Ophthalmic lens with light scattering for treating myopia

Abstract

The invention relates to an ophthalmic lens with light scattering for treating myopia. An ophthalmic lens, the ophthalmic lens comprising: a lens material having two opposing curved surfaces, the curved surfaces defining a lens axis; and a light scattering region surrounding the clear aperture. The clear aperture and the light scattering region are substantially centered on the lens axis, and the light scattering region has a plurality of spaced apart scattering centers (e.g., on the lens surface and / or embedded in the lens material) that are sized and shaped such that incident light is scattered, such that the incident light is scattered. The scattering centers are arranged in a pattern that includes a random change in pitch between adjacent dots and / or a random change in dot size.

Description

[0001] This application is a divisional application of the patent application with application number 201980016486.9 (international application number PCT / US2019 / 015724) filed on September 1, 2020, with international application date of January 29, 2019, and invention name entitled "Ophthalmic lens with light scattering for treating myopia".

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to Provisional Application No. 62 / 624,038, entitled “Method for Forming an Ophthalmic Lens for Treating Myopia,” filed on January 30, 2018, Provisional Application No. 62 / 663,938, entitled “Ophthalmic Lens with Light Scattering for Treating Myopia,” filed on April 27, 2018, and Provisional Application No. 62 / 671,992, entitled “Ophthalmic Lens with Light Scattering for Treating Myopia,” filed on May 15, 2018. The entire contents of each of these provisional applications are incorporated herein by reference. Technical Field

[0004] The present invention features an ophthalmic lens for treating myopia and reducing the progression of myopia. Background Art

[0005] The eye is an optical sensor in which light from external sources is focused by the lens onto the surface of the retina (an array of wavelength-dependent photoreceptors). 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 nearly optimally focused to produce an inverted image on the retinal surface that corresponds to the external image observed by the eye. In each of the various shapes that the eye lens can adopt, the eye lens optimally or nearly optimally focuses light emitted by or reflected from external objects within a certain distance range from the eye, while focusing less optimally or failing to focus on objects beyond that distance range.

[0006] In individuals with normal vision, the axial length of the eye, or the distance from the lens to the retinal surface, corresponds to the focal length at which distant objects are nearly in optimal focus. The eye of an individual with normal vision focuses on distant objects without neural input to the muscles that apply force to change the shape of the eye's lens, a process known as accommodation. As a result of accommodation, normal individuals focus on relatively close, nearby objects.

[0007] However, many people suffer from eye length-related conditions, such as myopia ("nearsightness"). In myopic individuals, the axial length of the eye is longer than required to focus on distant objects without accommodation. As a result, myopic individuals can see nearby objects clearly, but distant objects are blurry. Although myopic individuals are generally able to accommodate, the average distance at which they can focus objects is shorter than that of individuals with normal vision.

[0008] Typically, infants are born farsighted, with an eye length shorter than required for optimal or near-optimal focus on distant objects without accommodation. During normal development of the eye (called "emmetropization"), the axial length of the eye increases relative to the other dimensions of the eye to a length that provides near-optimal focus of distant objects without accommodation. Ideally, biological processes maintain a near-optimal eye length relative to eye size as the eye grows to its final adult size. However, in myopic individuals, the relative axial length of the eye for the entire eye size continues to increase during development, exceeding the length that provides near-optimal focus of distant objects, resulting in increasingly pronounced myopia.

[0009] Myopia is believed to be influenced by both behavioral and genetic factors. Therefore, myopia can be alleviated through therapeutic devices that address behavioral factors. For example, U.S. Patent Publication No. 2011 / 0313058A1 describes a therapeutic device for treating eye length-related conditions, including myopia. Summary of the Invention

[0010] Eyeglasses and contact lenses are disclosed that reduce signals in the retina responsible for eye length growth. Exemplary embodiments are manufactured using, for example, polycarbonate or Trivex lens blanks that have been treated by applying a pattern of scattering centers or "dots" with a dot-free aperture on the visual axis. The result is reduced contrast in the retinal image, which is believed to reduce eye growth associated with myopia progression. The dot-free aperture on the lens axis allows the user to experience maximum visual acuity when viewing on-axis objects, while viewing objects at the periphery of the user's field of view with reduced contrast and acuity.

[0011] With these glasses, the contrast of the focused image in the peripheral retinal area is reduced compared to images typically used to correct (but not treat) refractive errors. The exact amount of contrast reduction depends on the relative number of dark and light areas in the transmitted image. For the example above, with 24% uniform light dispersion, the maximum contrast reduction would be 48%, where contrast is defined as the difference in illuminance divided by the average illuminance. Experiments have shown that this reduction in contrast in the peripheral retinal area has important implications for ocular physiology related to the mechanisms responsible for controlling eye growth.

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

[0013] In general, in a first aspect, the present invention is characterized by an ophthalmic lens comprising a lens material having two opposing curved surfaces; and a scattering region surrounding a clear aperture, wherein the scattering region has a plurality of spaced-apart scattering centers that are sized and shaped so as to scatter incident light, and the scattering centers are arranged in a pattern that includes irregular variations in the spacing between adjacent scattering centers and / or irregular variations in the size of the scattering centers.

