Ophthalmic lens with transition light scattering centers for myopia management

Abstract

Ophthalmic lenses for reducing progression of myopia are disclosed. The ophthalmic lens includes a lens body having a first curved surface and a second curved, the lens body having a central point; a light diffusion area, the light diffusion area comprising a plurality of scattering centers sized and shaped to scatter incident light, a density of the scattering centers varying over the light diffusion area. The light diffusion area includes a first zone surrounding the central point, the first zone having the highest density of scattering centers of the light diffusion area; and a second zone between the first zone and the central point, the second zone having a density of scattering centers lower than the first zone. The second zone extends to a point on the lens 15 mm or more from the central point in at least one radial direction measured from the central point.

Description

Attorney Docket No.45336-0026WO1 OPHTHALMIC LENS WITH TRANSITION LIGHT SCATTERING CENTERS FOR MYOPIA MANAGEMENT FIELD OF THE INVENTION

[0001] The invention features ophthalmic lenses for treating myopia and managing myopia progression and, more particularly, ophthalmic lenses with a transition zone. BACKGROUND

[0002] The eye is an optical sensor in which light from external sources is focused, by a lens, onto the retina, an array of wavelength-dependent photosensors. Each of the various shapes that the eye lens can adopt is associated with a focal length at which external light rays are optimally or near-optimally focused to produce inverted images on the surface of the retina that correspond to external images observed by the eye. The eye lens, in each of the various shapes that the eye lens can adopt, optimally or near-optimally, focuses light emitted by, or reflected from external objects that lie within a certain range of distances from the eye, and less optimally focuses, or fails to focus objects that lie outside that range of distances.

[0003] In normal-sighted individuals, the axial length of the eye, or distance from the lens to the surface of the retina, corresponds to a focal length for near-optimal focusing of distant objects. The eyes of normal-sighted individuals focus distant objects without nervous input to muscles which apply forces to alter the shape of the eye lens, a process referred to as “accommodation.” Closer, nearby objects are focused, by normal individuals, as a result of accommodation.

[0004] Many people, however, suffer from eye-length-related disorders, such as myopia (“nearsightedness”). In myopic individuals, the axial length of the eye is longer than the axial length required to focus distant objects without accommodation. As a result, myopic individuals can view near objects clearly, but objects further away are blurry. While myopic individuals are generally capable of accommodation, the average distance at which they can focus objects is shorter than that for normal-sighted individuals.

[0005] Typically, infants are born hyperopic, with eye lengths shorter than needed for optimal or near-optimal focusing of distant objects without accommodation. During normal development of the eye, referred to as “emmetropization,” the axial length of the eye, relative to other dimensions of the eye, increases up to a length that provides near-optimal focusing ofAttorney Docket No.45336-0026WO1 distant objects without accommodation. Ideally, biological processes maintain the near- optimal relative eye length to eye size as the eye grows to final, adult size. However, in myopic individuals, the relative axial length of the eye to overall eye size continues to increase during development, past a length that provides near-optimal focusing of distant objects, which can eventually lead to high myopia.

[0006] It is believed that myopia is caused by behavioral factors as well as genetic factors. Accordingly, myopia may be mitigated by therapeutic devices which address behavioral factors. For example, therapeutic devices for treating eye-length related disorders, including myopia, are described in U.S. Pub. No.2011 / 0313058A1. SUMMARY

[0007] Ophthalmic lenses, including spectacle lenses and contact lenses, are disclosed that reduce contrast signals at the cone photoreceptor level in the retina, responsible for growth of eye length. The lenses include a treatment zone, which incorporates a light diffusion area with multiple zones providing differing amounts of light scattering. Generally, the treatment zone includes two zones: 1. a zone of maximum scattering centers and 2. a transition zone between the zone of maximum scattering centers and a central point of the lens. The transition zone provides a lower level of light scattering than the zone of maximum scattering. In some examples, the lower level of light scattering is originated from the fact that a lower density of scattering centers exists in the transition zone compared to the maximum scattering zone. The lenses can include a clear central aperture, e.g., encompassing the central point of the lens, and the transition zone can be located, radially, between the clear aperture and the maximum scattering zone. The maximum scattering zone occupies at least some (e.g., all) of the wearer’s peripheral visual field and the light scattering from this zone provides sufficient contrast reduction of images at the retina, decreasing the signal that makes eye to grow and hence slowing myopia progression. The transition zone between the clear, central zone and the maximum scattering zone provides a transition in the rate of forward and backward scattering from the clear, central zone to the maximum scattering zone. In certain examples, the transition zone reduces backscattering and conspicuity of the scattering center pattern to an observer, without significantly reducing the therapeutic effect of the lenses.

[0008] Alternatively, or additionally, the transition zone can provide a gradual transition from no light scattering (for a clear aperture) or lower scattering levels of light (e.g., alongAttorney Docket No.45336-0026WO1 the visual axis) to the maximum scattering zone. A gradual transition over a sufficiently large area of the lens can provide a wearer with more comfortable user experience compared to similar lenses without a transition zone or with a small transition zone.

[0009] It is believed that the reduced conspicuity of the scattering center patterns due to the transition zone can result in a more consistent use by certain wearers, especially children, who may otherwise be self-conscious during everyday use (e.g., at school or otherwise among peers) of more conspicuous devices and / or less inclined to regularly use lenses of lower visual comfort. For example, a graded scattering center pattern that constitutes a large transition zone surrounding the aperture can be used to reduce conspicuity of patterns to third parties.

[0010] Among other advantages, disclosed embodiments feature spectacles that include features that reduce signals in the retina responsible for growth of eye length on the lenses for both eyes, without diminishing the user's on-axis vision in either eye to an extent that is disruptive to the user. For example, providing a scattering center pattern that modestly blurs the wearer's peripheral vision while allowing normal on-axis viewing through a clear central aperture can allow for all-day, everyday use by the wearer.

[0011] Moreover, the scattering centers can be largely unnoticeable to others, particularly where scattering centers are clear. This may have a positive impact on the consistency of use when the conspicuity of the device reduces the likelihood of consistent use for certain users, such as children, who tend to be self-conscious during use.

[0012] Scattering center patterns can also be optimized for viewer comfort. For example, patterns featuring a transition zone soften the transition from the lens's clear vision zone to the peripheral zone in the viewer's visual field. In some examples, random jitter can be applied to patterns (e.g., to the scattering centers size and / or spacing). Such randomization can reduce undesirable optical effects associated with uniform arrays of optical features (e.g., diffractive or interference effects). For instance, random jitter can be used to reduce glare experienced by the user. It can also reduce conspicuity of patterns to third parties by reducing diffractive or interference effects in reflection.

