Ophthalmic lenses with light scattering for treating myopia

Abstract

To provide a method comprising a step of forming on an ophthalmic lens a plurality of spaced 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 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 to Related Applications This application claims priority to Provisional Application No. 62 / 624,038, entitled "METHODS FOR FORMING OPHTHALMIC LENSES FOR TREATING MYOPIA", filed on January 30, 2018; Provisional Application No. 62 / 663,938, entitled "OPHTHALMIC LENSES WITH LIGHT SCATTERING FOR TREATING MYOPIA", filed on April 27, 2018; and Provisional Application No. 62 / 671,992, entitled "OPHTHALMIC LENSES WITH LIGHT SCATTERING FOR TREATING MYOPIA", filed on May 15, 2018. The entire contents of each of these provisional applications are hereby incorporated by reference into this specification.

[0002] The present invention features an ophthalmic lens for treating myopia and weakening the progression of myopia.

Background Art

[0003] The eye is an optical sensor, and light from an external light source is focused by a lens onto the surface of the retina, which is an array of wavelength - dependent optical sensors. Each of the various shapes that the eye's lens can adopt is related to the focal length at which external light 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. The eye's lens, in each of the various shapes that the eye's lens can adopt, optimally or nearly optimally focuses light emitted or reflected by external objects within a certain range of distances from the eye, and focuses objects at distances outside that range sub - optimally or fails to focus on the objects.

[0004] In people 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 that is close to the optimal focus for distant objects. The eyes of people with normal vision focus on distant objects without sending nerve input to the muscles that apply force to change the shape of the eye's lens, a process called "accommodation." Closer nearby objects are focused as a result of accommodation by normal individuals.

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

[0006] Typically, infants are born farsighted, with an eye length that is shorter than required for optimal or near-optimal focus on distant objects without accommodation. During the period of normal eye development, called "emmetropization," the axial length of the eye extends to a length that, compared to other dimensions of the eye, results in near-optimal focus on distant objects without accommodation. Ideally, the biological process maintains a relatively eye length that is close to optimal for the size of the eye as the eye grows to its final adult size. However, in myopic people, the relative axial length of the eye with respect to the overall eye size continues to increase during development beyond the length that results in near-optimal focus on distant objects, leading to increasingly significant myopia.

[0007] Myopia is believed to be influenced by behavioral factors as well as genetic factors. Therefore, myopia can be reduced by treatment devices that address behavioral factors. For example, a treatment device for treating disorders related to the length of the eye, including myopia, is described in U.S. Patent Application Publication No. 2011 / 0313058.

Prior Art Documents

Patent Documents

[0008] [Patent Document 1] U.S. Patent Application Publication No. 2011 / 0313058 [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 are disclosed that reduce signals in the retina responsible for elongation of the eye. 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, which is believed to reduce the elongation of the eye associated with the progression of myopia, is reduced. The aperture without dots disposed on the lens axis allows the user to experience the highest visual acuity when viewing on-axis objects, while objects in the periphery of the user's field of view appear with reduced contrast and clarity.

[0011] In these glasses, compared to those commonly used to correct (but not treat) refractive anomalies, the focused image has reduced contrast in the peripheral regions of the retina. 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 luminance difference / average luminance. Experiments have shown that such amounts of contrast reduction in the peripheral regions of the retina have an important impact on the eye's physiology related to the mechanisms 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 the ratio of the distance between adjacent lattice sites. The jitter amplitude can be 0.5 or less (e.g., 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).

[0015] The scattering center can 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 is 0.5 times or less of the rated value (for example, 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).

[0016] The scattering center can have a volume that varies randomly from the rated volume, and the random variation is equal to or less than the jitter amplitude. The product of the jitter amplitude and the rated volume is 0.5 or less (for example, 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).

[0017] The lens can have a lens axis, and the aperture and the annular region are substantially centered on the lens axis.

[0018] The scattering region can include a first scattering area and a second scattering area disposed between the transparent aperture and the first scattering area. The second scattering area includes scattering centers sized and arranged to scatter incident light less strongly than the scattering centers of the first scattering area. The lens can have a lens axis, and the aperture as well as the first and second scattering areas are substantially centered on the lens axis. The scattering centers in the second scattering area have dimensions that increase monotonically (for example, linearly or geometrically) as the radial distance from the lens axis increases. The lens can have a lens axis, and the aperture as well as the first and second scattering areas are substantially centered on the lens axis. The scattering centers in the second scattering area have dimensions and / or volumes that vary monotonically (for example, linearly or geometrically) as the radial distance from the lens axis increases.

[0019] Irregular variations in the scatter center spacing may be random variations. Irregular variations in the scatter center size may be random variations.

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

[0021] The scatter centers may be approximately circular in shape. The scatter centers can be shaped like a logo or an alphanumeric character.

[0022] The lens may be a plano lens, a single - focus lens, or a multi - focus lens. The lens may be an eyeglass lens or a contact lens.

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

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

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

[0026] Embodiments of the eyeglasses can include one or more of the following features and / or features of other aspects. For example, the dot pattern can reduce the image contrast of an object seen 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%, up to 80%) compared to the image contrast of an object seen through the transparent aperture.

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

[0028] In another aspect, the present invention is a method for treating an impairment related to the length of the eye, comprising the steps of identifying an impairment related to the length of the patient's eye and reducing the contrast of an image in the periphery of the patient's vision using the eyeglasses described above.

[0029] Generally, in yet another aspect, the present invention features a method comprising the steps of focusing a laser beam and exposing an ophthalmic lens to the focused laser radiation to form an optical scattering feature with a pattern on the surface of the ophthalmic lens. The step of exposing the ophthalmic lens includes creating relative movement 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 focus.

[0030] Implementation of the method can include one or more of the following features and / or features of other aspects. For example, the optical scattering feature formed by the laser beam can vary depending on the location of the lens surface relative to the focus. The degree of scattering due to the optical scattering feature can decrease as the distance of the lens surface from the focus increases.