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

[0015] The scatter centers may have sizes that vary randomly from a nominal value, the random variation being equal to or less than the dither amplitude. The dither amplitude may be 0.5 times the nominal value or less (e.g., 0.01 to 0.5, 0.02 or greater, 0.03 or greater, 0.04 or greater, 0.05 or greater, 0.08 or greater, 0.1 or greater, 0.12 or greater, 0.15 or greater, 0.18 or greater, 0.2 or greater, 0.25 or greater, 0.3 or greater, 0.35 or greater, 0.4 or greater).

[0016] The scattering centers may have volumes that vary randomly from a nominal volume, the random variation being equal to or less than the dither amplitude. The dither amplitude may be 0.5 times the nominal volume or less (e.g., 0.01 to 0.5, 0.02 or greater, 0.03 or greater, 0.04 or greater, 0.05 or greater, 0.08 or greater, 0.1 or greater, 0.12 or greater, 0.15 or greater, 0.18 or greater, 0.2 or greater, 0.25 or greater, 0.3 or greater, 0.35 or greater, 0.4 or greater).

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

[0018] The scattering region may include a first scattering region and a second scattering region, the second scattering region being arranged between the clear aperture and the first scattering region, the second scattering region including scattering centers sized and arranged so as to scatter incident light more weakly than the scattering centers of the first scattering region. The lens may have a lens axis, with the aperture and the first and second scattering regions being substantially centered on the lens axis, and the scattering centers in the second scattering region having a size that increases monotonically (e.g., linearly or geometrically) with increasing radial distance from the lens axis. The lens may have a lens axis, with the aperture and the first and second scattering regions being substantially centered on the lens axis, and the scattering centers in the second scattering region having a size and / or volume that varies monotonically (e.g., linearly or geometrically) with increasing radial distance from the lens axis.

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

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

[0021] The scattering center may be in the shape of a substantially circular shape. The scattering center may be in the shape of a logo or an alphanumeric symbol.

[0022] The lens can be a plano lens, a single vision lens or a multifocal lens. The lens can be a spectacle lens or a contact lens.

[0023] The scattering area may be an annular area, and the clear aperture may be a circular aperture.

[0024] In another aspect, the invention features a method of treating an eye length related disease, comprising: identifying an eye length related disease in a patient; and reducing the contrast of an image in the patient's peripheral vision using an ophthalmic lens according to the prior art.

[0025] In another aspect, the invention features a pair of eyeglasses comprising: an eyeglass frame; and a pair of ophthalmic lenses according to the above aspects, each mounted in the frame.

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

[0027] The lens may have optical power to correct the wearer's on-axis vision to 20 / 20 or better through the clear aperture and to 20 / 25 or better for at least a portion of the wearer's peripheral vision through the dot pattern.

[0028] In another aspect, the invention features a method of treating an eye length-related disorder, comprising identifying an eye length-related disorder in a patient; and reducing the contrast of an image in the patient's peripheral vision using the eyewear described above.

[0029] In general, in another aspect, the invention features a method comprising: focusing a laser beam to a focal point; and exposing an ophthalmic lens to the focused laser radiation to form optical scattering features in a pattern on a curved surface of the ophthalmic lens. Exposing the ophthalmic lens comprises inducing relative motion between the laser beam and the lens such that different locations on the lens surface intersect the laser beam at different locations relative to the focal point.

[0030] Implementations of this method may 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 position of the lens surface relative to the focal point. As the distance of the lens surface relative to the focal point increases, the degree of scattering caused by the optical scattering feature can decrease.

[0031] The pattern may include an annular region of optically scattering features surrounding a clear aperture corresponding to the viewing axis of the ophthalmic lens. The optically scattering features may include discrete dots. The dots may be arranged in an array, with each dot spaced 1 mm or less apart, and each dot having a maximum dimension of 0.5 mm or less. The clear aperture may be an area free of dots, having a maximum dimension greater than 1 mm.

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

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

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

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

[0036] During exposure, the laser radiation can be focused to a spot size of about 0.1 mm or less (eg, about 0.05 mm or less, about 0.025 mm or less).

[0037] An ophthalmic lens may be exposed such that each location at the lens surface that is exposed experiences a corresponding discrete exposure of the same duration and the same energy.

[0038] The exposed surface may be a convex surface or a concave surface.

[0039] In general, in another aspect, the invention features 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 cause bubbling of a material forming the ophthalmic lens. Bubbles from the bubbling form scattering centers in the ophthalmic lens. Implementations of the method may include one or more features of the other aspects.

[0040] In general, in another aspect, the invention features a method comprising: simultaneously exposing an ophthalmic lens formed from a lens material to two or more beams of laser radiation such that the two or more beams overlap in a portion of the lens material, the intensity of the laser radiation in the overlapping beams being sufficient to form optical scattering features in the lens material; and varying the positions of the overlapping beams in the lens to form a pattern of optical scattering features in the lens.

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

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

[0043] Laser radiation in overlapping beams can change the refractive index of the lens material by inducing photochemical changes in the lens material.