[0013] Disclosed embodiments feature devices with subtly arranged patterns for mitigating eye lengthening. These devices can be efficiently and economically formed on conventional ophthalmic lenses, for example by forming scattering centers on a surface or in the bulk of the lens. The success of the therapeutic effect in treating and preventing the progression of myopia is increased with consistent use, which can be made more likely byAttorney Docket No.45336-0026WO1 providing low conspicuity lenses that do not make the user feel self-conscious during everyday use.

[0014] While the embodiments below feature eyeglass lenses, implementations using contact lenses are also possible.

[0015] Other features and advantages will be apparent from the disclosure below, the drawings, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG.1A shows a pair of spectacles containing ophthalmic lenses for treating myopia and reducing myopia progression.

[0017] FIG.1B shows a portion of an array of scattering centers for the ophthalmic lenses shown in FIG.1A.

[0018] FIG.1C shows scattering centers with random displacements from uniform spacing.

[0019] FIG.2A shows an example of a pre-edged spectacle lens for treating myopia and managing myopia progression that includes a light diffusion area with a transition zone.

[0020] FIG.2B is a plot showing the density of scattering centers through an example light diffusion area as a function of radius for the spectacle lens shown in FIG.2A.

[0021] FIG.2C is a plot showing the density of scattering centers through another example light diffusion area as a function of radius for the spectacle lens shown in FIG.2A.

[0022] FIG.2D is a plot showing the density of scattering centers through yet another example light diffusion area as a function of radius for the spectacle lens shown in FIG.2A.

[0023] FIG.2E is a plot showing the density of scattering centers through a further example light diffusion area as a function of radius for the spectacle lens shown in FIG.2A.

[0024] FIG.2F is a plot showing the density of scattering centers through a yet further example light diffusion area as a function of radius for the spectacle lens shown in FIG.2A.

[0025] FIG.3A shows another example of a pre-edged spectacle lens for treating myopia and reducing myopia progression that includes a light diffusion area with a transition zone.

[0026] FIG.3B is a plot showing the density of scattering centers through an example light diffusion area as a function of radius for the spectacle lens shown in FIG.3A.

[0027] FIG.4A shows a further example of a pre-edged spectacle lens for treating myopia and reducing myopia progression that includes a light diffusion area with a transition zone.Attorney Docket No.45336-0026WO1

[0028] FIG.4B is a plot showing the density of scattering centers through an example light diffusion area as a function of radius for the spectacle lens shown in FIG.4A.

[0029] FIG.4C is a plot showing the density of scattering centers through an example light diffusion area as a function of radius for the spectacle lens shown in FIG.4A. The radial direction is orthogonal to the radial direction shown in FIG.4B.

[0030] FIGS.5A-5B and 6A-6B show an example of a scattering center pattern of a light scattering area that includes a transition zone

[0031] FIG.7A shows a cross-sectional view of an example lens with scattering centers formed from protuberances on a surface of the lens.

[0032] FIG.7B shows a cross-sectional view of an example lens with scattering centers formed from recesses on a surface of the lens.

[0033] FIG.7C shows a cross-sectional view of another example lens with scattering inclusions between opposing surfaces of the lens.

[0034] In the drawings, like reference numbers denote like elements. DETAILED DESCRIPTION

[0035] Referring to FIG.1A, a pair of spectacles 100 for treating myopia and reducing myopia progression include a pair of lenses 110a and 110b edged and mounted in eyeglass frames 101. Each lens includes a light diffusion area 120 that covers a first portion 150 of the lens for the wearer’s distance vision and near vision and a second portion of the lens corresponding to the wearer’s peripheral visual field. First portion 150 encompasses a central point 152 of each lens that can correspond to the location where the wearer’s visual axis intersects the lens when the wearer is looking straight ahead. The second portion corresponds to a light diffusion area 160. An edge portion 170 of the lens surrounding the light diffusion area 120 is clear, although in certain examples the light diffusion area can extend to the frames 101. Generally, lenses 110a and 110b can be plano lenses, single vision lenses (e.g., with positive or negative power) or multivision lenses (e.g., bifocals or progressive lenses).

[0036] Generally, the scattering center patterns within the light diffusion area 160 can vary. In some examples, at least a portion of the light diffusion area 160 can include a uniform scattering center pattern having scattering centers with the same shape and size, as depicted in FIG.1B, which shows a portion 162 of the light diffusion area 160 in lens 110a. In general, each scattering center 210 can have the same size and shape, e.g., a circle with diameter d, and spacing, e.g., a rectangular grid with spacing Dxin the x-direction and DyinAttorney Docket No.45336-0026WO1 the y-direction. Typically, smaller scattering center spacing will result in greater contrast reduction (provided adjacent scattering centers do not overlap or merge).

[0037] In general, Dx and Dy are in a range from about 0.05 mm (e.g., 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 (e.g., 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, scattering center spacing can be 0.55 mm, 0.365 mm, or 0.240 mm.

[0038] In general, the scattering centers are spaced so that, collectively, the scattering centers provide sufficient forward scattering to reduce contrast between adjacent cone photoreceptors at the wearer’s retina, slowing progression of myopia. In general, scattering centers 210 can be provided by forming protrusions and / or recesses on one or both surfaces of each lens and / or by forming scattering inclusions in the lens material itself.

[0039] While the scattering centers shown in FIG.1B are arranged with equal spacing in the x- and y-directions, more generally, spacing in each direction can be different. Furthermore, scattering centers can be arranged on grids that are not square. For example, hexagonal or circular grids can be used. Non-regular arrays are also possible, e.g., random or semi-random scattering center placement may be used. In the case of a random pattern, spacing Dx in the x-direction and spacing Dy in the y-direction would be the average separation of the scattering centers in x- and y-directions, respectively. In a circular pattern, the spacing can measure the distance along the arc connecting the center of scattering centers. Alternatively, or additionally, an angular difference between scattering centers at substantially the same radial distance from the center of the lens 110 can measure the spacing, e.g., about one scattering center per degree for a given radius.

[0040] In some examples, the scattering center pattern includes randomly displaced scattering centers with respect to a regular array. Introducing random displacements can reduce optical effects associated with regularly spaced scattering centers, such as starburst- like glare. See, e.g., https: / / www.slrlounge.com / diffraction-aperture-and-starburst-effects / which illustrates the starburst effect as it relates to photography. Accordingly, including random displacements in scattering center patterns can provide the user with a more comfortable experience compared to similar scattering center patterns in which the scatteringAttorney Docket No.45336-0026WO1 centers are uniformly spaced. Alternatively, or additionally, randomization of the scattering center pattern can reduce the optical effects (e.g., diffractive or interference effects) that manifest in reflected light, reducing the noticeability of the scattering center patterns to observers.