[0031] The pattern can 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 can include discrete dots. The dots can be arranged in an array such that each dot is separated by a distance of 1 mm or less and each dot has a maximum dimension of 0.5 mm or less. The transparent aperture can be a dot-free region having a maximum dimension greater than 1 mm.

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

[0033] The ophthalmic lens can be exposed to pulsed laser radiation.

[0034] The laser can have sufficient energy to remove lens material from the surface of the lens.

[0035] The laser can have a power in the range of 0.5 W to 60 W.

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

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

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

[0039] Generally, in a further aspect, the present invention is a method of forming scattering centers in an ophthalmic lens, the method comprising exposing a region 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. The implementation of this method can include one or more features of other aspects.

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

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

[0042] The laser radiation in the overlapping beams can interact with the lens material to change the refractive index of the lens material.

[0043] The laser radiation in the overlapping beams can change the refractive index of the lens material by causing a photochemical change in the lens material.

[0044] The laser radiation in the overlapping beams can change the refractive index of the lens material by causing a photothermal change in the lens material.

[0045] In another aspect, the present invention includes an eyeglass frame and a pair of ophthalmic lenses attached to the frame, and each lens includes a pattern distributed across each lens formed using one of the above methods. A pair of eyeglasses is characterized by this.

[0046] Embodiments of the eyeglasses can include one or more of the following features and / or features of other aspects. For example, each pattern can include an area with optical scattering features surrounding a transparent opening without scattering features. The dot pattern can reduce the image contrast of the object seen 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 seen through the transparent opening.

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

[0048] Among the advantages, the disclosed embodiments are characterized by glasses that include the feature of reducing signals in the retina responsible for elongation of the eye length for both eyes' lenses without reducing the user's on-axis vision of either eye to the point of confusion. For example, by providing a dot pattern that moderately blurs the wearer's peripheral vision while allowing normal on-axis vision through a transparent aperture, the wearer can use it throughout the day. The disclosed embodiments can provide therapeutic benefits to the user using only a single pair of glasses for both eyes, as opposed to techniques that include using different pairs of glasses alternately or using accessories for the glasses.

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

[0050] The dot pattern can also be optimized for the comfort of the viewer. For example, the dot pattern can be characterized by a transition zone that smoothes the transition from the transparent 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 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 user's experience of glare. Reducing the diffraction or interference effects during reflection can also reduce the visibility of the dot pattern to third parties.

[0051] Information can be encoded into dot patterns. For example, the dots can be shaped like symbols (e.g., alphanumeric symbols) or logos. Alternatively or additionally, the dot shape, size, and / or spacing can be varied according to a key for embedding information in the dot pattern.

[0052] The disclosed embodiments can enable a dot pattern for reducing eye elongation to be effectively and economically formed on a conventional ophthalmic lens, for example, by forming the dot pattern on the surface of the lens or within the bulk of the lens.

Brief Description of the Drawings

[0053]

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[0054] Referring to FIG. 1A, a myopia reducing spectacle 100 is disclosed that enables treatment of both eyes simultaneously without significantly compromising clear vision. Further, the spectacles are sufficiently robust and unobtrusive such that the wearer can engage in the same daily activities without the spectacles becoming unusable or embarrassing the wearer about their appearance. This is particularly desirable since spectacles are typically used to stop children's eyes from growing longer.

[0055] The myopia reducing spectacle 100 is composed of a pair of frames 101 and ophthalmic lenses 110a and 110b attached to the frames. Generally, the ophthalmic lenses may be plano lenses, single - focus lenses (e.g., having positive or negative refractive power), or multi - focus lenses (e.g., bifocal lenses or progressive multi - focus lenses). The ophthalmic lenses 110a and 110b each have a transparent aperture 120a and 120b respectively, each surrounded by a contrast reduction area 130a and 130b. The transparent apertures 120a and 120b are positioned to coincide with the wearer's on - axis viewing position, while the contrast reduction areas 130a and 130b correspond to the wearer's peripheral vision. Also referring to FIG. 1B, the contrast reduction areas 130a and 130b are composed of an array of dots 140 that reduce the contrast of objects in the wearer's peripheral vision by scattering the light passing through those areas to the wearer's eyes. 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 visual field cone 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 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) (in the xy plane). Here, the aperture is circular, as depicted in FIG. 1A for example, and this dimension corresponds to the diameter of the circle (i.e., A x = A y ), but non-circular (e.g., elliptical, polygonal, A x ≠ A y ) apertures are also possible.

[0057] The transparent aperture can define a range of solid angles of about 30 degrees or less (e.g., about 25 degrees or less, about 20 degrees or less, about 15 degrees or less, about 12 degrees or less, about 10 degrees or less, about 9 degrees or less, about 8 degrees or less, about 7 degrees or less, about 6 degrees or less, about 5 degrees or less, about 4 degrees or less, about 3 degrees or less) in the viewer's visual field. In the horizontal and vertical visual field planes, the defined range of solid angles can be the same or different.

[0058] Generally, the dot patterns in the contrast reduction regions 130a and 130b can be selected based on various design parameters to provide a desired degree of light scattering on the user's retina. Generally, these design parameters include, for example, dot density, dot size and shape, and the refractive index of the dots, which will be discussed in more detail below. Ideally, the dot pattern is selected to provide high visual acuity on the fovea, reduction of image contrast on other parts of the retina, and a sufficiently low discomfort to allow the wearer to wear continuously for a long time. For example, it may be desirable for a child to be comfortable wearing glasses for most, if not all, of the day. Alternatively or additionally, the dot pattern can be designed for specific tasks, particularly tasks that are believed to strongly promote the elongation of the eye axis, such as, for example, video games, reading, or other tasks that expose the user to high-contrast images at a wide angle. For example, in such situations (such as when the user experiences high contrast in the user's peripheral vision and / or the wearer experiences a situation where the wearer does not need to use peripheral vision to move and orient themselves), the scattering intensity and scattering angle in the periphery can be increased, while consideration of awareness and self-esteem may be less of a concern. This can result in a higher effect on peripheral contrast reduction in such high-contrast environments.

