visibility of the dot pattern to third parties.

[0050] Dot patterns can also be optimized for viewer comfort. For example, a dot pattern may feature transition zones that soften the transition from the clear aperture of the lens to the scattering zone within the viewer's field of view. Alternatively or additionally, random jitter can be added to the dot pattern (e.g., to the dot size and / or dot spacing). Such randomization can reduce unwanted optical effects (e.g., diffraction or interference effects) associated with a uniform arrangement of optical features. For example, random jitter can be used to reduce the glare experienced by the user. The dot pattern may also be less noticeable to a third party by reducing diffraction or interference effects during reflection.

[0051] Information can be encoded into a dot pattern. For example, the dots can be shaped like a code (e.g., an alphanumeric code) or a logo. Alternatively or additionally, the dot shape, size, and / or spacing can be varied according to a key used to embed information in the dot pattern.

[0052] The disclosed embodiments may enable the effective and economical formation of a dot pattern on a conventional ophthalmic lens to reduce eye lengthening, for example, by forming the dot pattern on the surface of the lens or within the lens bulk. [Brief explanation of the drawing]

[0053] [Figure 1A] This is a diagram showing a pair of eyeglasses containing ophthalmic lenses for treating nearsightedness. [Figure 1B] This figure shows the dot pattern on an ophthalmic lens, as shown in Figure 1A. [Figure 2] This figure illustrates contrast reduction experienced when using an exemplary ophthalmic lens for treating myopia. [Figure 3A] This is a cross-sectional view showing exemplary lens material removed from the surface of a lens. [Figure 3B] This is a cross-sectional view showing an exemplary lens having a scattering inclusion between opposing surfaces of the lens. [Figure 4A] This figure shows a lens blank having a dot pattern with a transition zone between a transparent aperture and the dot pattern. [Figure 4B] This figure shows a lens blank having a dot pattern with a transition zone between a transparent aperture and the dot pattern. [Figure 4C] This figure shows dots with random displacements at uniform intervals. [Figure 5A] This figure shows an exemplary dot pattern with transition zones and uniformly spaced dots. [Figure 5B]This figure shows an exemplary dot pattern with transition zones and dots having random displacements from uniform intervals. [Figure 5C] This figure shows another exemplary dot pattern with transition zones and uniformly spaced dots. [Figure 5D] This figure shows a transition zone and another exemplary dot pattern having dots with random displacements from uniform intervals. [Figure 5E] This figure shows a further exemplary dot pattern having transition zones and uniformly spaced dots. [Figure 5F] This figure shows a transition zone and a further exemplary dot pattern having dots with random displacements from uniform intervals. [Figure 6A] This figure shows an exemplary lens having a stepped dot pattern with different spacings between adjacent dots. [Figure 6B] This figure shows an exemplary lens having a stepped dot pattern with varying dot sizes. [Figure 7A] This figure shows an exemplary lens having a pattern in which information is encoded by dots of varying sizes. [Figure 7B] This figure shows an exemplary lens having a pattern containing information encoded by dots of different shapes. [Figure 7C] This figure shows an exemplary lens with a pattern for forming dots in the shape of a logo. [Figure 8] This is a diagram illustrating an exemplary machine reading system. [Figure 9] This is a schematic diagram of a laser system for creating recesses on the surface of a lens. [Figure 10] This is a schematic diagram of another laser system for creating recesses on the surface of a lens. [Figure 11A] This is a plot of the change in refractive index of the lens material versus the laser intensity. [Figure 11B]This is a schematic diagram of a laser system for forming inclusions in the bulk material of an example lens. [Modes for carrying out the invention]

[0054] Referring to Figure 1A, a myopia-reducing eyeglass 100 is disclosed that allows for simultaneous treatment of both eyes without significantly compromising clear vision. Furthermore, the eyeglass is robust and inconspicuous enough that the wearer can engage in the same daily activities without the eyeglass becoming useless or feeling embarrassed about their appearance. This is particularly desirable because eyeglasses are typically used to stop the eyes from becoming longer in children.

[0055] Myopia-reducing eyeglasses 100 consist of a pair of frames 101 and ophthalmic lenses 110a and 110b mounted on the frames. Generally, the ophthalmic lenses may be planar lenses, monofocal lenses (e.g., with positive or negative refractive power), or multifocal lenses (e.g., bifocal lenses or progressive multifocal lenses). The ophthalmic lenses 110a and 110b each have transparent apertures 120a and 120b, respectively, surrounded by contrast-reducing areas 130a and 130b, respectively. The transparent apertures 120a and 120b are positioned to coincide with the wearer's axial viewing position, while the contrast-reducing areas 130a and 130b correspond to the wearer's peripheral vision. Referring again to Figure 1B, the contrast-reducing areas 130a and 130b consist of an array of dots 140 that reduce the contrast of objects in the wearer's peripheral vision by scattering light passing through those areas to the wearer's eye. Generally, the dots 140 can be provided by forming protrusions and / or recesses on one or both surfaces of each lens in areas 130a and 130b, and / or by forming scattering inclusions in the lens material itself in these areas.

[0056] The size and shape of the transparent aperture can be varied. Generally, the transparent aperture provides the wearer with a cone of field of view that can optimally correct the wearer's vision (e.g., to 20 / 15 or 20 / 20). In some embodiments, the aperture has a maximum dimension (in the xy plane) in the range of about 0.2 mm (e.g., about 0.3 mm or more, about 0.4 mm or more, about 0.5 mm or more, about 0.6 mm or more, about 0.7 mm or more, about 0.8 mm or more, about 0.9 mm or more) to about 1.5 cm (e.g., about 1.4 cm or less, about 1.3 cm or less, about 1.2 cm or less, about 1.1 cm or less, about 1 cm or less). Here, the aperture is circular, as depicted in Figure 1A, for example, and this dimension corresponds to the diameter of the circle (i.e., A x =A y ) is non-circular (for example, elliptical, polygonal, A x ≠A y ) Openings are also possible.

[0057] A transparent aperture can define a range of solid angles in the viewer's field of view that is approximately 30 degrees or less (for example, approximately 25 degrees or less, approximately 20 degrees or less, approximately 15 degrees or less, approximately 12 degrees or less, approximately 10 degrees or less, approximately 9 degrees or less, approximately 8 degrees or less, approximately 7 degrees or less, approximately 6 degrees or less, approximately 5 degrees or less, approximately 4 degrees or less, and approximately 3 degrees or less). The defined range of solid angles in the horizontal and vertical field of view planes may be the same or different.

[0058] Generally, the dot patterns in contrast reduction areas 130a and 130b can be selected based on various design parameters to bring about a desired degree of light scattering on the user's retina. These design parameters generally include, for example, dot density, dot size and shape, and the refractive index of the dots, and will be discussed in more detail below. Ideally, the dot pattern is selected to provide high visual acuity in the fovea, reduced image contrast on other parts of the retina, and sufficiently low discomfort to allow the wearer to wear the glasses continuously for extended periods. For example, it may be desirable for a child to be comfortable wearing the glasses for most, if not all, of the day. Alternatively or additionally, the dot pattern can be designed for specific tasks, particularly those believed to strongly promote the extension of the eye length, such as video games, reading, or exposure to other wide-angle, high-contrast images. For example, in situations such as when a user experiences high contrast in their peripheral vision and / or when the wearer does not need to use their peripheral vision to move and change their orientation, it may be possible to increase the scattering intensity and scattering angle in the periphery, while considering awareness and self-respect may be of less interest. This is because reducing peripheral contrast can be highly effective in such high-contrast environments.