[0041] Random displacements are illustrated in FIG.1C, which shows scattering centers 201a-201e positioned with respect to an array lattice in which adjacent lattice sites are spaced at a distance Dx from each other in the x-direction and at a distance Dy from each other in the y-direction. As illustrated, Dx= Dy, however, more generally, the vertical and horizontal lattice spacing can be different.

[0042] For each scattering centers, the x displacement ^x = Ax∙Dx∙RN[0,1] and the y displacement ^y = Ay∙Dy∙RN[0,1] where Ax and Ay are jitter amplitudes between 0 and 1 in the x- and y-directions, respectively, which may be the same or different. RN[0,1] is a random number between 0 and 1.

[0043] Scattering centers size can also vary. In some examples, random variation in the size of the scattering centers can reduce optical effects associated with an array of uniformly sized scattering centers, such as glare. For example, as illustrated in FIG.1C, the radial dimension of each scattering centers can vary from a nominal scattering centers radius, r0. As illustrated, scattering centers 201d has nominal scattering centers radius r0, while scattering centers 201b and 201e have radii rb and re, respectively that are both larger than r0 and rb ≠ re. Scattering centers radius can be set according to a formula ri= r0+ ^r, where ^r = Ar∙r0∙RN[0,1], in which i refers to the i-th scattering centers and Aris the scattering center radius jitter amplitude which is set to a value between 0 and 1.

[0044] More generally, while the example above refers to scattering center radius of a nominally circular scattering centers, jitter can be applied to other scattering center size parameters depending on the application. For example, jitter can be applied to scattering center volume or a single scattering center dimension (e.g., x-dimension or y-dimension).

[0045] In some examples, scattering center patterns can include both random jitter in scattering center placement and random jitter in scattering center size. In certain examples, the scattering center pattern in the light diffusion area 160 can feature varying scattering center density, spacing, size, or combination of one or more of these.

[0046] Scattering centers can be designed to deliver reduced narrow angle scattering and increased wide angle scattering to create an even light distribution on a retina, e.g., a low contrast signal, while preserving acuity through geometry of scattering centers. For example,Attorney Docket No.45336-0026WO1 the scattering centers can be designed to generate significant wide forward angle scattering (e.g., such as more than 10%, 20% or more, 30% or more, 40% or more, 50% or more, deflected by more than 2.5 deg.). Narrow angle forward scattering, i.e., within 2.5 deg., can be kept relatively low (e.g., 50% or less, 40% or less, 30% or less, 20% or less).

[0047] In general, the dimension of the scattering centers may be the same across each lens or may vary. For example, the dimension may increase or decrease as a function of the location of the scattering center, e.g., as measured from the clear central aperture and / or as a function of distance from an edge of the lens. In some examples, the scattering center dimensions vary monotonically as the distance from the center of the lens increases (e.g., monotonically increase or monotonically decrease). In some cases, a monotonic increase or decrease in dimension includes varying the diameter of the scattering centers linearly as a function of the distance from the center of the lens.

[0048] In general, as noted above, the scattering centers are arranged so that the light diffusion area 160 includes a maximum scattering (MS) zone and a transition zone, which provides scattering at a lower level than the maximum scattering zone. The zones can be provided by varying a density of scattering centers, a size of the scattering centers, a shape of the scattering centers, and / or a refractive index of the scattering centers.

[0049] The transition zone generally features a scattering center pattern that scatters incident light less than the scattering center pattern in MS zone, providing a transition in the scattering strength of the lens from a low scattering area or the clear aperture to the MS zone. The transition zone can improve the visual experience of the ophthalmic lens with scattering center pattern for the wearer, as compared with comparable lenses having a light diffusion area composed only of the MS zone or with a relatively small transition zone, providing a more comfortable wearing experience. This can be important for children, where the likelihood that a child will regularly wear spectacles featuring such lenses for extended periods depends on the child’s comfort level.

[0050] The scattering center pattern can be selected to provide the weakest scattering closest to a central point of the lens or a clear aperture at or near the central point of the lens, with the scattering strength increasing with increasing radial distances through the transition zone.

[0051] The scattering of light depends on the size of scattering particles (R), and the wavelength of light (λ). In each scattering pattern, the scatterer’s size – at least in part – defines the scattering criteria. When scatterer size is significantly greater than wavelength, the criteria is Geometric Scattering. In this case, all wavelengths are equally scattered, whichAttorney Docket No.45336-0026WO1 produces the white clouds that we observe in the sky. When the scatterer size is at the same order of wavelength, then Mie scattering is the criteria for the scattering pattern. In this case, red light scatters more than blue light. Lastly, when the scatterer size is significantly smaller than wavelength, then Rayleigh scattering occurs and, in this case, blue light scatters more than red light. The scattering center pattern can be selected depending on the application to provide geometric scattering, Mie scattering, and / or Rayleigh scattering.

[0052] In general, the scattering center patterns in the ophthalmic lens treatment zone can be selected based on a variety of design parameters to provide a desired degree of light scattering on the user’s retina. Generally, these design parameters include the scattering center density, size, depth, and shape, and the refractive index, for example. Ideally, the scattering center patterns are selected to provide high visual acuity on the fovea and reduced image contrast on other parts of the retina with sufficiently low discomfort to the wearer to allow for extended, continuous wear. For instance, it can be desirable for children to be comfortable wearing the spectacles for most, if not all, of a day. Alternatively, or additionally, scattering center patterns can be designed for specific tasks, especially high- contrast tasks which are believed to strongly stimulate eye length growth, e.g., video gaming, reading or other wide angle, high contrast image exposure. For example, in such situations (e.g., where the user experiences high contrast in their peripheral vision and / or situations that do not require the wearer to move and to orient themselves using peripheral vision), the scattering intensity and scatter angle in the periphery can be increased, while considerations of consciousness and self-esteem may be less of a concern. This can lead to a higher efficiency in peripheral contrast reduction in such high contrast environment.

[0053] In some examples, the size of the scattering centers can be selected to range from relatively small scatterers that have relatively wide angle scattering to larger scattering centers that create relatively small angle scattering but scatter light more strongly (i.e., the intensity of scattered light is higher) than the small scatterers.