[0059] Reducing the image contrast on the fovea of the user's eye is believed to be less effective in controlling the dilation of the eye than reducing the image contrast on other parts of the user's retina. Thus, the dot pattern can be adjusted to reduce (e.g., minimize) the light scattered towards the user's fovea, while a relatively large amount of light on other parts of the retina is scattered. 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 nature of the dots, especially those closest to the transparent apertures. In some embodiments, for example, the dots closest to the transparent apertures can be designed to have a lower light scattering effect than those further away. Alternatively or additionally, in some embodiments, the dots closest to the transparent apertures can be designed to have a smaller forward scattering angle than those further away from the apertures.

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

[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 glasses. For example, the dot pattern can be optimized empirically, for example, based on physical measurements of lenses having different dot patterns. For example, light scattering can be characterized based on haze measurements, such as international test standards for haze (e.g., ASTM D1003 and BS EN ISO 13468). Conventional haze measuring instruments, such as BYK-Gardner haze measuring instruments (such as the Haze-Gard Plus instrument), which measure how much light is transmitted through the lens as a whole, the amount of light transmitted without being scattered (e.g., within 0.5 degrees), how much is deflected at angles greater than 2.5 degrees, and transparency (amount within 2.5 degrees), can be used. Other instruments can also be used to characterize light scattering in order to optimize the scattering pattern empirically. For example, an instrument that measures light diffusion by measuring the light in an annular ring of about 2.5 degrees can be used (e.g., an instrument made by Hornell).

[0062] Alternatively or additionally, the dot pattern can be optimized by 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 spread 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 outer retina of the fovea is evenly 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, which is called 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 of the spatial frequency range. The design parameters of the dot pattern can be varied to increase or decrease a certain spatial frequency as desired. Generally, the spatial frequency of the visual object is 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 an increase in the signal at a certain subset of the spatial frequencies within this range.

[0065] Using the above measurement method, the dot pattern can be evaluated based on the size and / or shape of the dots, and both can be varied as desired. For example, the dots can be approximately round (e.g., spherical), elongated (e.g., elliptical), or irregular in shape. Generally, the protrusions should have dimensions (e.g., the diameter as shown in FIG. 1B) that are large enough to scatter visible light but small enough not to be disassembled by the wearer during normal use. For example, the dots can have dimensions (measured in the xy plane) in the range of about 0.001 mm or more (e.g., about 0.005 mm or more, about 0.01 mm or more, about 0.015 mm or more, about 0.02 mm or more, about 0.025 mm or more, about 0.03 mm or more, about 0.035 mm or more, about 0.04 mm or more, about 0.045 mm or more, about 0.05 mm or more, about 0.055 mm or more, about 0.06 mm or more, about 0.07 mm or more, about 0.08 mm or more, about 0.09 mm or more, about 0.1 mm) to about 1 mm or less (e.g., about 0.9 mm or less, about 0.8 mm or less, about 0.7 mm or less, about 0.6 mm or less, about 0.5 mm or less, about 0.4 mm or less, about 0.3 mm or less, about 0.2 mm or less, about 0.1 mm).

[0066] For example, it should be noted that for smaller dots having dimensions corresponding to the wavelength of light (e.g., 0.001 mm to about 0.05 mm), the light scattering can be considered Rayleigh scattering or Mie scattering. For larger protrusions, e.g., about 0.1 mm or more, the light scattering can be due to geometric scattering.

[0067] Generally, the dot dimensions can be the same or vary across each lens. For example, the dimensions can increase or decrease as a function of the position of the protrusion when measured from, e.g., a transparent aperture, and / or as a function of the distance from the edge of the lens. In some embodiments, the dimension of the protrusion changes monotonically as the distance from the center of the lens increases (e.g., monotonically increases or monotonically decreases). In some cases, the monotonic increase / decrease in dimension includes linearly varying the diameter of the protrusion as a function of the distance from the center of the lens.

[0068] The dots shown in FIG. 1B are arranged on a square grid spaced apart by a uniform amount in each direction. This is shown by D y in the y - direction and D x in the x - direction. Generally, for myopia reduction, the dots are spaced so that they collectively provide sufficient contrast reduction around the viewer. Typically, (with the condition that adjacent dots do not overlap or fuse), as the dot spacing decreases, the contrast reduction increases. Generally, D x and D yis in the range of about 0.05 mm (for example, about 0.1 mm or more, about 0.15 mm or more, about 0.2 mm or more, about 0.25 mm or more, about 0.3 mm or more, about 0.35 mm or more, about 0.4 mm or more, about 0.45 mm or more, about 0.5 mm or more, about 0.55 mm or more, about 0.6 mm or more, about 0.65 mm or more, about 0.7 mm or more, about 0.75 mm or more) to about 2 mm (for example, about 1.9 mm or less, about 1.8 mm or less, about 1.7 mm or less, about 1.6 mm or less, about 1.5 mm or less, about 1.4 mm or less, about 1.3 mm or less, about 1.2 mm or less, about 1.1 mm or less, about 1 mm or less, about 0.9 mm or less, about 0.8 mm or less). As an example, the dot spacing may be 0.55 mm, 0.365 mm, or 0.240 mm.

[0069] While the dots shown in FIG. 1B are arranged at equal intervals in the x and y directions, more generally, the intervals may be different in each direction. Further, the protrusions can be arranged in a non-square lattice. For example, a hexagonal lattice can be used. An irregular arrangement is also possible. For example, a random or semi-random dot arrangement can be used. In the case of a random pattern, the given dimension is the average separation distance of the dots in the x and y directions.

[0070] Generally, the coverage of the lens by the dots can be changed as desired. Here, coverage refers to the ratio of the entire area of the lens corresponding to the dots when projected onto the xy plane. Typically, when the dot coverage is low, less scattering will result than when the dot coverage is high (assuming that the individual dots are separate, i.e., the dots do not fuse to form larger dots). The dot coverage can vary from 10% or more to about 75%. For example, the dot coverage may be 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45% or more, 50% or 55%, etc. The 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 a long period (for example, all day).