[0059] Reducing image contrast on the fovea of ​​the user's eye is believed to be less effective in controlling eye expansion than reducing image contrast on other parts of the user's retina. Therefore, the dot pattern can be adjusted to reduce (e.g., minimize) the amount of light scattered to the user's fovea, while a relatively large amount of light is scattered to other parts of the retina. The amount of scattered light on the fovea may be affected by the sizes of the transparent apertures 120a and 120b, respectively, but may also be affected by the properties of the dots, especially those closest to the transparent apertures. In some embodiments, for example, dots closest to the transparent apertures may be designed to have a less significant effect on scattering light than those further away. Alternatively or additionally, in some embodiments, dots closest to the transparent apertures may be designed to have a smaller forward scattering angle than those further away from the apertures.

[0060] In one embodiment, the dot can be designed to reduce narrow-angle scattering and increase wide-angle scattering to create a uniform light distribution / low-contrast signal on the retina, while maintaining clarity throughout the dimensions of the scattering center. For example, the dot can be designed to produce significantly wide forward scattering angles (e.g., deflected at angles greater than 2.5 degrees, more than 10%, more than 20%, more than 30%, more than 40%, more than 50%, etc.). Narrow forward scattering angles, i.e., within 2.5 degrees, can be kept relatively low (e.g., less than 50%, less than 40%, less than 30%, less than 20%).

[0061] Generally, various different measurement methods can be used to evaluate the performance of a dot pattern in order to optimize it for use in myopia-reducing eyeglasses. For example, a dot pattern can be empirically optimized based on physical measurements of lenses with different dot patterns. For example, light scattering can be characterized based on haze measurements, such as international testing standards for haze (e.g., ASTM D1003 and BS EN ISO 13468). Conventional haze measuring instruments, such as BYK-Gardner haze measuring instruments (e.g., Haze-Gard Plus instrument), can be used to measure how much light is transmitted through the lens overall, the amount of light transmitted without dispersion (e.g., within 0.5 degrees), how much is deflected at angles greater than 2.5 degrees, and transparency (amount within 2.5 degrees). Other instruments can also be used to characterize light scattering in order to empirically optimize the scattering pattern. For example, instruments that measure light diffusion by measuring light in an annular ring of approximately 2.5 degrees can be used (e.g., Hornell instruments).

[0062] Alternatively, or additionally, the dot pattern can be optimized using computer modeling software (e.g., Zemax or Code V).

[0063] In some embodiments, the dot pattern can be designed based on the optimization of a point distribution function that represents the image of the scattering centers on the retina. For example, the size, shape, and spacing of the scattering centers can be varied to evenly spread the illumination of the retina so that the retina outside the fovea is uniformly covered with scattered light to reduce (e.g., minimize) the contrast in this region of the retina.

[0064] Alternatively or additionally, the dot pattern can be designed based on the optimization of the modulation transfer function, known as the spatial frequency response of the human visual system. For example, the size, shape, and spacing of the scattering centers can be varied to smooth the attenuation over a range of spatial frequencies. The design parameters of the dot pattern can be varied, as desired, to increase or decrease certain spatial frequencies. Generally, the spatial frequencies of visual objects are 18 cycles per degree on the fine side and 1.5 cycles per degree on the coarse side. The dot pattern can be designed to allow signal augmentation in a subset of spatial frequencies within this range.

[0065] Using the measurement methods described above, the dot pattern can be evaluated based on the size and / or shape of the dots, both of which can be varied as desired. For example, the dots may be nearly round (e.g., spheres), elongated (e.g., ellipses), or irregularly shaped. Generally, the protrusions should be large enough to scatter visible light but small enough not to be disassembled by the wearer during normal use (e.g., a diameter as illustrated in Figure 1B). For example, a dot can have dimensions (measured in the xy plane) ranging from approximately 0.001 mm or more (e.g., approximately 0.005 mm or more, approximately 0.01 mm or more, approximately 0.015 mm or more, approximately 0.02 mm or more, approximately 0.025 mm or more, approximately 0.03 mm or more, approximately 0.035 mm or more, approximately 0.04 mm or more, approximately 0.045 mm or more, approximately 0.05 mm or more, approximately 0.055 mm or more, approximately 0.06 mm or more, approximately 0.07 mm or more, approximately 0.08 mm or more, approximately 0.09 mm or more, approximately 0.1 mm) to approximately 1 mm or less (e.g., approximately 0.9 mm or less, approximately 0.8 mm or less, approximately 0.7 mm or less, approximately 0.6 mm or less, approximately 0.5 mm or less, approximately 0.4 mm or less, approximately 0.3 mm or less, approximately 0.2 mm or less, approximately 0.1 mm).

[0066] For example, it should be noted that in smaller dots with dimensions corresponding to the wavelength of light (e.g., 0.001 mm to approximately 0.05 mm), light scattering can be attributed to Rayleigh scattering or Mie scattering. In larger protrusions, e.g., approximately 0.1 mm or larger, light scattering can be attributed to geometric scattering.

[0067] Generally, the dimensions of the dot may be the same across each lens or may vary. For example, the dimensions may increase or decrease as a function of the position of the projection when measured from a clear aperture, and / or as a function of the distance from the edge of the lens. In some embodiments, the dimensions of the projection change monotonically as the distance from the center of the lens increases (e.g., monotonically increasing or decreasing). In some cases, the monotonic increase / decrease of the dimensions involves linearly changing the diameter of the projection as a function of the distance from the center of the lens.

[0068] The dots shown in Figure 1B are arranged on a square grid with uniform spacing in each direction. This is because in the y direction, D y In the x-direction, D x This is shown by: Generally, to reduce myopia, the dots are spaced apart so that the dots collectively provide sufficient contrast reduction around the viewer. Typically, (under the condition that adjacent dots do not overlap or merge) smaller dot spacing results in greater contrast reduction. Generally, D x and D yThe dot spacing is in the range of approximately 0.05 mm (for example, approximately 0.1 mm or more, approximately 0.15 mm or more, approximately 0.2 mm or more, approximately 0.25 mm or more, approximately 0.3 mm or more, approximately 0.35 mm or more, approximately 0.4 mm or more, approximately 0.45 mm or more, approximately 0.5 mm or more, approximately 0.55 mm or more, approximately 0.6 mm or more, approximately 0.65 mm or more, approximately 0.7 mm or more, approximately 0.75 mm or more) to approximately 2 mm (for example, approximately 1.9 mm or less, approximately 1.8 mm or less, approximately 1.7 mm or less, approximately 1.6 mm or less, approximately 1.5 mm or less, approximately 1.4 mm or less, approximately 1.3 mm or less, approximately 1.2 mm or less, approximately 1.1 mm or less, approximately 1 mm or less, approximately 0.9 mm or less, approximately 0.8 mm or less). For example, the dot spacing may be 0.55 mm, 0.365 mm, or 0.240 mm.

[0069] While the dots shown in Figure 1B are arranged at equal intervals in the x and y directions, more generally, the spacing may differ in each direction. Furthermore, the protrusions can be arranged in a grid that is not square. For example, a hexagonal grid can be used. Irregular arrangements are also possible. For example, a random or semi-random dot arrangement can be used. In the case of a random pattern, the given dimensions are the average spacing distance of the dots in the x and y directions.