[0054] It is believed that reduced image contrast on the fovea of the wearer’s eye is more efficient at controlling eye growth than reducing image contrast on other parts of the user’s retina. Accordingly, the scattering center pattern can be tailored to reduce (e.g., minimize) light scattered into the wearer’s fovea, while relatively more of the light on other parts of the retina is scattered light. Because the density of cone photoreceptors is very high at the fovea and the size of cones are smaller at the fovea compared to other eccentricities at the retina, the scattering center patterns and transition zones can be tailored to match the increase in size of cones from the fovea to periphery. The amount of scattered light on the fovea can beAttorney Docket No.45336-0026WO1 affected by the size of a clear aperture, but also by the nature of the scattering centers, especially those closest to the clear aperture. In some cases, for example, the scattering centers closest to the central point of the lens can be designed for less efficient light scattering than those further away. Alternatively, or additionally, in some examples, scattering centers closest to the central point can be designed for smaller angle forward scattering than those further away.

[0055] In some examples, the different zones are provided by a variation of the scattering center density radially from a central point of the lens. For instance, referring to FIG.2A, an example pre-edged ophthalmic lens 200 lens suitable for spectacles 100 has a light diffusion area 160 that includes a maximum scattering (MS) zone 220 surrounding a transition zone 215. FIG.2B shows a plot of scattering center density as a function of radius from central point 152 outward. The density of the scattering centers increases linearly from central point 152 to a radius RT, where it reaches the maximum scattering center density at the boundary of the MS zone 220 (see line segment 211). The scattering center density is constant in the MS zone 220, which extends to a radius RMAX (see line segment 221).

[0056] Generally, RMAX is sufficiently large so that the light diffusion area encompasses the wearer’s peripheral visual field and RT is sufficiently large so that the wearer experiences a gradual transition from relatively clear vision at the central point 152 to the reduced contrast and / or visual acuity associated with the scattering centers in the MS zone 220.

[0057] In some examples, RMAX is 20 mm or more (e.g., 22 mm or more, 25 mm or more, 28 mm or more, 30 mm or more, 32 mm or more, 35 mm or more, 38 mm or more, 40 mm or more). RT is 15 mm or more (e.g., 16 mm or more, 17 mm or more, 18 mm or more, 19 mm or more, 20 mm or more, 22 mm or more, 25 mm or more, 28 mm or more, 30 mm or more, 32 mm or more, 35 mm or more). RMAX – RT can be in a range from 1 mm to 20 mm (e.g., 2 mm or more, 3 mm or more, 4 mm or more, 5 mm or more, 6 mm or more 7 mm or more, 8 mm or more 9 mm or more, 10 mm or more, such as 18 mm or less, 15 mm or less, 12 mm or less).

[0058] The MS zone 220 can occupy 5% or more (e.g., 10% or more, 12% or more, 15% or more, 18% or more, 20% or more, 22% or more, 25% or more, 28% or more, 30% or more, 32% or more, 35% or more, 38% or more, 40% or more, 45% or more, 50% or more, such as 80% or less, 70% or less, 60% or less) of the area of the light diffusing area 160. The transition zone 215 can occupy 20% or more (e.g., 22% or more, 25% or more, 28% or more, 30% or more, 32% or more, 35% or more, 38% or more, 40% or more, 45% or more, 50% orAttorney Docket No.45336-0026WO1 more, such as 95% or less, 90% or less, 80% or less, 70% or less, 60% or less) of the area of the light diffusing area 160.

[0059] Scattering center density can be calculated in various ways. For example, the scattering center density can be represented as a number density which refers to the number of scattering centers in a unit area, yielding the units of inverse area, e.g., mm-2. An average number density can be calculated for non-uniform scattering center patterns, e.g., non- uniform spacing, by dividing the total number of scattering centers by the total area of a region.

[0060] Generally, the scattering center pattern of a light diffusion area will have a number density in a range from 0.1 / mm2to 20 / mm2(e.g., 0.2 / mm2or more, 0.5 / mm2or more, 0. 8 / mm2or more, 1 / mm2or more, 1.5 / mm2or more, 2 / mm2or more, 3 / mm2or more, 4 / mm2or more, 5 / mm2or more, 6 / mm2or more, 7 / mm2or more, 8 / mm2or more, such as 15 / mm2or less, 12 / mm2or less, 10 / mm2or less).

[0061] The scattering center density can also (or alternatively) be represented by an areal density, which refers to the fraction (e.g., percentage) of the area (in the x-y plane) of a region of the lens occupied by the scattering centers. In certain examples, the areal density of the scattering centers can be in a range from 5% to 80% (e.g., 10% or more, 12% or more, 15% or more, 18% or more, 20% or more, 22% or more, 25% or more, 28% or more, 30% or more, 32% or more, 35% or more, 38% or more, 40% or more, 45% or more, such as 70% or less, 60% or less, 50% or less).

[0062] Generally, for a spectacle lens, the scattering center density is calculated for areas of 1 mm2or more.

[0063] While the scattering center density increases linearly from the central point 152 to MS zone 220 for the scattering center distribution depicted in FIG.2B, in other examples, non-linear variations in scattering center density are possible. An example is shown in FIG. 2C, in which the scattering center density increases non-linearly as a function of radius (see line segment 212).

[0064] While the scattering center density increases monotonically from the central point 152 to MS zone 220 for the scattering center distribution depicted in FIG.2C, in other examples, non-monotonic variations in scattering center density are possible. For example, referring to FIG.2D, in some examples, the radial density distribution can include a local maximum within transition zone 215.

[0065] In some examples, the transition zone 215 can include annular portions of constant scattering center density. Referring to FIG.2E, a transition zone can includeAttorney Docket No.45336-0026WO1 multiple portions 214 of constant scattering center density, where the density in each successive portion increases as the radial distance from the central point 152 increases. In this example, the portion closest to the central point 152 extends to a radius RTa and has the lowest scattering center density, the next portion extends from RTato RTband has the next lowest scattering center density, the third portion extends to RTc, and the fourth to RTd. Generally, the radial dimension of each portion can be the same or different as other portions. The portions can have a radial dimension in a range from 1 mm to 10 mm (e.g., 2 mm or more, 3 mm or more, 4 mm or more, 8 mm or less, 7 mm or less, 6 mm or less, 5 mm or less). While the example in FIG.2E depicts four portions in the transition zone, more generally, transition zones can have fewer than four portions (e.g., 2 or 3) or more than four (e.g., 5, 6, 7, 8 or more).

[0066] While the foregoing examples each depict the maximum scattering zone 220 as being the outermost zone of the light diffusion area 160, in some examples, a lens can include a further zone outside the MS zone 220 that has a scattering center density lower than that of the maximum scattering zone. For example, as shown in FIG.2F, in certain examples, a lens includes a light scattering area with an outermost area that has a scattering center density that decreases with increasing radius outside of the MS zone. In this example, the MS area extends to a radius RM and the outmost area extends from RM to RMAX. Generally, RMAX – RM can be in a range from 1 mm to 10 mm (e.g., 2 mm to 5 mm).