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

[0072] The light from the scene incident on the lenses in the contrast reduction regions 130a and 130b between the dots is believed to contribute to the image of the scene on the user's retina, while the light from the scene incident on the dots is not believed to contribute. Further, the light incident on the dots is still transmitted through the retina, and thus has the effect of reducing the image contrast without substantially reducing the light intensity in the retina. Therefore, it is believed that the amount of contrast reduction in the user's peripheral vision correlates (e.g., is approximately proportional) with the ratio of the surface area of the contrast reduction region 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 regions 130a and 130b.

[0073] Generally, a dot pattern reduces the contrast of an image of an object in the peripheral vision of the wearer without significantly degrading the vision of a viewer looking within the region of the wearer's peripheral vision. Here, peripheral vision refers to the field of vision outside the region of the transparent aperture. The image contrast in these regions can be reduced by more than 40% (e.g., more than 45%, more than 50%, more than 60%, more than 70%, more than 80%) relative to the image contrast seen using the transparent aperture of the lens as determined. The contrast reduction can be set according to the requirements of each individual case. A typical contrast reduction is believed to be in the range of about 50% - 55%. A contrast reduction of less than 50% can be used in very mild cases, while more predisposed subjects may require a contrast reduction higher than 55%. The peripheral visual acuity can be corrected to 20 / 30 or better (e.g., 20 / 25 or better, 20 / 20 or better) as determined by subjective refraction, while still achieving a significant contrast reduction.

[0074] Here, contrast refers to the difference in luminance between two objects within the same field of vision. Thus, contrast reduction refers to the change in this difference.

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

[0076] Alternatively or in addition, contrast reduction can be determined based on the optical transfer function (OTF) of the lens (see, e.g., http: / / www.montana.edu / jshaw / documents / 18%20EELE582_S15_OTFMTF.pdf). In the OTF, contrast is defined for the transmission of stimuli that are sinusoidally modulated at different "spatial frequencies" for bright and dark regions. These stimuli appear like 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 for sinusoidally varying stimuli with the highest spatial frequencies. 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 spread function. The point spread 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 spread across the detector.

[0077] In the case of inverse measurements, the OTF is a preferred technique. In some embodiments, contrast can be estimated based on the ratio of the area of the lens covered by dots compared to the area of the transparent aperture. In this approximation, it is assumed that all the light hitting the dots is evenly spread across the entire retinal area, thereby reducing the amount of light available in the brighter regions of the image and adding light to the darker regions. Thus, contrast reduction can be calculated based on optical transmission measurements performed through the transparent aperture and dot pattern of the lens.

[0078] Generally, ophthalmic lenses 110a and 110b can be transparent or colored. That is, the lenses can be optically transmissive at all visible wavelengths and appear transparent and / or colorless, or can include a spectral filter and appear colored. For example, an ophthalmic lens can include a filter that reduces the amount of red light transmitted to the wearer. It is believed that excessive stimulation of the L cones in the human (especially children's) eyes can cause the eyes to become non-optimal for long periods and may lead to myopia. Thus, by spectrally filtering red light using an ophthalmic lens, the myopia of the wearer can be further reduced.

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

[0080] Referring to FIG. 2, the effects of spectral filtering and contrast reduction from a dot pattern using glasses 210 are shown by looking at black text on a white background. The white background against the text takes on a green appearance due to the filtering of the red wavelength by the glasses. The contrast of the image is not affected by the transparent apertures 220a and 220b, but is reduced elsewhere in the viewer's visual frame.

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

[0082] The protrusions can be formed from an optically transmissive 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 photoactive polyurethane or epoxy-based plastic. In addition to PC, the lens itself can also be made from allyl diglycol carbonate plastic, urethane-based monomer, or other impact-resistant monomers. 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 transmissive material having a lower refractive index (e.g., CR39 is 1.50 and Trivex is 1.53).

[0083] The surface dot pattern can also be formed by creating recesses on one or both sides of the lens. For example, referring to FIG. 3A, the 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 having a negative refractive power is depicted. More generally, a lens having a positive refractive power or a lens having no refractive power can also be used. The recesses 304 can have dimensions and / or spacing similar to those of the protrusions described above. The recesses 304 can be formed using various 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 molded. In some cases, when sufficient material is removed to roughen the surface such that the lens surface scatters rather than refracts incident light, each recess corresponds to a region of the lens surface.

[0084] The lens 300 also includes an optical coating 306 on the surface of the lens body 302 opposite the recesses 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 diffusing structures, such as a rough surface. A holographic diffuser or a ground glass diffuser can be used. In some embodiments, the diffuser can be provided by a film laminated on the surface of the lens.

[0086] Referring to FIG. 3B, a cross-sectional view of another lens 310 is shown. This lens includes a lens body 312 that contains embedded scattering centers 314. The lens 310 also includes an optical coating 316 on one of the surfaces of the lens body. Double-sided optical coatings are also possible. The scattering centers are generally formed from a material having a refractive index that does not match the bulk of the lens material. For example, when the lens is molded, transmissive beads of an appropriate size can be dispersed in the lens material, and the refractive index of the bead material is different from the refractive index of the bulk lens material. The transparent openings are formed from only the bulk lens material.

[0087] In some embodiments, the 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, when exposed to a laser beam, local changes in the refractive index of the bulk lens material can be caused, for example, via photochemical and / or photothermal interactions. Exemplary laser exposure methods that can be used to localize the dot pattern are described in more detail below.

[0088] Generally, the refractive index mismatch between the lens material and the dot material affects the amount of light scattered at each protrusion, as calculated, for example, using a point spread function. Typically, as the refractive index mismatch between the materials increases, more of the incident light will be scattered. Thus, the refractive index mismatch can be used as a design parameter to optimize the scattering characteristics of the dots.