[0070] Generally, the coverage of a lens by dots can be varied as desired. Here, coverage refers to the ratio of the entire area of ​​the lens corresponding to a dot when projected onto the xy plane. Typically, lower dot coverage results in less scattering than higher dot coverage (assuming that individual dots are distinct, i.e., dots do not merge to form larger dots). Dot coverage can vary from 10% to approximately 75%. For example, dot coverage may be 15% or higher, 20% or higher, 25% or higher, 30% or higher, 35% or higher, 40% or higher, 45% or higher, 50%, or 55%. Dot coverage can be selected according to the user's comfort level, for example, to provide a level of peripheral vision that is comfortable enough for the wearer to voluntarily wear the glasses for extended periods (e.g., all day).

[0071] In Figure 1B, the dots are depicted as having a circular area, but more generally, dots can have other shapes. For example, a dot may be elongated in one direction (e.g., the x-direction or the y-direction), such as in the case of an elliptical dot. In some embodiments, the shape of the dots is random.

[0072] It is believed that light from the scene incident on the lens in the contrast reduction areas 130a and 130b between dots contributes to the image of the scene on the user's retina, while light from the scene incident on the dots does not. Furthermore, light incident on the dots is still transmitted to the retina and therefore has the effect of reducing image contrast without substantially reducing the intensity of light on the retina. Thus, it is believed that the amount of contrast reduction in the user's peripheral vision correlates (e.g., is approximately proportional) to the ratio of the surface area of ​​the contrast reduction areas covered by the dots. Generally, the dots occupy at least 10% (e.g., 20% or more, 30% or more, 40% or more, 50% or more, e.g., 90% or less, 80% or less, 70% or less, 60% or less) of the area (measured in the xy plane) of the contrast reduction areas 130a and 130b.

[0073] Generally, dot patterns reduce the contrast of images of objects in the wearer's peripheral vision without significantly degrading the wearer's vision within that area. Here, peripheral vision refers to the field of view outside the area of ​​the clear aperture. Image contrast in these areas can be reduced by 40% or more (e.g., 45%, 50%, 60%, 70%, 80%) compared to the image contrast seen using the clear aperture of the lens as determined. Contrast reduction can be set according to the needs of each individual case. Typical contrast reduction is believed to be in the range of approximately 50% to 55%. Contrast reduction of less than 50% can be used in very mild cases, while subjects with a stronger tendency may require a contrast reduction higher than 55%. Peripheral visual acuity, as determined by subjective refraction, can be corrected to 20 / 30 or more (e.g., 20 / 25 or more, 20 / 20 or more), while still reaching a significant contrast reduction.

[0074] Here, contrast refers to the difference in brightness between two objects within the same field of view. Therefore, contrast reduction refers to a change in this difference.

[0075] Contrast and contrast reduction can be measured in various ways. In some embodiments, contrast can be measured under controlled conditions based on the difference in brightness between different parts of a standard pattern, such as a black and white square checkerboard, obtained through a clear aperture and dot pattern of a lens.

[0076] Alternatively or additionally, contrast reduction can be determined based on the optical transfer function (OTF) of the lens (see, for example, http: / / www.montana.edu / jshaw / documents / 18%20EELE582_S15_OTFMTF.pdf). In the OTF, contrast is defined for the transmission of stimuli in which bright and dark regions are sinusoidally modulated at different "spatial frequencies". These stimuli appear as alternating bright and dark bars, where the spacing between the bars varies over a range. For all optical systems, the transmission of contrast is lowest with the sinusoidally modulated stimuli having the highest spatial frequency. The relationship that describes the transmission of contrast for all spatial frequencies is the OTF. The OTF can be obtained by performing a Fourier transform of the point distribution function. The point distribution function can be obtained by imaging a point light source through the lens onto a detector array and determining how the light from the point is dispersed across the detectors.

[0077] In cases of conflicting measurements, OTF is a preferred technique. In some embodiments, contrast can be estimated based on the ratio of the area of ​​the lens covered by the dots to the area of ​​the transparent aperture. This approximation assumes that all light hitting the dots is distributed uniformly across the entire retinal area, thereby reducing the amount of light available in the brighter areas of the image, which in turn adds light to the darker areas. Thus, contrast reduction can be calculated based on light transfer measurements performed through the transparent aperture and dot pattern of the lens.

[0078] Generally, ophthalmic lenses 110a and 110b can be transparent or tinted. That is, the lens may appear transparent and / or colorless, being optically transparent to all visible wavelengths, or it may appear tinted, containing a spectral filter. For example, an ophthalmic lens may include a filter that reduces the amount of red light transmitted to the wearer. It is believed that excessive stimulation of the L-cone of the human eye (especially in children) can cause the eye to elongate in an suboptimal manner, leading to myopia. Therefore, myopia in the wearer can be further reduced by spectrally filtering red light using an ophthalmic lens.

[0079] Spectral filtering can be achieved by adding a film to the surface of a lens. The film can be added by physically depositing a material onto the lens surface, coating the surface with a layer of material, or stacking a pre-formed film onto the surface. Suitable materials include absorbent filtering materials (e.g., dyes) or multilayer films that provide interference filtering. In some embodiments, spectral filtering can be achieved by incorporating the filtering material into the lens material itself and / or into the material used to form protrusions.

[0080] Referring to Figure 2, the effect of spectral filtering and contrast reduction from the dot pattern when using glasses 210 is shown by viewing black text on a white background. The white background relative to the text takes on a green appearance due to the filtering of red wavelengths by the glasses. The contrast of the image is unaffected with transparent apertures 220a and 220b, but is reduced somewhere else in the viewer's visual frame.

[0081] As described above, dots can generally be provided as projections and / or recesses on one or both sides of each lens, and / or as scattering inclusions in the lens material itself. In some embodiments, dots can be formed by an array of projections on each surface (e.g., the back or front) of lenses 110a and 110b.

[0082] The protrusions can be formed from an optically transparent material having a refractive index similar to that of the underlying lens, which is 1.60 for polycarbonate. For example, in embodiments where the lens is formed from polycarbonate, the protrusions can be formed from a polymer having a refractive index similar to PC, such as a photoactive polyurethane or epoxy-based plastic. In addition to PC, the lens itself can also be made from allyl diglycol carbonate plastic, a urethane-based monomer, or other impact-resistant monomer. Alternatively, the lens can be made from one of the higher-density, high-refractive-index plastics having a refractive index greater than 1.60. In some embodiments, the lens is made from an optically transparent material with a lower refractive index (e.g., CR39 is 1.50 and Trivex is 1.53).

[0083] Surface dot patterns can also be formed by creating recesses on one or both sides of a lens. For example, referring to Figure 3A, lens 300 includes a dot pattern formed from recesses 304 formed on the surface of the lens body 302. In this example, a meniscus lens with negative refractive power is depicted. More generally, lenses with positive refractive power or lenses with no refractive power can also be used. The recesses 304 can have similar dimensions and / or spacing to those of the protrusions described above. The recesses 304 can be formed using a variety of techniques, such as etching (e.g., physical etching or chemical etching) or removal of material from the lens surface (e.g., using laser radiation or molecular or ion beams). In some embodiments, the recesses are formed when the lens is shaped. Each recess corresponds to a region of the lens surface, in some cases when sufficient material is removed and the surface is roughened so that the lens surface scatters rather than refracts incident light.

[0084] The lens 300 also includes an optical coating 306 on the surface of the lens body 302 opposite the recess 304. The optical coating 306 can perform one or more functions, such as anti-reflection, spectral filtering (e.g., UV filtering), and / or a protective hard coat.

[0085] In some embodiments, contrast reduction is created by other diffusion structures, such as rough surfaces. Holographic diffusion or frosted glass diffusion can be used. In some embodiments, the diffusion can be provided by a film laminated on the surface of the lens.