[0067] In some examples, the light diffusion area surrounds a clear aperture free from scattering centers. For example, referring to FIG.3A and FIG.3B, an example pre-edged lens 300 includes a clear aperture 320 (i.e., free of scattering centers) surrounded by a transition zone 310, which is surrounded by MS zone 220. The clear aperture 320 encompasses central point 152 and can coincide with the wearer’s on-axis viewing position. Generally, the clear aperture 320 provides the wearer with a viewing cone for which their visual acuity may be optimally corrected (e.g., to 20 / 15 or 20 / 20). The size of the clear aperture 320, as measured by a radial dimension RAas shown in FIG.3B, may vary. In some examples, the aperture has a radius in a range from 0.5 mm (e.g., 0.75 mm or more, 1 mm or more, 1.5 mm or more, 2 mm or more, 2.5 mm or more) to 10 mm (e.g., 8 mm or less, 6 mm or less, 5 mm or less, 4 mm or less, 3 mm or less, 2 mm or less).

[0068] While the clear aperture 320 is circular, non-circular (e.g., elliptical, polygonal, teardrop, irregular) apertures are also possible. For non-circular apertures, the radial dimension refers to the maximum radial dimension measured from the central point 152.Attorney Docket No.45336-0026WO1

[0069] The clear aperture 320 can subtend a solid angle 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. The solid angles subtended in the horizontal and vertical viewing planes may be the same or different.

[0070] In general, any of the example scattering center distributions described herein can include one or more clear apertures.

[0071] In the foregoing examples, the light scattering area is depicted as being rotationally symmetric about the central point 152, i.e., the radial scattering center distribution is the same along all radial directions, the MS zone is annular, and the transition zone is annular or circular. However, more generally, non-radially symmetric distributions are possible. For example, referring to FIGS.4A – 4C, in some examples, a pre-edged lens 400 includes a light diffusion area 160 that includes an elliptical transition zone 410 surrounded by a maximal scattering zone 420. Here, the elliptical transition zone extends to a radius R1T in the x-direction and to a radius RT2 in the y-direction, where RT1 > RT2. In both directions, the scattering center density increases linearly to the MS zone 420, but the density increases more rapidly along the y-direction (compare the slope of line segment 411 to line segment 412). The radial dimension of the ms zone 420 is larger in the y-direction than in the x-direction (compare line segment 421 to segment 422). Here, the x-direction can correspond to the horizontal direction in a pair of spectacles.

[0072] More generally, the transition zone can have other non-circular shapes (e.g., polygonal, teardrop, irregular). Moreover, in some examples, the light diffusion area 160 can be non-circular too. For examples in which the transition zone and / or MS zone is non- circular, the example radial dimensions described above can correspond to the radius in the direction along which the radial dimension is maximum (e.g., the x-direction for elliptical transition zone 410 shown in FIG.4A).

[0073] In some examples, as an alternative (or in addition) to the density of scattering centers, the transition zone can be provided by a change in the optical properties of the scattering centers. For instance, scattering center patterns can feature a variation in scattering efficiency of the scattering centers (e.g., due to a variation in the refractive index mismatch and / or shape of each scattering centers).

[0074] In general, the coverage of a lens by scattering centers can vary depending on the implementation. Here, coverage refers to the proportion of the lens’s total area, as projectedAttorney Docket No.45336-0026WO1 onto the x-y plane that corresponds to scattering centers. The spatial density of scattering centers in the clear central, transition, and peripheral zones can determine the total coverage. Typically, a lower scattering center coverage will yield lower scattering than higher scattering center coverage (assuming individual scattering centers are discrete, e.g., the scattering centers do not merge to form larger scattering centers). Scattering center coverage can vary from 10% or more to about 75%. For example, scattering center coverage can be 15% or more, 20% or more, 25% or more, 30% or more, 35% of more, 40% or more, 45% or more, such as 50% or 55%). Scattering center coverage can be selected according to a comfort level of a user, e.g., to provide a level of peripheral vision sufficiently comfortable that the wearer will voluntarily wear the spectacles for extended periods (e.g., all day).

[0075] While the scattering centers 210 are depicted as having circular footprints in FIG. 2A, more generally the scattering centers can have other shapes. For example, the scattering centers can be elongated in one direction (e.g., in the x-direction or y-direction), such as in the case of elliptical scattering centers. In some implementations, the scattering centers are random in shape.

[0076] It is believed that light from a scene that is incident on the lenses in reduced contrast areas, e.g., the transition and MS zones, between the scattering centers contributes to an image of the scene on the user’s retina, while light from the scene incident on the scattering centers does not. Moreover, the light incident on the scattering centers is still transmitted to the retina, so has the effect of reducing image contrast without substantially reducing light intensity and light transmission to the retina. Accordingly, it is believed that the amount of contrast reduction in the user’s peripheral field of view is correlated to (e.g., is approximately proportional to) the proportion of the surface area of the reduced-contrast areas covered by the scattering centers. Generally, scattering centers occupy at least 10% (e.g., 20% or more, 30% or more, 40% or more, 50% or more, such as 90% or less, 80% or less, 70% or less, 60% or less) of the area (as measured in the x-y plane) of a light diffusion area.

[0077] In general, the scattering center pattern reduces the contrast of images of objects when wearers look through the treatment zone of the lens (Transition zone, MS zone) without significantly degrading the viewer’s visual acuity in this region. Here, treatment zone refers to the field of vision outside of the field of the clear, central zone. Image contrast in these regions can be reduced by 20% or more (e.g., 25% or more, 30% or more, 40% or more, 45% or more, 50% or more, 60% or more, 70% or, more, 80% or more) relative to an image contrast viewed using the clear vision zone of the lens as determined. Contrast reduction mayAttorney Docket No.45336-0026WO1 be set according to the needs of each individual case. It is believed that a typical contrast reduction would be in a range from about 50% to 55%. Contrast reduction of lower than 50% may be used for very mild cases, while subjects who are more predisposed might need a higher than 55% contrast reduction. 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 meaningful contrast reduction.

[0078] Contrast, here, refers to the difference in luminance between two objects within the same field of view. Accordingly, contrast reduction refers to a change in this difference.

[0079] Contrast and contrast reduction may be measured in a variety of ways. In some implementations, contrast can be measured based on a brightness difference between different portions of a standard pattern, such as a checkerboard of black and white squares, obtained through the clear vision zone and scattering center pattern of the lens under controlled conditions.