[0044] Laser radiation in overlapping beams can change the refractive index of the lens material by inducing photothermal changes in the lens material.

[0045] In another aspect, the invention features a pair of eyeglasses including an eyeglass frame and a pair of ophthalmic lenses mounted in the frame, each lens including a pattern distributed across each lens formed using one of the above methods.

[0046] Embodiments of the eyewear may include one or more of the following features and / or other aspects. For example, each pattern may include a region including optically scattering features surrounding a clear aperture that is devoid of scattering features. The dot pattern may reduce the image contrast of an object viewed through the dot pattern by at least 30% (e.g., by at least 35%, by at least 40%, by at least 45%, by at least 50%, by at least 55%, by at least 60%) compared to the image contrast of an object viewed through the clear aperture.

[0047] The lens may have optical power to correct the wearer's on-axis vision to 20 / 20 or better through the clear aperture and to 20 / 25 or better for at least a portion of the wearer's peripheral vision through the dot pattern.

[0048] Among other advantages, the disclosed embodiments feature eyewear that includes features that reduce the signals in the retina responsible for ocular length growth in both eyes without disrupting the user's on-axis vision in either eye. For example, a dot pattern is provided that moderately obscures the wearer's peripheral vision while allowing normal on-axis vision through the clear aperture, enabling all-day, everyday use by the wearer. Compared to approaches involving alternating between different pairs of glasses or the use of eyeglass accessories, the disclosed embodiments can also provide therapeutic benefits to both eyes using only one pair of glasses.

[0049] Furthermore, the dot pattern can be largely unnoticeable to others, particularly if the dot pattern is clear and / or when worn with contact lenses. The subtlety of the dot pattern can lead to more consistent use by some wearers, particularly children, who might otherwise feel self-conscious about using a more conspicuous device on a daily basis (e.g., at school or among peers). For example, a gradient dot pattern can be used to reduce the conspicuousness of the dot pattern to third parties.

[0050] The dot pattern can also be optimized to enhance viewer comfort. For example, the dot pattern can include a transition zone that softens the transition from the lens's clear aperture to the diffuse region in the viewer's field of view. Alternatively or additionally, random dithering can be applied to the dot pattern (e.g., to dot size and / or dot spacing). Such randomization can reduce undesirable optical effects (e.g., diffraction or interference effects) associated with a uniform array of optical features. For example, random dithering can be used to reduce the user's experience of glare. The dot pattern can also be made less conspicuous to third parties by reducing diffraction or interference effects in reflections.

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

[0052] The disclosed embodiments may allow for the efficient and economical formation of dot patterns for mitigating eye elongation on conventional ophthalmic lenses, for example, by forming the dot pattern on a surface or block of the lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1A A pair of spectacles containing ophthalmic lenses for treating myopia is shown.

[0054] Figure 1B Shown Figure 1A Dot pattern on an ophthalmic lens shown.

[0055] Figure 2 The contrast reduction experienced using an exemplary ophthalmic lens for treating myopia is shown.

[0056] Figure 3A A cross-sectional view of exemplary lens material removed from the surface of a lens is shown.

[0057] Figure 3B A cross-sectional view of an exemplary lens having a scattering inclusion between opposing surfaces of the lens is shown.

[0058] Figure 4A and Figure 4B A lens blank is shown having a dot pattern with a transition zone between the clear aperture and the dot pattern.

[0059] Figure 4C Points with random displacements from uniform spacing are shown.

[0060] Figure 5A An exemplary dot pattern is shown having a transition region and uniformly spaced dots.

[0061] Figure 5B An exemplary dot pattern is shown having a transition zone and having dots that are randomly displaced from uniform spacing.

[0062] Figure 5C Another exemplary dot pattern is shown having a transition region and uniformly spaced dots.

[0063] Figure 5D Another exemplary dot pattern is shown having a transition zone and having dots that are randomly displaced from uniform spacing.

[0064] Figure 5E Additional exemplary dot patterns are shown having transition regions and evenly spaced dots.

[0065] Figure 5F Additional exemplary dot patterns are shown having transition zones and having dots that are randomly displaced from uniform spacing.

[0066] Figure 6A An exemplary lens is shown having a graduated dot pattern with varying spacing between adjacent dots.

[0067] Figure 6B An exemplary lens having a graduated dot pattern of varying dot sizes is shown.

[0068] Figure 7A An exemplary lens having a pattern with information encoded by dots of varying sizes is shown.

[0069] Figure 7B An exemplary lens having a pattern with information encoded by dots having different shapes is shown.

[0070] Figure 7C An exemplary lens is shown having a pattern of dots in the form of a logo.

[0071] Figure 8 An exemplary machine reading system is shown.

[0072] Figure 9 Schematic diagram of a laser system used to form recesses on the surface of a lens.

[0073] Figure 10 is a schematic diagram of another laser system for forming recesses on the surface of a lens.

[0074] Figure 11A is a graph showing the change in refractive index of the lens material versus laser intensity.