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

[0090] In some embodiments, a larger (e.g., greater than 0.1) refractive index mismatch is possible. For example, the protrusion material can be selected to have a refractive index that differs from that 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 the dots are each formed from the same material, each dot has the same refractive index. Instead, in some embodiments, the refractive index can be varied 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, the dots can be formed from a material that absorbs at least some of the light incident thereon, such as a dye. The material can be selected to absorb broadband visible light or to absorb light only at a certain wavelength (e.g., absorb short wavelength components or long wavelength components). It is believed that the light absorbing material can help reduce glare and / or provide another design parameter for shaping the point spread function of the dots. In some embodiments, by exposure to radiation, the lens material can be changed from being transmissive to being absorptive at a certain wavelength. For example, by exposure to radiation to form light absorbing centers in or on the surface of the lens material, the lens material can be focused.

[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 of dot size and / or spacing. The dot pattern can be characterized by a gradient of the scattering effect of the dots (e.g., due to a refractive index mismatch and / or a gradient in the shape of each dot). A stepped dot pattern can reduce the prominence of the pattern. For example, by a gradual transition from the transparent portion to the scattering portion of the lens, it can be made less noticeable than a sharp transition.

[0094] In some embodiments, the lens can be characterized by different zones where 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, and provides 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 comfort level of the child.

[0096] Generally, the dot pattern in the transition zone 420 may change. In some embodiments, the transition zone features a uniform dot pattern where the dots have the same shape and size and are evenly spaced. Instead, in certain embodiments, the dot pattern in the transition zone can be characterized by changing the dot density, spacing, and / or size. For example, the dot pattern can be selected to provide the weakest scattering closest to the transparent aperture and monotonically increase the scattering with a radius distance increasing from R 410 to R 420 . For example, in some embodiments, the dot density monotonically increases (e.g., linearly) from R 410 to R 420 . As an example, the dot diameter can linearly increase from a first value (e.g., 0.05 mm) to a second value (e.g., 0.17 mm) as the radius distance from the lens axis increases from R 410 to R 420 . Alternatively or additionally, the dot spacing can monotonically decrease (e.g., linearly) from R 410 to R 420 .

[0097] Typically, R 410 is in the range of about 1 mm to about 3 mm (e.g., 1.0 mm - 1.1 mm, 1.1 mm - 1.2 mm, 1.2 mm - 1.3 mm, 1.3 mm - 1.4 mm, 1.4 mm - 1.5 mm, 1.5 mm - 1.6 mm, 1.6 mm - 1.7 mm, 1.7 mm - 1.8 mm, 1.8 mm - 1.9 mm, 1.9 mm - 2.0 mm, 2.0 mm - 2.1 mm, 2.1 mm - 2.2 mm, 2.2 mm - 2.3 mm, 2.3 mm - 2.4 mm, 2.4 mm - 2.5 mm, 2.5 mm - 2.6 mm, 2.6 mm - 2.7 mm, 2.7 mm - 2.8 mm, 2.8 mm - 2.9 mm, 2.9 mm - 3.0 mm).

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

[0099] In some embodiments, the dot pattern includes dots randomly displaced with respect to a regular array. By introducing random displacements, optical effects associated with regularly spaced scattering centers, such as a starburst glare, can be reduced. See, for example, https: / / www.slrlounge.com / diffraction-aperture-and-starburst-effects / , which describes starburst effects as related to photography. Thus, including random displacements 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, randomizing the dot pattern can reduce optical effects (such as diffraction or interference effects) that appear in the reflected light and reduce the visibility of the dot pattern to the observer.

[0100] The random displacements are illustrated in FIG. 4C, where dots 401a - 401e are positioned with respect to an array lattice in which adjacent lattice sites are separated from each other by a distance D in the x - direction x , and a distance D in the y - direction y . As shown, D x = D y , but more generally, the vertical lattice spacing and the horizontal lattice spacing may be different.

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

[0102] The dot size can also vary randomly, which can reduce optical effects related to an array of dots of uniform size, such as glare. For example, as shown in Figure 4C, the radial dimension of each dot can be varied from the nominal dot radius, r0. As shown, while dot 401d has the nominal dot radius r0, dots 401b and 401e have radii r b and r e respectively, both of which are larger than r0, and r b ≠ r e is true. The dot radius can be set according to the formula r i = r0 + Δr, where Δr = A r ·r0·RN[0,1], where i refers to the i - th dot, and A r is the dot radius jitter amplitude set to a value between 0 and 1 for each dot.

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

[0104] In some embodiments, the dot pattern can include both random jitter in dot position and random jitter in dot size.

[0105] Exemplary dot patterns characterized by a transition zone are shown in FIGS. 5A - 5F. The patterns in FIGS. 5A, 5C, and 5E are characterized by dots evenly spaced in the scattering zone. The patterns in FIGS. 5B, 5D, and 5F are characterized by dots randomly displaced from the even spacing. The units for both the horizontal and vertical axes are mm. Each of FIGS. 5A - 5F includes an inset showing an enlarged view of the corresponding dot pattern. The parameters characterizing the dot pattern are provided in the table below. The dots are characterized by being randomly displaced from the even spacing. The units for both the horizontal and vertical axes are mm. Each of FIGS. 5A - 5F includes an inset showing an enlarged view of the corresponding dot pattern. The parameters characterizing the dot pattern are provided in the table below.

[0106]

Table 1

[0107] In some embodiments, the dot pattern is characterized by, for example, a dot size and / or a gradient of the spacing. The dot pattern can be characterized by a gradient of the scattering effect of the dots (e.g., due to a refractive index mismatch 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 a lens can make it less noticeable than a sharp transition.

[0108] Referring to FIGS. 6A and 6B, an exemplary stepped dot pattern is shown.