[0080] Alternatively, or additionally, contrast reduction may 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). For an OTF, contrast is specified for transmission of stimuli in which light and dark regions are sinusoidally modulated at different “spatial frequencies.” These stimuli look like alternating light and dark bars with the spacing between bars varying over a range. For all optical systems the transmission of contrast is lowest for the sinusoidally varying stimuli having the highest spatial frequencies. The relationship describing the transmission of contrast for all spatial frequencies is the OTF. The OTF can be obtained by taking the Fourier transform of the point spread function. The point spread function can be also empirically obtained by imaging a point source of light through the lens on to a detector array and determining how light from a point is distributed across the detector.

[0081] In the event of conflicting measurements, the OTF is a preferred technique.

[0082] In some examples, contrast can be estimated based on the ratio of the area of the lens covered by scattering centers compared to the area of the clear central zone. In this approximation, it is assumed that all the light that hits the scattering centers becomes uniformly dispersed across the entire retinal area, which reduces the amount of light available in lighter areas of an image and adds light to darker areas. Accordingly, contrast reduction may be calculated based on light transmission measurements made through the clear, central zone and scattering center pattern of a lens.Attorney Docket No.45336-0026WO1

[0083] An example scattering center pattern is shown in FIGS.5A and 5B. This example includes a clear aperture 501, a transition zone 510 with scattering centers with density increasing as a function of radius, and a MS zone 520 having uniform scattering center density. For the purposes of illustration, the transition zone 510 has been shaded in FIG.5B to demonstrate where the transition zone 510 ends, as it is not obvious to the naked eye in FIG.5A. When edged into a shape that can fit into a pair of frames, lens 500 can reduce image contrast for a viewer with a relatively inconspicuous appearance.

[0084] The transition zone 510 is shown with more detail in FIG.6A, which shows transition zone 510 at a larger scale and includes annular lines corresponding to annular portions. FIG.6B shows a subsection 601 of the transition zone 510 at larger scale still, showing six annular portions. As is evident in this figure, the scattering centers are smallest in the innermost portion and increase in size monotonically with increasing radius.

[0085] In general, the scattering centers can be provided as protuberances and / or recesses on one or both surfaces of each lens, and / or as scattering inclusions in the lens material itself. For example, with reference to FIG.7A, a lens 700 includes a scattering center pattern formed from protuberances 702 on a convex surface 704 of a lens body 701. The protuberances can be formed from an optically transparent material having a similar refractive index to the underlying lens (e.g., 1.60 for polycarbonate). For example, in examples where the lenses are formed from polycarbonate (PC), the protuberances can be formed from a polymer having a similar refractive index to the PC, such as from light- activated polyurethane or epoxy-based plastics. In addition to PC, the lenses themselves can also be made from allyl Di glycol carbonate plastic, a urethane-based monomer or other impact resistant monomers. Alternatively, lenses can be made from one of the more-dense high-refractive index plastics with an index of refraction greater than 1.60. In some implementations, the lenses are made from optically transparent materials with lower index of refraction (e.g., CR39 is at 1.50, Trivex is at 1.53).

[0086] In some examples, the protuberance material is selected to have a refractive index that is within 0.1 (e.g., within 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., as measured at one or more wavelengths in the visible light range).

[0087] In certain implementations, larger refractive index mismatches (e.g., more than 0.1) are possible. For example, the protuberance material can be selected to have a refractiveAttorney Docket No.45336-0026WO1 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, such as up to about 0.4).

[0088] A further example is shown in FIG.7B, in which a lens 710 includes scattering centers formed from recesses 712 formed in a concave surface of a lens body 711. Recesses can be formed using a variety of techniques, such as etching (e.g., physical etching or chemical etching) or ablating material from the lens surface (e.g., using laser radiation or a molecular or ion beam). In some examples, recesses are formed when molding the lens. The recesses can, in some cases, each correspond to a region of the lens surface where sufficient material is removed to roughen the surface so that the lens surface scatters, rather than refracts, incident light.

[0089] In yet another example, a lens 720 includes scattering centers 722 that are composed of inclusions in the lens body 721. Scattering centers that are inclusions are typically formed from a material that has a refractive index mismatch from the bulk lens material. For example, transparent beads of appropriate size can be dispersed in the lens material when the lens is molded, where the refractive index of the bead material and bulk lens material differ. A clear aperture can be formed from bulk lens material only.

[0090] In general, the refractive index of each scattering center can be the same or different. For example, where the scattering centers are each formed from the same material, each one can have the same refractive index. Alternatively, in some implementations, the refractive index can vary from scattering center to scattering center or between different groups of scattering centers. For example, in certain implementations, the refractive index mismatch between the scattering centers and the lens bulk material can increase as the radial distance from the lens axis increases in order to increase the amount of light scattering from each scattering center as the radial distance from the lens axis increases.

[0091] In some instances, scattering centers can be formed from materials that absorb at least some light incident thereon, such as dyes. The materials can be selected to absorb broadband visible light, or absorb light only at certain wavelengths (e.g., absorb a short wavelength component or long wavelength component). It is believed that light absorptive materials can help reduce glare and / or provide another design parameter for shaping the point spread function of the scattering centers. In some implementations, exposure to radiation can change the lens material from transparent to absorptive at certain wavelengths. For instance, the exposing radiation can burn the lens material in order to form light absorbing centers in the lens material or on its surface.Attorney Docket No.45336-0026WO1

[0092] In general, scattering centers can be formed from lenses in a variety of ways. US 10,884,264 B2 discloses such methods and is incorporated herein by reference in its entirety.

[0093] In some examples, embedded scattering centers can be formed using a process that selectively induces a refractive index change in the lens bulk material. For example, exposure to a laser beam can cause a local change in the refractive index of bulk the lens material, e.g., through a photochemical and / or photothermal interaction.

[0094] Generally, positive power, negative power, or unpowered lenses can be used.

[0095] Lenses 700, 710, and 720 can include one or more coatings on either or both surfaces. Optical coating 606 can perform one or more functions, such as antireflection, spectral filtering (e.g., UV filtering), or providing a protective hardcoat.

[0096] In some examples, contrast reduction is produced by other diffusing structures, such as a roughened surface. Holographic diffusers or ground glass diffusers may be used. In some implementations, a diffuser may be provided by a film that is laminated onto a surface of the lens.

[0097] Generally, the refractive index mismatch between the lens material and the scattering center material affects the amount of light scattered at each protuberance, e.g., as calculated using a point spread function. Typically, the larger the refractive index mismatch between the materials, the more incident light will be scattered. Accordingly, refractive index mismatch can be used as a design parameter with which to optimize the scattering properties of the scattering centers.