[0075] Figure 11B is a schematic diagram of a laser system used to form inclusions in bulk material for an exemplary lens. DETAILED DESCRIPTION

[0076] Reference Figure 1A , discloses myopia-reducing eyeglasses 100 that allow for simultaneous treatment of both eyes without substantially compromising clear vision. Furthermore, the eyeglasses are sufficiently robust and unobtrusive to allow the wearer to carry out the same daily activities without the eyeglasses malfunctioning and without becoming self-conscious about their appearance, which is particularly desirable since eyeglasses are often used to prevent children's eyes from elongating.

[0077] Myopia-reducing eyeglasses 100 comprise a pair of frames 101 and ophthalmic lenses 110a and 110b mounted therein. Typically, the ophthalmic lenses can be plano lenses, single-vision lenses (e.g., having positive or negative optical power), or multifocal lenses (e.g., bifocals or progressive lenses). The ophthalmic lenses 110a and 110b each have a clear aperture 120a and 120b, respectively, surrounded by contrast-reducing regions 130a and 130b. The clear apertures 120a and 120b are positioned to coincide with the wearer's on-axis viewing position, while the contrast-reducing regions 130a and 130b correspond to the wearer's peripheral vision. Also refer to Figure 1B , the contrast-reduced regions 130a and 130b are comprised of an array of dots 140 that reduce the contrast of objects in the wearer's peripheral vision by scattering light passing through those regions toward the wearer's eyes. Generally, the dots 140 can be provided by forming protrusions and / or depressions on one or both surfaces of each of the lens in regions 130a and 130b, and / or by forming scattering inclusions in the lens material itself in those regions.

[0078] The size and shape of the clear aperture may vary. Typically, the clear aperture provides a cone of vision for the wearer for which their visual acuity is best corrected (e.g., to 20 / 15 or 20 / 20). In some embodiments, the maximum dimension of the aperture (in the xy plane) is in the range of about 0.2 mm (e.g., about 0.3 mm or greater, about 0.4 mm or greater, about 0.5 mm or greater, about 0.6 mm or greater, about 0.7 mm or greater, about 0.8 mm or greater, about 0.9 mm or greater) 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). Where the aperture is circular, for example, as Figure 1A As shown, this dimension corresponds to the diameter of the circle (i.e. A x = A y ), but non-circular shapes (e.g., ellipses, polygons, A x ≠A y ) of the aperture.

[0079] The clear aperture 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, or about 3 degrees or less) within the observer's field of view. The solid angles subtended in the horizontal and vertical viewing planes can be the same or different.

[0080] Generally, the dot pattern in contrast-reducing regions 130a and 130b can be selected based on a variety of design parameters to provide a desired degree of light scattering on the user's retina. These design parameters typically include, for example, dot density, size and shape, and refractive index, and are discussed in greater detail below. Ideally, the dot pattern is selected to provide high visual acuity at the fovea, reduced image contrast at other parts of the retina, and low enough discomfort for the wearer to allow for extended, continuous wear. For example, for children, it may be desirable to wear glasses comfortably for most, if not all, of the day. Alternatively or additionally, the dot pattern can be designed for specific tasks, particularly those believed to strongly promote eye length growth, such as video gaming, reading, or other wide-angle, high-contrast image exposure. For example, in situations where the user experiences high contrast in their peripheral vision and / or where the wearer is not required to use peripheral vision to move and orient themselves, the intensity and angle of scattering in the periphery may be increased, while concerns about awareness and self-esteem may be reduced. This can result in greater effectiveness of peripheral contrast reduction in such high-contrast environments.

[0081] It can be argued that reducing image contrast at the fovea of ​​a user's eye is less effective at controlling eye growth than reducing image contrast at other parts of the user's retina. Therefore, the dot pattern can be tailored to reduce (e.g., minimize) light scattered into the user's fovea, while relatively more light at other parts of the retina is scattered light. The amount of scattered light at the fovea can be affected by the size of clear apertures 120a and 120b, respectively, but also by the properties of the dots, particularly those closest to the clear apertures. For example, in some embodiments, dots closest to the clear aperture can be designed to scatter less efficiently than dots farther away. Alternatively or additionally, in some embodiments, dots closest to the clear aperture can be designed to have a smaller angle of forward scatter than dots further away.

[0082] In certain embodiments, the dots can be designed to deliver reduced narrow-angle scatter and increased wide-angle scatter to create a uniform light distribution / low-contrast signal on the retina while maintaining acuity through the geometry of the scattering center. For example, the dots can be designed to generate significant wide-angle forward scatter (e.g., such as greater than 10%, 20% or more, 30% or more, 40% or more, 50% or more, deflected over 2.5 degrees). Narrow-angle forward scatter (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).

[0083] In general, the performance of a dot pattern can be evaluated using a variety of different metrics to optimize the dot pattern for use in myopia-reducing eyewear. For example, the dot pattern can be empirically optimized based on, for example, physical measurements of lenses with 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). A conventional haze meter can be used, such as a BYK-Gardner haze meter (such as a Haze-Gard Plus instrument), which measures the total amount of light transmitted through the lens, the amount of undisturbed transmitted light (e.g., within 0.5 degrees), the amount of light deflected more than 2.5 degrees, and clarity (within 2.5 degrees). Other devices can also be used to characterize light scattering in order to empirically optimize the scattering pattern. For example, a device that measures light diffusion by measuring light in an annular ring around 2.5 degrees (e.g., a Hornell device) can be used.