[0086] Referring to Figure 3B, a cross-sectional view of another lens 310 is shown. This lens includes a lens body 312 containing an embedded scattering center 314. Lens 310 also includes an optical coating 316 on one of the surfaces of the lens body. Optical coating on both sides is also possible. The scattering center is generally formed from a material having a refractive index that does not match that of the bulk lens material. For example, when the lens is formed, transparent beads of the appropriate size can be dispersed in the lens material, and the refractive index of the bead material will be different from that of the bulk lens material. The transparent aperture is formed from the bulk lens material alone.

[0087] In some embodiments, embedded scattering centers 314 can be formed using a process that selectively induces refractive index changes in the bulk material of the lens. For example, exposure to a laser beam can induce localized changes in the refractive index of the bulk lens material, for example, through photochemical and / or photothermal interactions. Exemplary laser exposure methods that can be used to localize dot patterns are described in more detail below.

[0088] Generally, a mismatch in refractive index between lens material and dot material affects the amount of light scattered at each projection, as can be calculated using, for example, a point image distribution function. Typically, a larger mismatch in refractive index between materials results in more incident light being scattered. Therefore, refractive index mismatch can be used as a design parameter to optimize the scattering characteristics of the dot.

[0089] In some embodiments, the protruding material is selected to have a refractive index that is within 0.1 of the refractive index of the lens material (for example, within 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, 0.005, 0.002, 0.001) (when measured at one or more wavelengths in the visible light range).

[0090] In some embodiments, a larger refractive index mismatch (e.g., greater than 0.1) is possible. For example, the projection material can be selected to have a refractive index that differs from the refractive index of the lens material by 0.15 or more (e.g., 0.2 or more, 0.25 or more, 0.3 or more, 0.35 or more, up to about 0.4).

[0091] Generally, the refractive index of each dot may be the same or different. For example, if each dot is formed from the same material, each dot will have the same refractive index. Alternatively, in some embodiments, the refractive index can vary from dot to dot or between different groups of dots. For example, in one implementation, the refractive index mismatch between the dots and the lens bulk material may increase as the radial distance from the lens axis increases, such that the amount of light scattered from each dot increases as the radial distance from the lens axis increases.

[0092] In some cases, dots can be formed from a material that absorbs at least some of the light incident on it, such as a dye. The material can be selected to absorb broadband visible light or to absorb light only at certain wavelengths (e.g., short-wavelength or long-wavelength components). Light-absorbing materials are believed to help reduce glare and / or provide alternative design parameters for shaping the point image distribution function of the dot. In some embodiments, lens materials can be altered from transmittance to absorption at certain wavelengths by exposure to radiation. For example, lens materials can be charred by exposure to radiation to form light-absorbing centers in or on the surface of the lens material.

[0093] As described above, generally, the size, spacing, and arrangement of the dot pattern can be varied. In some embodiments, the dot pattern is characterized by, for example, a gradient in dot size and / or spacing. The dot pattern can be characterized by a gradient in the scattering effect of the dots (e.g., due to refractive index mismatches and / or gradients in the shape of each dot). A stepped dot pattern can reduce the prominence of the pattern. For example, a gradual transition from a transparent portion to a scattering portion of a lens can make it less noticeable than a sharp transition.

[0094] In some embodiments, the lens can be characterized by different zones in which the dot pattern varies from zone to zone. For example, referring to FIGS. 4A and 4B, lens 400 includes a transparent aperture 410, a transition zone 420, and a scattering zone 430. The transparent aperture 410 has a radius R410, and the transition zone 420 is an annular region surrounding a transparent aperture having an inner diameter R 410 and an outer diameter R 420 . The remainder of the lens area forms the scattering zone 430.

[0095] The transition zone 420 is characterized by a dot pattern that scatters less incident light than the dot pattern in the scattering zone 430, providing a transition in the scattering characteristics of the lens from the transparent aperture to the scattering zone. Such a transition can be advantageous in that it reduces scattering to the fovea compared to the scattering that would result if the scattering zone extended into the transparent aperture. A further advantage is that the transition zone can reduce the visibility of the dot pattern to the user and provide a more comfortable wearing experience. This can be particularly important for children. Here, the likelihood that a child will regularly wear glasses characterized by such lenses for a long period of time depends on the child's comfort level.

[0096] Generally, the dot pattern in the transition zone 420 may vary. In some embodiments, the transition zone is characterized by a uniform dot pattern in which the dots have the same shape and size and are uniformly spaced apart. Alternatively, in some embodiments, the dot pattern in the transition zone may be characterized by varying dot density, spacing, and / or size. For example, the dot pattern may result in the weakest scattering closest to the transparent aperture, R 410 From R 420 It can be selected to monotonically increase scattering as the radial distance increases. For example, in some embodiments, the dot density is R 410 From R 420 It increases monotonically (for example, linearly). For example, the dot diameter increases as the radial distance from the lens axis R 410 From R 420 As it increases, it can increase linearly from the first value (e.g., 0.05 mm) to the second value (e.g., 0.17 mm). Alternatively or additionally, the dot spacing is R 410 From R 420 It can be monotonically decreasing (for example, linearly).

[0097] Typically, R 410 The size range is approximately 1mm to 3mm (for example, 1.0mm to 1.1mm, 1.1mm to 1.2mm, 1.2mm to 1.3mm, 1.3mm to 1.4mm, 1.4mm to 1.5mm, 1.5mm to 1.6mm, 1.6mm to 1.7mm, 1.7mm to 1.8mm, 1.8mm to 1.9mm, 1.9mm to 2.0mm, 2.0mm to 2.1mm, 2.1mm to 2.2mm, 2.2mm to 2.3mm, 2.3mm to 2.4mm, 2.4mm to 2.5mm, 2.5mm to 2.6mm, 2.6mm to 2.7mm, 2.7mm to 2.8mm, 2.8mm to 2.9mm, 2.9mm to 3.0mm).

[0098] R 420The diameter may be in the range of approximately 2mm to approximately 6mm (for example, 2.0mm to 2.2mm, 2.2mm to 2.4mm, 2.4mm to 2.6mm, 2.6mm to 2.8mm, 2.8mm to 3.0mm, 3.0mm to 3.2mm, 3.2mm to 3.4mm, 3.4mm to 3.6mm, 3.6mm to 3.8mm, 3.8mm to 4.0mm, 4.0mm to 4.2mm, 4.2mm to 4.4mm, 4.4mm to 4.6mm, 4.6mm to 4.8mm, 4.8mm to 5.0mm, 5.0mm to 5.2mm, 5.2mm to 5.4mm, 5.4mm to 5.6mm, 5.6mm to 5.8mm, 5.8mm to 6.0mm).

[0099] In some embodiments, the dot pattern includes dots that are randomly displaced relative to a regular arrangement. By introducing random displacement, optical effects associated with regularly spaced scattering centers, such as star-shaped glare, can be reduced. For example, see https: / / www.slrlounge.com / diffraction-aperture-and-starburst-effects / , which describes star-shaped effects relevant to photography. Thus, including random displacement in the dot pattern can provide a more comfortable experience for the user compared to a similar dot pattern with uniformly spaced scattering centers. Alternatively or additionally, randomization of the dot pattern can reduce the visibility of the dot pattern to the observer by reducing optical effects (e.g., diffraction or interference effects) that appear in the reflected light.

[0100] Random displacements are illustrated in Figure 4C, where adjacent grid sites are at a distance D from each other in the x-direction. x , with a distance D between them in the y direction y The dots 401a to 401e are separated and positioned relative to the array grid. As shown in the figure, D x =D y However, more generally, the vertical grid spacing and the horizontal grid spacing may be different.