[0098] In general, a variety of different metrics can be used to evaluate the performance of scattering center patterns to optimize the scattering magnitude and angle to be used in optical solutions for myopia management. For example, scattering center patterns can be optimized empirically, e.g., based on physical measurements of lenses with different scattering center patterns. For example, wide-angle 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 meters can be used, e.g., a BYK-Gardner haze meter (such as the Haze-Gard Plus instrument) that measures how much light is totally transmitted through a lens, the amount of light transmitted undisturbed (e.g., within 0.5 deg.), how much is deflected more than 2.5 deg., and clarity (amount within 2.5 deg.). Narrow- angle scattering can be used to represent clarity and wide-angle scattering can be used to represent wide-angle scattering in materials. Other equipment can also be used to characterize light scattering for purposes of empirically optimizing scattering patterns. ForAttorney Docket No.45336-0026WO1 example, equipment that measures light diffusion by measuring light in annular ring around 2.5 deg. can be used (e.g., equipment from Hornell).

[0099] In some implementations, the haze of the transition zone can be in a range from 1% to 20% (e.g., 1% or more, 2% or more, 3% or more, 4% or more, 5% or more, 6% or more, 7% or more, 8% or more, 9% or more, such as 18% or less, 15% or less, 14% or less, 13% or less, 12% or less, 11% or less, 10% or less; e.g., from 3% to 15%, from 5% to 10%). In certain implementations, the haze of the MS zone can be in a range from 5% to 50% (e.g., 8% or more, 10% or more, 12% or more, 15% or more, such as 40% or less, 30% or less, 25% or less, 20% or less, 15% or less; e.g., from 5% to 25%, from 10% to 25%).

[0100] Alternatively, or additionally, scattering center patterns can be optimized by computer modelling software (e.g., Zemax or Code V).

[0101] In some examples, scattering center patterns can be designed based on optimization of a point spread function, which is a representation of an image of the scattering center on the retina. For example, the size, shape, and spacing of the scattering centers can be varied to evenly spread illumination of retina such that the retina outside of fovea is homogeneously blanketed with scattered light to reduce (e.g., minimize) contrast at this region of the retina.

[0102] Alternatively, or additionally, scattering center patterns can be designed based on optimization of a modulation transfer function, which refers to the spatial frequency response of the human visual system. For instance, the size, shape, and spacing of the scattering centers can be varied to smoothen attenuation of a range of spatial frequencies. Design parameters of the scattering center pattern can be varied in order to increase or decrease certain spatial frequencies as desired. Generally, the spatial frequencies of interest for vision are 18 cycles per deg. on the fine side, and 1.5 cycles per deg. on the course side. Scattering center patterns can be designed to provide increased signal at certain subsets of spatial frequencies within this range.

[0103] The aforementioned metrics can be used to evaluate scattering center patterns based on the size and / or shape of the scattering centers, both of which can be varied as desired. For example, the scattering centers can be substantially round (e.g., spherical), elongated (e.g., ellipsoidal), or irregularly-shaped. Generally, the scattering centers have a dimension (e.g., diameter, as depicted in FIGS.1B and 1C) that is sufficiently large to scatter visible light, yet sufficiently small so as not to be resolved by the wearer during normal use. For example, the scattering centers can have a dimension (as measured in the x-y plane) in a range from about 0.001 mm or more (e.g., about 0.005 mm or more, about 0.01 mm or more,Attorney Docket No.45336-0026WO1 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).

[0104] Note that for smaller scattering centers, e.g., having a dimension that is comparable to the wavelength of light (e.g., 0.001 mm to about 0.05 mm), the light scattering may be considered Rayleigh or Mie scattering. For larger scattering centers, e.g., about 0.1 mm or more, light scattering may be due to geometric scattering.

[0105] As noted above, in some examples, a lens can have the smallest scattering centers closest to the center of the lens, and the size of the scattering centers can increase as the radial distance from the center increases. In some cases, the distribution of scattering center sizes can be such that Rayleigh / Mie scattering dominates nearer the lens center, while geometric scattering dominates towards the periphery. For example, scattering centers closest to the lens center can have a maximum dimension in a range from 0.01 mm to 0.1 mm (e.g., 0.01 mm to 0.05 mm, 0.25 mm to 0.5 mm), while the scattering centers furthest from the lens center having a dimension in a range from 0.25 mm to 1 mm (e.g., 0.3 mm to 0.8 mm, 0.4 mm to 0.75 mm, 0.5 mm to 0.6 mm). The dimension of the scattering centers can increase monotonically (e.g., increase linearly, increase geometrically) from the lens center outwards. The sizes of scattering centers and / or the increase in size can be the same in any direction from the lens center or can differ along different radial directions.

[0106] Generally, ophthalmic lenses can be clear or tinted. That is, the lenses may be optically transparent to all visible wavelengths, appearing clear and / or colorless, or may include a spectral filter, appearing colored. For example, ophthalmic lenses may include a filter that reduces the amount of red light transmitted to the wearer. It is believed that excessive stimulation of L cones in a person’s eye (especially in children), may result in non- optimal eye lengthening and myopia. Accordingly, spectrally filtering red light using the ophthalmic lenses may further reduce myopia in a wearer.

[0107] Spectral filtering may be provided by applying a film to a surface of the lenses. Films may be applied by physically depositing material onto a lens surface, coating a layer of material on the surface, or laminating a preformed film onto the surface. Suitable materials include absorptive filter materials (e.g., dyes) or multilayer films, providing interferenceAttorney Docket No.45336-0026WO1 filtering. In some implementations, spectral filtering may be provided by including a filtering material in the lens material itself and / or including a filtering material in the material used to form the protuberance.

[0108] While the example ophthalmic lenses described above are spectacle lenses, more generally, the principles described herein can be implemented in other types of ophthalmic lenses, such as contact lenses and intraocular lenses.

[0109] Among other embodiments, the disclosure features the following embodiments, alone and / or in any combination.

[0110] In general, in a first aspect, the disclosure features an ophthalmic lens, including: a lens body having a first curved surface and a second curved surface opposite the first curved surface, the lens body having a central point; a light diffusion area, the light diffusion area comprising a plurality of scattering centers sized and shaped to scatter incident light, a density of the scattering centers varying over the light diffusion area, the light diffusion area including: a first zone surrounding the central point, the first zone having the highest density of scattering centers of the light diffusion area; and a second zone between the first zone and the central point, the second zone having a density of scattering centers lower than the first zone, wherein the second zone extends to a point on the lens 15 mm or more from the central point in at least one radial direction measured from the central point.

[0111] In some implementations, the density of the scattering centers in the second zone increases with increasing distance from the central point along the at least one radial direction.

[0112] In some implementations, the density increases monotonically.

[0113] In some implementations, the density increases linearly.

[0114] In some implementations, the density increases non-linearly.

[0115] In some implementations, the second zone extends to a point on the lens 18 mm or more from the central point in the at least one radial direction.