[0084] Alternatively or additionally, the dot pattern may be optimized by computer modeling software (eg, Zemax or Code V).

[0085] In some embodiments, the dot pattern can be designed based on optimization of a point spread function, which is a representation of 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 diffuse the illumination of the retina, so that the retina outside the fovea is evenly covered with scattered light to reduce (e.g., minimize) the contrast in that retinal region.

[0086] Alternatively or additionally, the dot pattern can be designed based on optimization of the modulus transfer function, which refers to 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 across a range of spatial frequencies. The design parameters of the dot pattern can be varied to increase or decrease certain spatial frequencies as needed. Typically, the spatial frequencies of visual interest are 18 cycles per degree on the fine side and 1.5 cycles per degree on the coarse side. The dot pattern can be designed to provide an enhanced signal at some subset of the spatial frequencies within this range.

[0087] The aforementioned metrics can be used to evaluate dot patterns based on dot size and / or shape, both of which can vary as desired. For example, dots can be substantially round (e.g., spherical), elongated (e.g., elliptical), or irregularly shaped. Typically, the size of the protrusions (e.g., Figure 1BThe diameter shown) should be large enough to scatter visible light, but small enough not to be discernible by the wearer during normal use. For example, the size of the dot (measured in the xy plane) can be about 0.001 mm or larger (e.g., about 0.005 mm or larger, about 0.01 mm or larger, about 0.015 mm or larger, about 0.02 mm or larger, about 0.025 mm or larger, about 0.03 mm or larger, about 0.035 mm or larger, about 0.04 mm or larger, about 0.045 mm or larger, about 0.05 mm or larger, about 0.055 mm or larger). or greater, about 0.06 mm or greater, about 0.07 mm or greater, about 0.08 mm or greater, about 0.09 mm or greater, 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).

[0088] Note that for smaller dots, such as those with a size comparable to the wavelength of light (e.g., 0.001 mm to approximately 0.05 mm), light scattering can be considered Rayleigh scattering or Mie scattering. For larger protrusions, such as approximately 0.1 mm or larger, light scattering may be due to geometric scattering.

[0089] In general, the size of the dot can be the same or can vary across each lens. For example, the size can increase or decrease depending on the location of the protrusion (e.g., as measured from the clear aperture) and / or depending on the distance from the edge of the lens. In some embodiments, the protrusion size varies monotonically (e.g., monotonically increasing or monotonically decreasing) with increasing distance from the center of the lens. In some cases, the monotonically increasing / decreasing size includes linearly varying the diameter of the protrusion as a function of distance from the center of the lens.

[0090] Figure 1B The points shown in are arranged on a square grid, spaced equally in each direction. This is determined by the D y and D in the x direction x In general, the dots are spaced so that together they provide sufficient contrast reduction at the observer's periphery to reduce myopia. In general, smaller dot spacing will result in greater contrast reduction (assuming adjacent dots do not overlap or merge). In general, D x and D yIn the range of 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, the dot pitch may be 0.55 mm, 0.365 mm, or 0.240 mm.

[0091] Although Figure 1B The points shown in the figure are arranged with equal spacing in the x and y directions, but more generally, the spacing in each direction can be different. In addition, the protrusions can be arranged in a non-square grid. For example, a hexagonal grid can be used. Irregular arrays are also possible, for example using random or semi-random point placement. In the case of a random pattern, the dimensions given will be the average spacing of the points in the x and y directions.

[0092] In general, the amount of dot coverage of the lens can be varied as desired. Here, coverage refers to the proportion of the total lens area, as projected onto the xy plane, that corresponds to the dot. Generally, lower dot coverage will produce lower scatter than higher dot coverage (assuming the individual dots are discrete, i.e., they do not merge to form larger dots). Dot coverage can vary from 10% or more to approximately 75%. For example, dot coverage can be 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, 40% or more, 45% or more, such as 50% or 55%. Dot coverage can be selected based on user comfort, for example, to provide a sufficiently comfortable level of peripheral vision that the wearer will voluntarily wear the glasses for extended periods of time (e.g., all day).

[0093] Despite Figure 1B The midpoint is depicted as having a circular footprint, but, more generally, the dots can have other shapes. For example, such as in the case of an elliptical dot, the dot can be elongated in one direction (e.g., in the x-direction or the y-direction). In some embodiments, the shape of the dot is random.

[0094] It can be said that light from the scene incident on the lens in the reduced-contrast regions 130a and 130b between the dots contributes to forming an image of the scene on the user's retina, while light from the scene incident on the dots does not. Furthermore, light incident on the dots is still transmitted to the retina, thereby having the effect of reducing image contrast without substantially reducing light intensity at the retina. Therefore, it can be said that the amount of contrast reduction in the user's peripheral vision is related to (e.g., approximately proportional to) the proportion of the surface area of ​​the reduced-contrast regions covered by the dots. Typically, the dots 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, or 60% or less) of the area of ​​the reduced-contrast regions 130a and 130b (as measured in the xy plane).