[0101] For each dot, δx = Ax ·D x ·RN[0,1] and δy=A y ·D y ·RN[0,1] and A x and A y These are the jitter amplitudes between 0 and 1 in the x and y directions, respectively, and may be the same or different. RN[0,1] is a random number between 0 and 1.

[0102] The dot size can also be randomly varied, which reduces optical effects associated with a uniformly sized dot arrangement, such as glare. For example, as shown in Figure 4C, the radial dimension of each dot can be changed from the nominal dot radius, r0. As illustrated, dot 401d has the nominal dot radius r0, while dots 401b and 401e have radii r b and r e They have, and both are greater than r0, r b ≠r e The dot radius is given by the formula r i It can be set according to =r0+Δr, where Δr=A r ·r0·RN[0,1], where i refers to the i-th dot, A r This is the dot radius jitter amplitude, which is set to a value between 0 and 1.

[0103] More generally, while the above example refers to the nominal dot radius of a circular dot, jitter can be applied to other dot size parameters depending on the application. For example, jitter can be applied to dot volume or other dot dimensions (e.g., x dimension, y dimension).

[0104] In some embodiments, the dot pattern may include both random jitter in the dot positions and random jitter in the dot sizes.

[0105] Exemplary dot patterns characterized by transition zones are shown in Figures 5A–5F. The patterns in Figures 5A, 5C, and 5E feature uniformly spaced dots within the scattering zone. The patterns in Figures 5B, 5D, and 5F feature dots that are randomly displaced from uniform spacing. The units for both the horizontal and vertical axes are mm. Each of Figures 5A–5F includes an inset showing a magnified view of the corresponding dot pattern. The parameters characterizing the dot patterns are provided in the table below.

[0106] [Table 1]

[0107] In some embodiments, the dot pattern is characterized, for example, by a gradient in dot size and / or spacing. The dot pattern may be characterized by a gradient in the scattering effect of the dots (for example, due to a mismatch in refractive index and / or a gradient in the shape of each dot). A stepped dot pattern can reduce the prominence of the pattern. For example, a stepped transition from the transparent portion to the scattering portion of the lens can be less conspicuous than a steep transition.

[0108] Refer to Figures 6A and 6B to see an example of a stepped dot pattern.

[0109] In detail, Figure 6A shows a stepped dot pattern 600 with varying spacing between adjacent dots. The transparent aperture 610 transitions to a low-density region 620. In region 620, the distance between adjacent dots is relatively large, thus rendering low-density dots in region 620. The low-density region 620 then transitions to a high-density region 630, where the spacing between adjacent dots is small, thus rendering high-density dots. The high-density region 630 then transitions to a low-density region 640, where the spacing between adjacent dots is increased again. As a result, due to the stepped transition from the transparent aperture 610 to the outer edge of the lens, the stepped dot pattern can be less noticeable compared to the transition to a more uniform dot pattern with higher density.

[0110] Dot density can be controlled not only by the spacing between adjacent dots but also by the dot size. For example, referring to Figure 6B, the dot pattern 650 features dots closer to the transparent aperture 660 that are smaller in size compared to dots closer to the edge 680 of the dot pattern.

[0111] In another example, a lens may have a stepped dot pattern in which both the dot size and the distance between dots vary.

[0112] The shape and / or composition of the dots can also vary radially, resulting in a stepped pattern. At the bulk scattering centers, a stepped pattern can be created, for example, by forming scattering centers with smaller refractive index discrepancies in the lens bulk material closer to the edges of the dot pattern compared to the scattering centers at the center of the dot pattern.

[0113] In some embodiments, information can be encoded into a dot pattern. For example, variations in the spacing, size, and / or shape of the dot pattern can be introduced according to a key, so that someone with the key can subsequently read the information. In some cases, information about the wearer, such as wearer identification information and information about the wearer's vision, can be encoded into the dot pattern.

[0114] In some embodiments, the dots may be dots of varying sizes. Referring to Figure 7A, the lens 700 includes a transparent aperture 702, as well as a dot pattern containing dots of different sizes, such as small dots 704 and large dots 706. In one embodiment, the small dots 704 are smaller than the large dots 706, and therefore the large dots 706 are larger than the small dots 704.

[0115] In one implementation, the small dot 704 and the large dot 706 can correspond to binary components. For example, the intensity of light reflected from the small dot 704 and the large dot 706 are different and can be interpreted as binary codes, so the small dot 704 corresponds to zero and the large dot 706 corresponds to one. When read as a string, the small dot 704 and the large dot 706 form a binary code sequence encoded with information that includes, but is not limited to, wearer identification information or visual information. For example, the encoded information may include lens prescription information.

[0116] In some implementations, there may be additional dot sizes other than the small dot size 704 and the large dot size 706; for example, the dot sizes of the dot pattern are not limited to two sizes. For example, when the sensor detects reflected light from the encoded dot pattern of lens 700, various dot sizes can be used to correspond to different outputs. The sensor can be configured to detect reflected light of three or more different intensities (for example, the intensities of reflected light from three or more different dot sizes of the dot pattern on lens 700).

[0117] In some embodiments, the dots may be dots in an annular ring having varying thickness. Referring to Figure 7B, the lens 720 includes a transparent aperture 722 as well as a dot pattern including “doughnuts” 724 (for example, dots having an annular ring and a transparent center) and dots 726.

[0118] In some implementations, donut 724 and dot 726 can correspond to binary components. For example, donut 724 may correspond to zero and dot 726 to one, and when read as a string, donut 724 and dot 726 form a binary code sequence encoded with information that includes, but is not limited to, wearer identification information or visual information. For example, the encoded information may include lens prescription information.

[0119] In one embodiment, the size, shape, and / or thickness of the annular ring of the donut 724 are changed, thus changing the intensity of the reflected light. The sensor can be configured to detect the changing intensity of the reflected light, which is then converted into an analog signal transmitted to a decoder. For example, an annular ring of a certain shape, size, and thickness of the donut 724 can correspond to predefined encoded information. For example, an annular ring having a certain thickness can correspond to the intensity of a predefined lens formulation, where increasing the thickness of the annular ring increases the intensity of the lens formulation.

[0120] In some embodiments, the dots can be shaped like symbols or logos, such as alphanumeric characters. Referring to Figure 7C, the lens 740 includes a transparent aperture 742 and a dot pattern of symbols 744.

[0121] In one implementation, the code 744 may be a logo, the same code, various codes, a simple shape, a complex shape, alphanumeric characters, letters, and / or words. For example, the code 744 may be a number representing the strength of a prescription. In another example, the code 744 may be a manufacturer's logo indicating where to order replacement lenses. In yet another example, the code 744 may be a shape indicating a particular wearer's diagnosis (for example, an ellipse with varying meridian length and height corresponding to the wearer's level of myopia and astigmatism).

[0122] Generally, variations in dot spacing, size, and / or shape are imperceptible to the naked eye and / or require a machine reading system to read encoded information. In some implementations, a microscope reader is used to read the encoded information. For example, a microscope or similar magnifying optical system can be used to allow an optometrist or lens technician to read encoded information from a lens.

[0123] In one implementation, a machine reading system is used to read the encoded information. Referring to Figure 8, the machine reading system 800 includes a lens 801 having a transparent aperture 802 surrounded by a dot pattern 803, a light emitter 812, light 814, reflected light 816, a sensor 818, a database 820, a decoder circuit 822, and a controller 824.

[0124] In some implementations, system 800 includes a light emitter 812. For example, the light emitter 812 illuminates the dot pattern 803 with light 814, such as an LED or laser. The dot pattern 803 is, for example, the encoded pattern illustrated in Figures 7A to 7C.