[0116] In some implementations, the second zone extends to a point on the lens 20 mm or more from the central point in the at least one radial direction.

[0117] In some implementations, the second zone extends to a point on the lens 25 mm or more from the central point in the at least one radial direction.

[0118] The ophthalmic lens further including a clear aperture located at the central point and surrounded by the second, e.g., transition, zone.

[0119] In some implementations, the clear aperture has a radial dimension in a range from 1 mm to 5 mm along the at least one radial direction.Attorney Docket No.45336-0026WO1

[0120] In some implementations, the density is a number density.

[0121] In some implementations, the density is an areal density.

[0122] In some implementations, an average size of the scattering centers in the second zone is smaller than an average size of the scattering centers in the first zone.

[0123] In some implementations, the average size of the scattering centers in the second zone increases along the at least one radial direction.

[0124] In some implementations, the first zone has a haze of 5% or more (e.g., 5% to 30%, 5% to 25%, 5% to 20%, 5% to 15%, 5% to 10%).

[0125] In some implementations, the second zone has a haze of 20% or less (e.g., 1% to 20%, 1% to 15%, 1% to 10%, 1% to 5%).

[0126] In some implementations, the light diffusing area is a circular area.

[0127] In some implementations, the first zone occupies an annular area.

[0128] In some implementations, the second zone occupies an annular area or a circular area.

[0129] In some implementations, a pattern of scattering centers is not continuously rotationally symmetric.

[0130] In some implementations, the scattering centers are on the first curved surface.

[0131] In some implementations, the scattering centers are embedded in a lens material.

[0132] In some implementations, each scattering center has a maximum dimension of 1 mm or less (e.g., 0.8 mm or less, 0.5 mm or less, 0.4 mm or less, 0.2 mm or less, e.g., 0.01 mm or more, 0.03 mm or more, 0.05 mm or more, 0.07 mm or more, 0.1 mm or more, 0.15 mm or more).

[0133] In some implementations, a size of the scattering centers increases monotonically from the central point to the first zone along at least one radial direction.

[0134] In some implementations, the size of the scattering centers increases monotonically from the central point to the first zone along each radial direction.

[0135] In some implementations, the size of the scattering centers increases from a minimum scattering center size in a range from 0.01 mm to 0.05 mm to a maximum scattering center size of 0.1 mm or more (e.g., 0.2 mm or more, 0.3 mm or more, 0.4 mm or more, 0.5 mm or more, 0.6 mm or more, 0.7 mm or more, 0.8 mm or more, 0.9 mm or more, such as 1 mm or less).

[0136] In some implementations, the ophthalmic lens is a spectacle lens.

[0137] In some implementations, the ophthalmic lens is a contact lens.Attorney Docket No.45336-0026WO1

[0138] A number of embodiments are described. Other embodiments are in the following claims.

Claims

Attorney Docket No.45336-0026WO1 WHAT IS CLAIMED IS:

1. An ophthalmic lens, comprising: a lens body having a first curved surface and a second curved surface opposite the first curved surface, the lens body having a central point; a light diffusion area, the light diffusion area comprising a plurality of scattering centers sized and shaped to scatter incident light, a density of the scattering centers varying over the light diffusion area, the light diffusion area comprising: a first zone surrounding the central point, the first zone having the highest density of scattering centers of the light diffusion area; and a second zone between the first zone and the central point, the second zone having a density of scattering centers lower than the first zone, wherein the second zone extends to a point on the lens 15 mm or more from the central point in at least one radial direction measured from the central point.

2. The ophthalmic lens of claim 1, wherein the density of the scattering centers in the second zone increases with increasing distance from the central point along the at least one radial direction.

3. The ophthalmic lens of claim 2, wherein the density increases monotonically.

4. The ophthalmic lens of claim 2, wherein the density increases linearly.

5. The ophthalmic lens of claim 2, wherein the density increases non-linearly.

6. The ophthalmic lens of any one of the previous claims, wherein the second zone extends to a point on the lens 18 mm or more from the central point in the at least one radial direction.

7. The ophthalmic lens of any one of the previous claims, wherein the second zone extends to a point on the lens 20 mm or more from the central point in the at least one radial direction.Attorney Docket No.45336-0026WO1 8. The ophthalmic lens of any one of the previous claims, wherein the second zone extends to a point on the lens 25 mm or more from the central point in the at least one radial direction.

9. The ophthalmic lens of any one of the previous claims, further comprising a clear aperture located at the central point and surrounded by the second zone.

10. The ophthalmic lens of claim 9, wherein the clear aperture has a radial dimension in a range from 1 mm to 5 mm along the at least one radial direction.

11. The ophthalmic lens of claim 1, wherein the density is a number density.

12. The ophthalmic lens of claim 1, wherein the density is an areal density.

13. The ophthalmic lens of any one of the previous claims, wherein an average size of the scattering centers in the second zone is smaller than an average size of the scattering centers in the first zone.

14. The ophthalmic lens of any one of the previous claims, wherein the average size of the scattering centers in the second zone increases along the at least one radial direction.

15. The ophthalmic lens of any one of the previous claims, wherein the first zone has a haze of 5% or more.

16. The ophthalmic lens of any one of the previous claims, wherein the second zone has a haze of 20% or less.

17. The ophthalmic lens of any one of the previous claims, wherein the light diffusing area is a circular area.

18. The ophthalmic lens of claim 17, wherein the first zone occupies an annular area.Attorney Docket No.45336-0026WO1 19. The ophthalmic lens of claim 18, wherein the second zone occupies an annular area or a circular area.

20. The ophthalmic lens of any one of claims 1-16, wherein a pattern of scattering centers is not continuously rotationally symmetric.

21. The ophthalmic lens of claim 1, wherein the scattering centers are on the first curved surface.

22. The ophthalmic lens of claim 1, wherein the scattering centers are embedded in a lens material.

23. The ophthalmic lens of claim 1, wherein each scattering center has a maximum dimension of 1 mm or less.

24. The ophthalmic lens of claim any one of the previous claims, wherein a size of the scattering centers increases monotonically from the central point to the first zone along at least one radial direction.

25. The ophthalmic lens of claim 24, wherein the size of the scattering centers increases monotonically from the central point to the first zone along each radial direction.

26. The ophthalmic lens of claim 24, wherein the size of the scattering centers increases from a minimum scattering center size in a range from 0.01 mm to 0.05 mm to a maximum scattering center size of 0.1 mm or more.

27. The ophthalmic lens of claim 1, wherein the ophthalmic lens is a spectacle lens.

28. The ophthalmic lens of claim 1, wherein the ophthalmic lens is a contact lens.

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