[0095] Generally, the dot pattern reduces the contrast of object images in the wearer's peripheral vision without significantly reducing the visual acuity of the observer in this area. Here, peripheral vision refers to the field of view outside the clear aperture. Image contrast in these areas can be reduced by 40% or more (e.g., 45% or more, 50% or more, 60% or more, 70% or more, 80% or more) relative to image contrast observed using a given clear aperture. The contrast reduction can be set based on the needs of each individual case. It is expected that a typical contrast reduction will be in the range of approximately 50% to 55%. Contrast reductions below 50% may be useful in very mild cases, while more susceptible subjects may require contrast reductions above 55%. Peripheral acuity can be corrected to 20 / 30 or better (e.g., 20 / 25 or better, 20 / 20 or better) through subjective refraction while still achieving meaningful contrast reduction.

[0096] Contrast here refers to the difference in brightness between two objects in the same field of view. Therefore, a decrease in contrast refers to a change in this difference.

[0097] Contrast and contrast reduction can be measured in a variety of ways. In some embodiments, contrast can be measured based on the difference in brightness between different parts of a standard pattern (such as a checkerboard of black and white squares) obtained through the lens's clear aperture and dot pattern under controlled conditions.

[0098] Alternatively or additionally, contrast reduction can be determined based on the lens's optical transfer function (OTF) (see, for example, http: / / www.montana.edu / jshaw / documents / 18%20EELE582_S15_OTFMTF.pdf). The OTF specifies the contrast of the transmission for a stimulus in which light and dark areas are sinusoidally modulated at different "spatial frequencies." These stimuli appear as alternating light and dark bars, with the spacing between the bars varying within a certain range. For all optical systems, the contrast transmission is lowest for the sinusoidally varying stimulus with the highest spatial frequency. The relationship describing the transmission contrast for all spatial frequencies is the OTF. The OTF can be obtained by Fourier transforming the point spread function. This is achieved by imaging a point source of light through the lens onto a detector array and determining how the light from the point is distributed across the detectors.

[0099] If conflicting measurements arise, the OTF technique is preferred. In some embodiments, contrast can be estimated based on the ratio of the area of ​​the lens covered by the dots to the area of ​​the clear aperture. This approximation assumes that all light hitting the dots is evenly dispersed across the entire retinal area, reducing the amount of light available in brighter areas of the image and adding light to darker areas. Therefore, contrast reduction can be calculated based on transmission measurements taken through the lens's clear aperture and the dot pattern.

[0100] Typically, ophthalmic lenses 110a and 110b can be clear or tinted. That is, the lenses can be optically clear, appear transparent, and / or colorless for all visible wavelengths, or they can include spectral filters that 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 overstimulation of the L cones in the human eye (particularly in children) can lead to suboptimal eye elongation and myopia. Therefore, using ophthalmic lenses that spectrally filter red light can further reduce myopia in the wearer.

[0101] Spectral filtering can be provided by applying a film to the surface of the lens. The film can be applied by physically depositing a material onto the lens surface, coating a layer of material onto the surface, or laminating a preformed film onto 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 provided by including the filter material in the lens material itself and / or in the material used to form the protrusions.

[0102] refer to Figure 2The effects of spectral filtering and contrast reduction from a dot pattern are illustrated by viewing black text on a white background using glasses 210. The white background of the text takes on a greenish appearance due to the glasses' filtering of red wavelengths. Image contrast is unaffected at clear apertures 220a and 220b, but is reduced elsewhere in the observer's visual frame.

[0103] As described above, in general, the dots can be provided as protrusions and / or depressions on one or both surfaces of each lens and / or as scattering inclusions in the lens material itself. In some embodiments, the dots can be formed by an array of protrusions on a surface (e.g., the back surface or the front surface) of each of the lenses 110a and 110b.

[0104] The protrusions can be formed from an optically clear material with a similar refractive index to 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 with a refractive index similar to PC, such as a light-activated polyurethane or epoxy-based plastic. In addition to PC, the lens itself can also be made from allyl diglycol carbonate plastic, urethane-based monomers, or other impact-resistant monomers. Alternatively, the lens can be made from one of the denser, higher-index plastics with a refractive index greater than 1.60. In some embodiments, the lens is made from an optically clear material with a lower refractive index (e.g., CR39 is 1.50 and Trivex is 1.53).

[0105] Surface dot patterns can also be formed by creating recesses on one or both surfaces of the lens. Figure 3A , lens 300 includes a dot pattern formed by recesses 304 formed on the surface of lens body 302. In this example, a meniscus lens with negative refractive power is depicted. More generally, positive refractive power lenses or lenses with no refractive power may also be used. Recesses 304 may have similar dimensions and / or spacing as the protrusions described above. Recesses 304 may 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 embodiments, the recesses are formed when the lens is molded. In some cases, the recesses may each correspond to an area of ​​the lens surface where sufficient material has been removed to roughen the surface so that the lens surface scatters rather than refracts incident light.

[0106] Lens 300 also includes an optical coating 306 on a surface of lens body 302 opposite recess 304. Optical coating 306 may perform one or more functions, such as anti-reflection, spectral filtering (eg, UV filtering), and / or a protective hard coating.