[0109] Specifically, FIG. 6A shows a stepped dot pattern 600 having different intervals between adjacent dots. The transparent opening 610 transitions to the 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 the high-density region 630. There, the interval between adjacent dots is small, thus rendering high-density dots. The high-density region 630 then transitions to the low-density region 640. Here, the interval between adjacent dots is increased again. As a result, due to the stepped transition from the transparent opening 610 to the outer edge of the lens, the stepped dot pattern can be made less prominent compared to the transition to a uniform dot pattern at a higher density.

[0110] Dot density can be controlled not only by the interval between adjacent dots but also by dot size. For example, referring to FIG. 6B, the dot pattern 650 features dots closer to the transparent opening 660 having a smaller size compared to dots closer to the edge 680 of the dot pattern.

[0111] In another example, the lens can have a stepped dot pattern where both dot size and dot-to-dot distance vary.

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

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

[0114] In some embodiments, the dots can be dots of varying sizes. Referring to FIG. 7A, lens 700 includes a transparent aperture 702 and a dot pattern including dots of different sizes, such as small dot 704 and large dot 706. In one embodiment, small dot 704 is smaller than large dot 706, and thus large dot 706 is larger than small dot 704.

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

[0116] In one implementation, there can be additional dot sizes other than small dot size 704 and large dot size 706. For example, the dot sizes of the dot pattern are not limited to two sizes. For example, when a sensor detects the reflected light from the encoded dot pattern of lens 700, various dot sizes corresponding to different outputs can be used. The sensor can be configured to detect reflected light of three or more different intensities (e.g., the intensities of the 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 of an annular ring having a varying thickness. Referring to FIG. 7B, lens 720 includes a transparent aperture 722 as well as a dot pattern including a “donut” 724 (e.g., a dot having an annular ring and a transparent center portion) and a dot 726.

[0118] In one implementation, the donut 724 and the dot 726 can correspond to binary components. For example, the donut 724 corresponds to zero and the dot 726 corresponds to one, and when read as a character string, the donut 724 and the dot 726 form a binary code sequence encoded with information including, but not limited to, identification information or visual information of the wearer. For example, the encoded information can include prescription information of the lens.

[0119] In one embodiment, the size, shape, and / or thickness of the annular ring of the donut 724 varies, and thus the intensity of the reflected light varies. The sensor can be configured to detect the varying intensity of the reflected light in order to convert it into an analog signal that is transmitted to a decoder. For example, an annular ring having a certain shape, size, and thickness of the donut 724 can correspond to pre-defined encoded information. For example, an annular ring having a certain thickness can correspond to the intensity of a pre-defined lens prescription, and as the thickness of the annular ring increases, the intensity of the lens prescription increases.

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

[0121] In one implementation, the code 744 may be a logo, the same code, various codes, simple shapes, complex shapes, alphanumerics, characters, 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 another example, the code 744 may be a shape (e.g., an ellipse with varying meridian lengths and heights corresponding to the nearsightedness and astigmatism levels of a particular wearer) indicating the diagnosis of a particular wearer.

[0122] Generally, changes in dot spacing, size, and / or shape read information encoded using a machine-readable system that is not perceivable by human vision with the naked eye. In one implementation, a microscope reader is used to read information encoded using a microscope or similar magnifying optical system to enable an optometrist or lens technician to read the information encoded from the lens.

[0123] In one implementation, a machine-readable system is used to read information encoded. Referring to FIG. 8, the machine-readable 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, the 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 a laser. The dot pattern 803 is, for example, the encoded pattern illustrated in FIGS. 7A - 7C.

[0125] Light 814 is reflected (or not reflected) from dot pattern 803 in the form of reflected light 816. Since complete reflection of light 814 can occur by a dot or no reflection can occur due to the absence of a dot, the intensity of reflected light 816 varies (e.g., the intensity ranges from no reflection to 100% reflection). Reflected light 816 may be a partial reflection of light 814. Similarly, in some embodiments, transmitted light or a combination of transmitted light and reflected light can be used to read the encoded information.

[0126] In one embodiment, system 800 includes sensor 818. For example, sensor 818 is a light detector such as a photocell. Various implementations of sensor 818 can 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 search for the code from, for example, FIG. 7C). Database 820 can contain a bank of codes, images, alphanumeric codes, etc. For example, if dot pattern 803 includes a complex shape such as a logo or a code, the sensor can send the signal related to that complex shape in database 820 for cross-reference.

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

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

[0130] While the above embodiment features an example where the contrast reduction region is annular (e.g., concentric circles surrounding a transparent aperture), more generally, other shapes are possible. For example, an elongated (e.g., oval) shape is possible. Generally, the contrast reduction region can cover the entire lens outside the transparent aperture or cover only a portion leaving the transparent lens at the periphery of the lens.

[0131] Generally, the dots can be formed on the lens in various ways. For example, the dots can be formed using an inkjet technique such as those disclosed in PCT / US2017 / 044635, filed July 31, 2017, entitled "OPHTHALMIC LENSES FOR TREATING MYOPIA," the entire content of which is incorporated herein by reference.

[0132] In some embodiments, the dots are formed on the 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 the lens or within the bulk material of the lens. For example, by exposing the lens surface to a laser beam having sufficient energy, dots can be created by leaving small indentations and / or rough spots on the surface. By selectively exposing regions of the lens surface to the laser radiation, a dot pattern can be formed on the surface. For example, the laser beam can be moved relative to the surface while the beam is pulsed. The relative movement between the beam and the lens surface can be effected 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] Generally, the optical properties of dots formed using a laser on the lens surface can be affected in many ways. For example, the energy density of the laser beam pulse will generally affect the physical and / or chemical interaction of the laser light with the lens material. For example, at a certain pulse energy, the lens material can be melted when exposing the lens material to form the dots. At some pulse energies, dots can be formed by foaming the lens material. This can occur at high energies relative to lens melting. At some pulse energies, the interaction between the laser light and the lens material can result in a color change to the lens material (e.g., by charring). In yet other examples, the lens material can be removed from the lens surface by ablation.