[0125] Light 814 is reflected (or not reflected) from the dot pattern 803 in the form of reflected light 816. The reflected light 816 has varying intensity (for example, the intensity ranges from no reflection to 100% reflection) because some dots can cause a complete reflection of light 814, or the absence of dots can cause no reflection of light 814. The reflected light 816 may also be a partial reflection of light 814. Similarly, in some embodiments, transmitted light or a combination of transmitted and reflected light can be used to read out the encoded information.

[0126] In one embodiment, system 800 includes a sensor 818. For example, sensor 818 is a photodetector, such as a photoelectric cell. Various implementations of sensor 818 may include, but are not limited to, laser scanners and camera-based readers. Sensor 818 detects and measures the intensity of reflected light 816 and outputs a signal. For example, the signal output by sensor 818 is an analog signal representing the intensity of reflected light 816. The signal generated by sensor 818 corresponding to the intensity of reflected light 816 is output to decoder circuit 822. For example, the intensity of reflected light 816 can be converted into a signal, such as an on / off pulse.

[0127] In some implementations, the signal generated by sensor 818 is sent to database 820. For example, database 820 can cross-reference codes to decode the signal (i.e., perform an image recognition lookup of a code from, for example, Figure 7C). Database 820 may contain banks of codes, images, alphanumeric codes, etc. For example, if the dot pattern 803 contains a complex shape, such as a logo or code, the sensor can send a signal related to that complex shape in database 820 for cross-referencing.

[0128] In one embodiment, the decoder circuit 822 decodes the signal from the sensor 818 and converts it into a digital signal. The digital signal is a digital representation of the signal from the sensor 818, such as a binary code where zero represents an off-pulse and 1 represents an on-pulse.

[0129] The decoder circuit 822 transmits a digital signal to the controller 824, which can read the digital signal. For example, the decoder circuit 822 can transmit a binary code that the controller 824 converts to text, thus allowing it to read the encoded information on the dot pattern 803.

[0130] While the above embodiment features an example where the contrast reduction area is annular (for example, a concentric circle surrounding a transparent aperture), other shapes are more generally possible. For example, an elongated (for example, elliptical) shape is possible. Generally, the contrast reduction area can cover the entire lens outside the transparent aperture, or it may cover only the portion of the lens that leaves the transparent lens intact at its periphery.

[0131] Generally, dots can be formed from lenses in a variety of ways. For example, dots can be formed using inkjet techniques, such as those disclosed in PCT / US2017 / 044635, filed July 31, 2017, entitled "OPHTHALMIC LENSES FOR TREATING MYOPIA," the entire contents of which are incorporated herein by reference.

[0132] In some embodiments, dots are formed on a lens by exposing the lens to laser radiation. The laser radiation interacts locally with the lens material to create the dots. Generally, as discussed in the examples below, a laser can be used to form dots either on the surface of a lens or in the bulk material of the lens. For example, dots can be created by exposing the lens surface to a laser beam with sufficient energy, leaving small indentations and / or rough spots on the surface. Dot patterns can be formed on a surface by selectively exposing areas of the lens surface to laser radiation. For example, the laser beam can be moved relative to the surface while the beam is pulsed. The relative motion between the beam and the lens surface can be achieved by moving the beam while keeping the surface fixed, moving the surface while keeping the beam fixed, or moving both the beam and the surface.

[0133] In general, the optical properties of dots formed on a lens surface using a laser can be affected in many ways. For example, the energy density of the laser beam pulse generally affects the physical and / or chemical interaction between the laser light and the lens material. For instance, at certain pulse energies, the lens material can be melted when exposed to form dots. At some pulse energies, dots can be formed by bubbling the lens material, which can occur at energies higher than lens melting. At some pulse energies, the interaction between the laser light and the lens material may result in a color change in the lens material (e.g., by charring). In yet another example, the lens material can be removed from the lens surface by excision.

[0134] Other lens parameters can also affect the properties of dots formed using a laser. These include the laser wavelength, exposure time (e.g., how long each dot location is exposed), and number of passes (e.g., one area is exposed multiple times, with other areas exposed in between), each of which can be selected to achieve the desired surface modification. In addition, the interaction between the laser light and the lens material depends on the lens material itself. For example, dots in a lens material with a lower glass transition temperature can be formed using lower pulse energy or fewer pulses, which is equivalent to dots in a lens material with a relatively high glass transition temperature.

[0135] In some embodiments, the laser and its operating parameters are selected to produce dots having a specific range of forward scattering angles, for example, between 3 and 30 degrees. In particular, the laser parameters can be selected to achieve surface modification resulting in a forward scattering angle of 15.5 to 19.5 degrees. In some cases, the laser parameters are selected to achieve a scattering efficiency (e.g., haze) of 10 to 50%. In particular, the laser parameters can be selected to achieve scattering efficiencies of 15% to 19% and 38% to 42%.

[0136] The resolution of the laser beam on the lens surface may be smaller than the desired dot size. For example, the beam resolution (such as that determined from the FWHM of the intensity profile) may be less than or equal to about 50% of the dot dimensions (e.g., less than or equal to about 25%, less than or equal to about 10%, less than or equal to about 5%, less than or equal to about 1%). In some embodiments, the beam may be capable of forming features having dimensions of less than or equal to 100 μm (e.g., less than or equal to 50 μm, less than or equal to 20 μm, less than or equal to 10 μm, less than or equal to 5 μm).

[0137] Referring to Figure 9, the laser system 900 for forming a dot on the surface of a lens includes a laser 920, a beam chopper 930, a focusing optical system 940, a mirror 950, and a stage 970. The laser 920 directs a laser beam towards the mirror 950, which deflects the beam towards the lens 901, and the lens 901 is positioned relative to the mirror 950 by the stage 970. An actuator 960 (e.g., a piezoelectric actuator) is attached to the mirror 950. The stage includes a lens mounting surface 980 that supports the lens 901. The laser system 900 also includes a controller (e.g., a computer controller) that communicates with the laser 920, the beam chopper 930, and the actuator 960.

[0138] The beam chopper 930 and focusing optical system 940 are positioned in the beam path. The chopper 930 periodically blocks the beam so that the lens 901 is exposed to discrete pulses of laser light. The focusing optical system 940, which typically includes one or more refractive elements (e.g., one or more lenses), focuses the beam to a sufficiently small spot on the surface of the lens 901 so that the area removed by the beam on the lens surface corresponds to a desired dot size. The actuator 960 reorients the mirror 950 relative to the beam to scan the pulsed beam to different target points on the lens surface. The controller 910 coordinates the operation of the laser 920, chopper 930, and actuator 960 so that the laser system forms a predetermined dot pattern on the lens.

[0139] In some implementations, the stage 970 also includes an actuator. The stage actuator may be a multi-axis actuator that moves the lens in two transverse directions perpendicular to the beam propagation direction, for example. Alternatively or additionally, the actuator can move the stage along the beam direction. Moving the stage along the beam direction can be used to maintain an exposed portion of the lens surface at the beam focus position, regardless of the curvature of the lens surface, thereby maintaining a nearly constant dot size across the lens surface. The stage actuator may also be controlled by a controller 910, which coordinates the movement of this stage with other elements of the system. In some embodiments, a stage actuator is used instead of a mirror actuator.