[0107] In some embodiments, contrast reduction is produced by other diffusing structures, such as a rough surface. A holographic diffuser or a frosted glass diffuser can be used. In some embodiments, the diffuser can be provided by a film laminated onto the lens surface.

[0108] refer to Figure 3B , shows a cross-sectional view of another lens 310. The lens includes a lens body 312 that includes embedded scattering centers 314. The lens 310 also includes an optical coating 316 on one of the surfaces of the lens body. Optical coatings on both surfaces are also possible. The scattering centers are typically formed from a material that has a refractive index that does not match the bulk lens material. For example, when molding the lens, transparent beads of appropriate size can be dispersed in the lens material, where the refractive indices of the bead material and the bulk lens material are different. The clear aperture is formed solely by the bulk lens material.

[0109] In some embodiments, embedded scattering centers 314 can be formed using a process that selectively induces a refractive index change in the bulk lens material. For example, exposure to a laser beam can induce a localized change in the refractive index of the bulk lens material, for example, through photochemical and / or photothermal interactions. An exemplary laser exposure method that can be used to locate the dot pattern is described in detail below.

[0110] Typically, the refractive index mismatch between the lens material and the dot material affects the amount of light scattered at each protrusion, as calculated using a point spread function (PSF). Generally, the greater the refractive index mismatch between the materials, the more the incident light will be scattered. Therefore, the refractive index mismatch can be used as a design parameter to optimize the scattering properties of the dot.

[0111] In some embodiments, the protrusion material is selected to have a refractive index (e.g., as measured at one or more wavelengths in the visible range) 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.

[0112] In some embodiments, a larger refractive index mismatch (e.g., greater than 0.1) is possible. For example, the protrusion material can be selected to have a refractive index that differs from the refractive index of the lens material by 0.15 or more (e.g., 0.2 or more, 0.25 or more, 0.3 or more, 0.35 or more, such as up to about 0.4).

[0113] In general, the refractive index of each point can be the same or different. For example, where each point is formed from the same material, each point can have the same refractive index. Alternatively, in some embodiments, the refractive index can vary between points or between different groups of points. For example, in certain embodiments, the refractive index mismatch between a point and the lens block material can increase with increasing radial distance from the lens axis, thereby increasing the amount of light scattered from each point with increasing radial distance from the lens axis.

[0114] 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 only certain wavelengths of light (e.g., to absorb short-wavelength components or long-wavelength components). It is believed that light-absorbing materials can help reduce glare and / or provide another design parameter for the point spread function used to shape the dots. In some embodiments, exposure to radiation can change the lens material from transparent to absorptive at specific wavelengths. For example, exposure to radiation can burn the lens material to form light-absorbing centers in or on the surface of the lens material.

[0115] As previously mentioned, the size, spacing, and arrangement of the dot pattern can generally vary. In some embodiments, the dot pattern can be characterized by, for example, a gradient in dot size and / or spacing. The dot pattern can also be characterized by a gradient in the scattering efficiency of the dots (e.g., due to a gradient in the refractive index mismatch and / or shape of each dot). A gradient dot pattern can reduce the conspicuousness of the pattern. For example, a gradual transition from a clear portion to a scattering portion of a lens may be less noticeable than a sharp transition.

[0116] In some embodiments, the lens may feature different regions where the dot pattern varies from region to region. Figure 4A and Figure 4B The lens 400 includes a clear aperture 410, a transition zone 420, and a scattering zone 430. The clear aperture 410 has a radius R410, and the transition zone 420 is an annular zone surrounding the clear aperture, and the annular zone has an inner diameter R 410 and outer diameter R 420 The rest of the lens area forms a scattering zone 430 .

[0117] Transition zone 420 features a dot pattern that scatters incident light less than the dot pattern in scattering zone 430, thereby providing a transition in the scattering properties of the lens from the clear aperture to the scattering zone. This transition can be advantageous because it reduces scatter entering the fovea compared to the scattering that would be provided if the scattering zone extended into the clear aperture. Another advantage is that the transition zone can reduce the visibility of the dot pattern to the user, thereby providing a more comfortable wearing experience. This is particularly important for children, as the likelihood of a child wearing eyeglasses featuring such lenses on a regular basis for extended periods of time depends on the child's comfort level.

[0118] In general, the dot pattern in the transition region 420 can vary. In some embodiments, the transition region is characterized by a uniform dot pattern, where the dots have the same shape and size and are evenly spaced. Alternatively, in some embodiments, the dot pattern in the transition region can be characterized by varying dot density, spacing, and / or size. For example, the dot pattern can be selected to provide the weakest scattering closest to the clear aperture and at a point in the transition region from R 410 to R 420 For example, in some embodiments, the point density increases monotonically with increasing radial distance from R 410 to R 420 Monotonically (e.g. linearly) increases. For example, as the radial distance from the lens axis increases from R 410 Increase to R 420 , the dot diameter may increase linearly from a first value (eg, 0.05 mm) to a second value (eg, 0.17 mm). Alternatively or in addition, the dot spacing may be increased from R 410 to R 420 Monotonically (e.g., linearly) decreasing.