[0134] Other lens parameters may also affect the nature of the dots formed using the laser. These include the laser wavelength, the exposure time (e.g., how long each dot position is exposed), and the number of passes (e.g., exposing an area 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 a lower pulse energy or fewer pulses corresponding to dots in a lens material with a relatively higher glass transition temperature.

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

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

[0137] Referring to FIG. 9, a laser system 900 for forming dots 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 toward the mirror 950, which deflects the beam to 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 the 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 generally 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 such that the area removed by the beam on the lens surface corresponds to the desired dot size. The actuator 960 changes the orientation of the mirror 950 with respect to the beam to scan the pulsed beam to different target points on the lens surface. The controller 910 adjusts the operation of the laser 920, the chopper 930, and the actuator 960 so that the laser system forms a predefined dot pattern on the lens.

[0139] In some implementations, stage 970 also includes actuators. The stage actuator can be, for example, a multi-axis actuator that moves the lens in two lateral directions perpendicular to the beam propagation direction. 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 the exposed portion of the lens surface at the beam's focus position regardless of the curvature of the lens surface, thereby maintaining a substantially constant dot size across the lens surface. The stage actuator can also be controlled by 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, the laser 920 can be any type of laser capable of generating light having sufficient energy to remove lens material. Gas lasers, chemical lasers, dye lasers, solid-state lasers, and semiconductor lasers can be used. In some embodiments, an infrared laser such as a CO2 laser (having an emission wavelength of 9.4 μm or 10.6 μm) can be used. For example, a commercially available laser system such as a CO2 laser system (e.g., 60W VLS 4.60 system) manufactured by Universal Laser Systems, Inc. (Scottsdale, AZ) can be used. In some embodiments, a femtosecond laser can be used. For example, a commercially available femtosecond laser system (such as the TruMicro 2030 laser device of TruLaser Station 5005) manufactured by Trumpf (Santa Clara, CA) can be used to form a dot pattern of a desired shape and size. The burst mode of such a laser device can achieve a much higher burst energy compared to the maximum energy of a single pulse and can result in a higher ablation rate. 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 result in dots of a desired size. For example, in some embodiments, the laser 920 forms a pre-defined dot pattern on the lens 901 by melting the surface of the lens 901 (e.g., laser etching). For example, laser etching heats and melts a portion of the surface of the lens 901 with the laser 920 to expand the melted material of the lens 901, resulting in indented depressions forming the dots and raised depressions around them.

[0142] In one implementation, the laser 920 forms a predefined dot pattern on the lens 901 using laser foaming. For example, when the laser light interacts with the lens material, the material softens or melts, and gas bubbles are formed in the softened / melted material. When the material cools and returns to its room temperature state, these bubbles are trapped. The trapped bubbles can scatter light efficiently and result in dots.

[0143] In an embodiment, the laser 920 forms a predefined dot pattern on the lens 901 using laser marking. For example, laser marking forms a predefined 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 a portion of the lens 901 that forms the predefined dot pattern. In another embodiment, the laser 920 forms a predefined dot pattern on the lens 901 by using laser marking to focus the lens 901 and forming a predefined dot pattern on the lens 901.

[0144] In some implementations, the laser 920 forms a predefined dot pattern on the lens 901 using ablation. For example, the laser 920 is used to ablate the lens 901 (e.g., remove material) by locally evaporating or sublimating the material of the lens 901 to form a predefined dot pattern. After ablation, craters can be formed on the lens 901.

[0145] In some embodiments, to reduce the visibility of the dot pattern (e.g., to reduce backscattering and reflection at the scattering centers caused by the ablation craters), the surface of the ablation crater on the lens 901 is modified to reduce the surface roughness. Reducing the surface roughness can reduce the effect of small-angle light scattering (e.g., where the scattering angle is less than 3 degrees). For example, the surface of the ablation crater on the lens 901 can be modified by a second pass to melt the rough surface of the ablation crater (e.g., by using a lower energy beam). The lower energy beam can be achieved, for example, by defocusing the laser 920 (e.g., by increasing the beam width of the laser 920). In some implementations, reducing the visibility of the dot pattern continues to include defocusing the laser 920 multiple times. For example, defocusing the laser 920 affects the cone of the crater (e.g., by blurring or smoothing the edge of the crater), so defocusing is increased (e.g., in each pass where the beam width is increased) in some passes (e.g., the second, third, fourth, etc. passes). In some implementations, reducing the visibility of the dot pattern includes multiple overlapping ablations implemented such that one ablation crater is formed by multiple overlapping ablation craters, such as two or more overlapping concentric circles.

[0146] In some implementations, reducing the visibility of the dot pattern includes coating an antireflection layer on the back surface of the lens 920. In some implementations, a reflective layer is coated on the front surface of the lens. This is particularly advantageous when laser ablation is performed on the back surface of the lens 901. Generally, the laser 920 has a stronger impact on the coating than on the lens 901 material and thus affects the cone of the crater (e.g., by blurring or smoothing the edge of the crater).

[0147] In some embodiments, a focusing optical system having a short depth of focus can be used in conjunction with the curvature of the lens surface to provide a dot size that varies across the surface of the lens. For example, referring to FIG. 10, similar to system 900, a laser system 1000 for forming dots on the surface of 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. Laser 1020 directs laser beam 1025 toward mirror 1050, which deflects beam 1025 toward lens 1001, and lens 1001 is positioned relative to mirror 1050 by stage 1080. Actuator 1060 is attached to mirror 1050. Laser system 1000 also includes a controller 1010 that communicates with laser 1020, beam chopper 1030, and actuator 1060.