[0140] Generally, laser 920 may be any type of laser capable of generating light with sufficient energy to remove the lens material. Gas lasers, chemical lasers, dye lasers, solid-state lasers, and semiconductor lasers can be used. In some embodiments, infrared lasers can be used, such as CO2 lasers (having emission wavelengths of 9.4 μm or 10.6 μm). Commercially available laser systems can be used, such as the CO2 laser system manufactured by Universal Laser Systems, Inc. (Scottsdale, AZ) (e.g., the 60W VLS 4.60 system). In some embodiments, femtosecond lasers can be used. Commercially available femtosecond laser systems can be used, such as the TruMicro 2030 laser device in the TruLaser Station 5005 manufactured by Trumpf (Santa Clara, CA), to form dot patterns of the desired shape and size. The burst mode of such laser devices can achieve much higher burst energies compared to the maximum energy of a single pulse, resulting in higher removal rates. This exemplary laser system can provide a pulse duration of less than 400 femtoseconds with a maximum pulse energy of 50 μJ.

[0141] The pulse duration and pulse energy are typically selected to produce dots of a desired size. For example, in some embodiments, the laser 920 forms a predetermined dot pattern on the lens 901 by melting (e.g., laser etching) the surface of the lens 901. For example, laser etching involves the laser 920 heating and melting a portion of the surface of the lens 901 to form dots, resulting in recessed depressions and raised depressions around them that form the dots.

[0142] In one implementation, laser 920 uses laser foaming to form a predetermined dot pattern on lens 901. For example, when laser light interacts with the lens material, the material softens or melts, and gas bubbles are formed within the softened / melted material. As the material cools and returns to its room temperature state, these bubbles become trapped. The trapped bubbles efficiently scatter light, resulting in dots.

[0143] In one embodiment, the laser 920 forms a predetermined dot pattern on the lens 901 using laser marking. For example, the laser marking forms the predetermined dot pattern on the lens 901 by inducing a color change on the lens 901, for example, due to a chemical or physical modification of the portion of the lens 901 that forms the predetermined dot pattern. In another embodiment, the laser 920 forms a predetermined dot pattern on the lens 901 by using laser marking to burn the lens 901 and form a predetermined dot pattern on the lens 901.

[0144] In some implementations, the laser 920 uses excision to form a predetermined dot pattern on the lens 901. For example, the laser 920 is used to excise (e.g., remove material) the lens 901 by locally evaporating or sublimating the material of the lens 901, thereby forming a predetermined dot pattern. After excision, craters can be formed on the lens 901.

[0145] In some embodiments, to reduce the visibility of the dot pattern (for example, to reduce backscattering and reflection at the scattering center due to the excision crater), the surface of the excision crater on lens 901 is modified to reduce surface roughness. Reducing surface roughness can reduce the effect of scattering of light at small angles (for example, where the scattering angle is less than 3 degrees). For example, the surface of the excision crater on lens 901 can be modified by a second pass to melt the rough surface of the excision crater (for example, by using a lower energy beam). A lower energy beam can be achieved, for example, by defocusing laser 920 (for example, by increasing the beam width of laser 920). In some implementations, continuing to reduce the visibility of the dot pattern involves defocusing laser 920 multiple times. For example, the defocusing of the laser 920 affects the cone of the crater (for example, by blurring or smoothing the edges of the crater), so the defocusing is greater in several passes (e.g., the second, third, fourth, etc. passes) (for example, by increasing the beam width in each pass). In some implementations, reducing the visibility of the dot pattern involves multiple overlapping excisions, which are performed so that multiple overlapping excision craters make up one excision crater, such as two or more overlapping concentric circles.

[0146] In some implementations, reducing the visibility of the dot pattern involves coating the back of lens 920 with an anti-reflective layer. In some implementations, a reflective layer is coated on the front of the lens. This is particularly advantageous when laser cutting is performed on the back of lens 901. Generally, laser 920 has a stronger impact on the coating than the lens 901 material, and therefore affects the cone of the crater (for example, by blurring or smoothing the edges of the crater).

[0147] In some embodiments, a focusing optical system having a short depth of field can be used in conjunction with the curvature of the lens surface to provide a dot size that varies across the lens surface. For example, referring to system 900 in Figure 10, a laser system 1000 for forming a dot on the surface of a lens 1001 includes a laser 1020, a beam chopper 1030 (or other modulator for generating laser pulses), a focusing optical system 1040, a mirror 1050, and a stage 1080. The laser 1020 directs a laser beam 1025 towards the mirror 1050, the mirror 1050 deflects the beam 1025 towards the lens 1001, and the lens 1001 is positioned relative to the mirror 1050 by the stage 1080. An actuator 1060 is attached to the mirror 1050. The laser system 1000 also includes a controller 1010 that communicates with the laser 1020, the beam chopper 1030, and the actuator 1060.

[0148] The beam chopper 1030 and the focusing optical system 1040 are positioned in the beam path. The chopper 1030 periodically blocks the beam 1025 so that the lens 1001 is exposed to discrete pulses of laser light. The focusing optical system 1040 focuses the beam 1025 to a sufficiently small spot 1045 on or near the surface of the lens 1001 so that the area removed by the beam 1025 on the lens surface corresponds to a desired dot size. The actuator 1060 changes the orientation of the mirror 1050 relative to the beam 1025 to scan the pulsed beam 1025 to different target points on the lens surface. The controller 1010 adjusts the operation of the laser 1020, chopper 1030, and actuator 1060 so that the laser system 1000 forms a predetermined dot pattern on the lens 1001.

[0149] The moving stage 1080 moves the lens 1001 laterally and parallel to the focal plane 1035 of the laser beam 1025, as indicated by the arrows in Figure 10. Due to the curvature of the lens surface, the lens surface does not always coincide with the focal plane 1035 at the focal point 1045 of the laser beam, meaning that the intensity of the laser radiation on the lens surface varies depending on the lateral position of the lens relative to the spot 1045. In general, the amount of etching on the lens surface will depend on the intensity of the laser radiation received by the lens surface. Therefore, a position on the lens surface exposed to an out-of-focus beam will undergo less intense etching than a position where the lens surface coincides with the focal plane 1035. Consequently, assuming constant laser pulse time and lateral translation speed, the etching rate will be highest at the position where the lens surface coincides with the focal plane 1035, and will decrease as the lens is further translated from this position. Thus, a stepped pattern can be achieved simply based on the curvature of the lens surface.

[0150] Of course, other exposure parameters (for example, pulse time, pulse energy, and the composition of the dots, such as whether the dots are formed by multiple overlapping or near-cutting centers, or by foaming or melting zones) can be used together with or separately from the lens curvature to achieve the desired stepped dot pattern.

[0151] Laser systems can also be used to form scattering centers in the bulk material of lenses. In many cases, the effect of laser radiation on the bulk properties of an optical material (e.g., plastic or glass) depends on the intensity of the laser radiation. These changes may occur through one or more different mechanisms, such as photochemical changes, photothermal changes (e.g., light causes heating, and heat changes the properties of the material), and / or some other mechanism. Generally, as the intensity increases, the changes in the optical material become larger. In many cases, this change is not necessarily linear. For example, there may be some threshold intensity below which little, if any, changes occur in the bulk material. At some threshold intensity, changes begin to occur. For example, referring to Figure 11A, a plot of such a nonlinear relationship between refractive index change in a lens material and laser intensity is shown.

[0152] Laser radiation with a relatively low intensity I0 results in only a small change ΔR0 in the refractive index, but when the laser intensity reaches 2I0, a significant change ΔR0 in the refractive index occurs.