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

[0149] The moving stage 1080 moves the lens 1001 horizontally parallel to the focal plane 1035 of the laser beam 1025 as indicated by the arrow in FIG. 10. Due to the curvature of the lens surface, the lens surface does not always coincide with the focal plane 1035 at the focus 1045 of the laser beam, which means that the intensity of the laser radiation on the lens surface varies according to the lateral position of the lens with respect to the spot 1045. Generally, the amount by which the lens surface is etched will depend on the intensity of the laser radiation received by the lens surface. Therefore, the positions on the lens surface exposed to the unfocused beam receive less intense etching than the positions where the lens surface coincides with the focal plane 1035. As a result, assuming that the laser pulse time and the horizontal translation speed are constant, the etching speed is highest at the position where the lens surface coincides with the focal plane 1035, and the etching speed decreases as the lens is further translated from this location. Therefore, the stepped pattern can simply be achieved based on the curvature of the lens surface.

[0150] Of course, other exposure parameters (e.g., pulse time, pulse energy, the formation of dots such as multiple overlaps or near the excision center, or the formation of dots by the firing or melting zone) can be used together with or separately from the lens curvature to achieve the desired stepped dot pattern.

[0151] The laser system can also be used to form scattering centers in the bulk material of the lens. 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 can occur via one or more different mechanisms such as photochemical changes, photothermal changes (e.g., light brings about heating and the 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 a linear relationship. For example, there may be some threshold intensity below which little change occurs in the bulk material, if any. At any threshold intensity, the change begins to occur. For example, referring to FIG. 11A, a plot of such a non-linear relationship between the refractive index change in the lens material and the laser intensity is shown.

[0152] Laser radiation having 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] Using such non-linear behavior of the refractive index change, the scattering centers embedded in the lens material can be localized. For example, the lens can be exposed to two or more laser beams each having a beam intensity lower than the threshold intensity for causing a significant refractive index change. Each laser beam is too weak to cause a visible change in the refractive index, while the region where the laser beams overlap (e.g., all the laser beams can be focused at the same point) can experience a sufficient change in the refractive index corresponding to the creation of the scattering centers. Alternatively, when the focus of the beam is placed within the bulk of the material, an optical system with a narrow focus zone can be used.

[0154] For example, referring to FIG. 11B, a laser system 1105 is shown that uses two overlapping beams to create an embedded scattering center in lens 1101. 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 stage 1180. Controller 1110 is connected to each of the actuators, focusing optics, and lasers. Each laser operates in a manner similar to that described in FIG. 10. The focusing optics and mirrors are configured to focus beams 1185A and 1185B into a common region 1190 inside lens 1101, and the intensity of the overlapping beams is sufficient to create a change in the lens material and sufficient to form a scattering center. Outside the overlapping region, the intensity drops rapidly to a value below any threshold for significant refractive index change.

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

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

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

[0158] Examples Dots were formed on Trivex lenses 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% output power. The dots had a diameter of approximately 170 microns and produced 15% - 42% haze depending on the dot spacing. In some cases, the 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 dots with an overall diameter of 0.17 mm. Adjacent dots were spaced either 0.24 mm or 0.365 mm apart.

[0159] Other embodiments Some embodiments are described. Other embodiments are within the scope of the following claims.

Description of reference numerals

[0160] 100 Myopia reduction glasses 101 A pair of frames 110a Ophthalmic lens 110b Ophthalmic lens 120a Transparent opening 120b Transparent opening 130a Contrast reduction area 130b Contrast reduction area 140 Dot 210 Glasses 220a Transparent opening 220b Transparent opening 300 Lens 302 Lens body 304 Recess 306 Optical coating 310 Lens 312 Lens body 314 Embedded scattering center 316 Optical coating 400 Lens 401a Dot 401b dots 401c dots 401d dots 401e dots 410 transparent opening 420 transition zone 430 scattering zone 600 dot pattern 610 transparent opening 620 low-density region 630 high-density region 640 low-density region 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 donut 726 dots 740 lens 742 transparent opening 744 dot pattern 800 machine-readable system 801 lens 802 transparent opening 803 dot pattern 812 light emitter 814 light 816 reflected light 818 sensor 820 database 822 decoder circuit 824 controller 900 laser system 901 lens 920 laser 930 beam chopper 940 focusing optical system 950 mirror 960 actuator 970 stage 980 lens mounting surface 1000 Laser System 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 Stage 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 Stage 1185A Beam 1185B Beam 1190 Common Region 1110 Controller

Claims

1. A method comprising the step of forming a plurality of spaced-apart scattering centers sized and shaped to scatter incident light incident on the ophthalmic lens on the ophthalmic lens, The scattering centers are located at or near the corresponding array sites of 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 and a second distance D in a second direction perpendicular to the first direction ｙ and are formed in a pattern such that wherein the center of each scattering center is displaced from the corresponding array site by a dimension δx in the first direction and a dimension δy in the second direction, δx = A ｘ · D ｘ · is RN[0, 1], δy = A ｙ · D ｙ · is RN[0, 1], and A ｘ and A ｙ each having an amplitude between 0 and 1, and RN0,1 being a random number between 0 and 1, method.

2. The method of claim 1, wherein the scattering centers are formed on the surface of the ophthalmic lens.

3. The method of claim 1, wherein the scattering centers are formed in the bulk of the ophthalmic lens.

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

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

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

7. The method of 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 of claim 6, wherein the scattering region comprises a first scattering zone and a second scattering zone disposed between the transparent aperture and the first scattering zone, the second scattering zone having scattering centers sized and arranged to scatter incident light less strongly than the scattering centers of the first scattering zone.

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

10. The method of claim 6, wherein the transparent aperture is a circular aperture.

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

12. The method of claim 1, wherein the scattering centers have a maximum dimension in the array plane in the range of 0.08 mm to 0.5 mm.

13. The method of claim 1, wherein at least some of the scattering centers have dimensions that vary from the dimensions of the array plane of other scattering centers.

14. The method of claim 13, wherein the variation in the dimensions of at least some of the scattering centers in the array plane is less than or equal to 0.5 times the rated value.

15. The method of claim 1, wherein at least some of the scattering centers have a volume that varies from the volume of other scattering centers.

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

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

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

19. The method according to claim 1, wherein the ophthalmic lens is any one of a plano lens, a single-focus lens, and a multi-focus lens.

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

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