[0153] This nonlinear behavior of refractive index changes can be used to localize scattering centers embedded in lens materials. For example, a lens can be exposed to two or more laser beams, each with a beam intensity lower than the threshold intensity required to cause a significant refractive index change. While each laser beam is too weak to cause a visible change in refractive index, the region where the laser beams overlap (e.g., all laser beams can focus at the same point) can experience a sufficient change in refractive index to create a scattering center. Alternatively, if the beam focus is located within the bulk of the material, an optical system with a narrow focusing zone can be used.

[0154] For example, referring to Figure 11B, a laser system 1105 is shown that uses two overlapping beams to create an embedded scattering center in lens 1101. The laser system 1105 includes two lasers 1120A and 1120B, beam choppers 1130A and 1130B, focusing optics 1140A and 1140B, mirrors 1150A and 1150B, actuators 1160A and 1160B, and a stage 1180. A controller 1110 is connected to each of the actuators, focusing optics, and lasers. Each laser operates in a manner similar to that described in Figure 10. The focusing optics and mirrors are configured to focus beams 1185A and 1185B onto a common region 1190 inside lens 1101, and the intensity of the overlapping beams is sufficient to realize a change in the lens material and to form a scattering center. Outside the overlapping region, the intensity drops sharply to a value below an arbitrary threshold for a significant change in refractive index.

[0155] Three or more lasers can be used. Alternatively, or additionally, beams from a single laser can be split and directed separately to lenses so that they overlap in the target area and create scattering centers.

[0156] Other configurations are also possible. For example, as shown in Figure 11B, multiple laser beams can enter the lens from the same side rather than from opposite sides.

[0157] While the above description relates to ophthalmic lenses for eyeglasses, the disclosed principles can be applied to other forms of ophthalmic lenses, such as contact lenses. In some embodiments, the dot pattern can be provided on a contact lens to produce a similar therapeutic effect. The size and spacing of the dots in the dot pattern of the contact lens can be sized to define the range of solid angles in the user's field of view, corresponding to the dot pattern described above for eyeglass lenses.

[0158] Examples Dots were formed on the Trivex lens using a Trumpf Trumark 5000 marking laser station equipped with a nanosecond UV laser at a pulse repetition rate of 20 kHz. The laser station was operated at a scan speed of 1,000 mm / s and 100% power. The dots had a diameter of approximately 170 microns and resulted in haze of 15% to 42%, depending on the dot spacing. In some cases, dots were formed by marking two concentric overlapping circles with radii of approximately 0.06 mm and 0.03 mm, consisting of individual laser marks with a diameter of approximately 0.04 mm, resulting in a dot with an overall diameter of 0.17 mm. Adjacent dots were spaced by either 0.24 mm or 0.365 mm.

[0159] Other Embodiments Several embodiments are described. Other embodiments are covered in the following claims. [Explanation of Symbols]

[0160] 100 Myopia Reduction Glasses 101 A pair of frames 110a Ophthalmic Lenses 110b Ophthalmic Lenses 120a Transparent opening 120b Transparent opening 130a Contrast reduction area 130b Contrast reduction area 140 dots 210 Glasses 220a Transparent opening 220b Transparent opening 300 lenses 302 Lens body 304 recess 306 Optical Coatings 310 lens 312 Lens body 314 Embedded scattering centers 316 Optical Coatings 400 lens 401a dot 401b dot 401c dot 401d dot 401e dot 410 Transparent opening 420 Transition Zones 430 Scattering Zones 600 dot pattern 610 Transparent opening 620 Low density area 630 High density area 640 Low density area 650 dot pattern 660 Transparent opening 680 Edge 700 lens 702 Transparent opening 704 small dots 706 Large dots 720 lens 722 Transparent opening 724 Donuts 726 dots 740 lens 742 Transparent opening 744 dot pattern 800 Machine Reading System 801 Lens 802 Transparent opening 803 Dot Pattern 812 light emitter 814 light 816 Reflected light 818 Sensor 820 Databases 822 Decoder Circuit 824 Controller 900 Laser System 901 Lens 920 Laser 930 Beam Chopper 940 Focusing optical system 950 mirror 960 Actuator 970 stages 980 lens mounting surface 1000 Laser Systems 1001 Lens 1010 Controller 1020 Laser 1025 Laser beam 1030 Beam Chopper 1035 focal plane 1040 Focusing optical system 1045 Spot, Focus 1050 mirror 1060 Actuator 1080 Moving Stages 1101 Lens 1105 Laser System 1120A Laser 1120B laser 1130A Beam Chopper 1130B Beam Chopper 1140A focusing optical system 1140B Focusing optical system 1150A Mirror 1150B Mirror 1160A Actuator 1160B Actuator 1180 stages 1185A beam 1185B beam 1190 Common Area 1110 Controller

Claims

1. A method comprising the step of forming a plurality of spaced scattering centers on an ophthalmic lens, the size and shape of which are determined to scatter incident light incident on the ophthalmic lens, The scattering center is located at or near a corresponding array site in the two-dimensional array, and the distance between the array sites is a first distance D in a first direction within the array plane. ｘ The second distance D is in a second direction perpendicular to the first direction. ｙ It is formed in a pattern such as, The center of each scattering center is displaced from the corresponding array site by dimension δx in the first direction and dimension δy in the second direction. δx = A ｘ ・D ｘ ・RN[0,1], δy = A ｙ ・D ｙ ・RN[0,1], A ｘ and A ｙ A method in which each of the two is an amplitude between 0 and 1, and RN0,1 is a random number between 0 and 1.

2. The method according to claim 1, wherein the scattering center is formed on the surface of the ophthalmic lens.

3. The method according to claim 1, wherein the scattering center is formed in the bulk of the ophthalmic lens.

4. The method according to claim 1, wherein the step of forming the scattering center includes the step of exposing the ophthalmic lens to laser radiation.

5. The method according to claim 1, wherein the step of forming the scattering center includes the step of inkjet-spraying a material onto the surface of the ophthalmic lens.

6. The method according to claim 1, wherein the step of forming the scattering center is formed in a scattering region surrounding the transparent aperture in the ophthalmic lens.

7. The method according to claim 6, wherein the ophthalmic lens has a lens axis, and the transparent aperture and the scattering region are substantially centered on the lens axis.

8. The method according to claim 6, wherein the scattering region comprises a first scattering area and a second scattering area disposed between the transparent aperture and the first scattering area, the second scattering area comprising a scattering center that is sized and positioned to scatter incident light more weakly than the scattering center of the first scattering area.

9. The method according to claim 6, wherein the scattering region is an annular region.

10. The method according to claim 6, wherein the transparent opening is a circular opening.

11. The method according to claim 1, wherein the spacing between the aforementioned array sites is in the range of 0.2 mm to 1 mm.

12. The method according to claim 1, wherein the scattering center has the maximum dimension within the array plane in the range of 0.08 mm to 0.5 mm.

13. The method according to claim 1, wherein at least some of the scattering centers have dimensions that differ from the dimensions of the other scattering centers in the plane of arrangement.

14. The method according to claim 13, wherein the change in dimensions within the arrangement plane of at least some of the scattering centers is 0.5 times or less of the rated value.

15. The method according to claim 1, wherein at least some of the scattering centers have volumes that differ from the volumes of the other scattering centers.

16. The method according to claim 15, wherein the change in volume of at least some of the scattering centers is 0.5 times or less of the rated value.

17. The method according to claim 15, wherein the pattern includes an irregular change in the scattering center size.

18. The method according to claim 1, wherein the shape of the scattering centers within the arrangement plane is substantially circular.

19. The method according to claim 1, wherein the ophthalmic lens is one of a planar lens, a monofocal lens, or a multifocal lens.

20. The method according to claim 1, wherein the ophthalmic lens is one of eyeglass lenses and contact lenses.

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