[0119] Usually, R 410 In the range of about 1 mm to about 3 mm (e.g., 1.0 mm to 1.1 mm, 1.1 mm to 1.2 mm, 1.2 mm to 1.3 mm, 1.3 mm to 1.4 mm, 1.4 mm to 1.5 mm, 1.5 mm to 1.6 mm, 1.6 mm to 1.7 mm, 1.7 mm to 1.8 mm, 1.8 mm to 1.9 mm, 1.9 mm to 2.0 mm, 2.0 mm to 2.1 mm, 2.1 mm to 2.2 mm, 2.2 mm to 2.3 mm, 2.3 mm to 2.4 mm, 2.4 mm to 2.5 mm, 2.5 mm to 2.6 mm, 2.6 mm to 2.7 mm, 2.7 mm to 2.8 mm, 2.8 mm to 2.9 mm, 2.9 mm to 3.0 mm).

[0120] R 420It can 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).

[0121] In some embodiments, the dot pattern includes randomly displaced dots relative to a regular array. Introducing random displacements can reduce optical effects associated with regularly spaced scattering centers (such as starburst glare). See, for example, https: / / www.slrlounge.com / diffraction-aperture-and-starburst-effects / , which illustrates the starburst effect associated with photography. Thus, including random displacements in the dot pattern can provide a more comfortable experience for the user compared to a similar dot pattern in which the scattering centers are evenly spaced. Alternatively or additionally, randomization of the dot pattern can reduce optical effects (e.g., diffraction or interference effects) manifesting in the reflected light, thereby reducing the perceptibility of the dot pattern to the observer.

[0122] exist Figure 4C The random displacement is shown in FIG. 4 , which shows points 401 a - 401 e positioned relative to the array lattice, where adjacent lattice nodes are spaced D from each other in the x-direction. x , spaced D apart from each other in the y direction y As shown in the figure, D x = D y , however, more generally, the vertical and horizontal lattice spacings can be different.

[0123] For each point, δx = A x ∙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 and y directions respectively, which can be the same or different. RN[0,1] is a random number between 0 and 1.

[0124] The dot size can also vary randomly, which can reduce optical effects, such as glare, associated with arrays of uniformly sized dots. Figure 4C As shown, the radial size of each point can be different from the nominal point radius r0. As shown, point 401d has a nominal point radius r0, while points 401b and 401e each have a radius r that is greater than r0. b and r e And r b ≠r e The point radius can be calculated according to the formula r i = r0 + Δr to set, where Δr = A r ∙r0∙RN[0,1], where i represents the i-th point, A r is the point radius jitter amplitude, which is set to a value between 0 and 1.

[0125] More generally, while the examples above involve the dot radius of nominally circular dots, dithering can be applied to other dot size parameters, depending on the application. For example, dithering can be applied to dot volume or other dot dimensions (e.g., x-dimension, y-dimension).

[0126] In some embodiments, the dot pattern may include both random jitter in dot position and random jitter in dot size.

[0127] exist Figures 5A-5F An exemplary dot pattern featuring a transition zone is shown in . Figure 5A 、 5C The patterns in 5A and 5E are characterized by dots evenly spaced in the scattering region. Figure 5B 、 5D The patterns of 5F and 5F are characterized by dots randomly displaced from uniform spacing. The units of the horizontal and vertical axes are both mm. Figures 5A-5F Each of includes an inset showing a magnified view of the corresponding dot pattern. The following table provides parameters that characterize the dot patterns.

[0128]

[0129] In some embodiments, the dot pattern can be characterized by, for example, a gradient in dot size and / or spacing. The dot pattern can also be characterized by a gradient in the scattering efficiency of the dots (e.g., due to a gradient in the refractive index mismatch and / or shape of each dot). A gradient dot pattern can reduce the obtrusiveness of the pattern. For example, a gradual transition from a clear portion to a scattering portion of a lens may be less noticeable than a sharp transition.

[0130] refer to Figure 6A and 6B , showing an exemplary gradient dot pattern.

[0131] Specifically, Figure 6AA gradient dot pattern 600 is shown, with varying spacing between adjacent dots. A clear aperture 610 transitions into a low-density region 620. In region 620, the distance between adjacent dots is relatively large, resulting in a low density of dots in region 620. Low-density region 620 then transitions into a high-density region 530, where the spacing between adjacent dots is small, resulting in a high density of dots. High-density region 630 then transitions into a low-density region 640, where the spacing between adjacent dots increases again. As a result, due to the gradual transition from clear aperture 610 to the outer edge of the lens, the gradient dot pattern may be less noticeable than a transition to a higher-density, uniform dot pattern.

[0132] Point density can be controlled not only by the spacing between adjacent points, but also by the point size. Figure 6B For example, dot pattern 650 is characterized by smaller sizes of dots near clear aperture 660 compared to dots near edge 680 of the dot pattern.

[0133] In another example, a lens may have a graduated dot pattern having both varying dot size and varying dot-to-dot distance.

[0134] The shape and / or composition of the dots may also vary radially, thereby producing a gradient pattern. For example, for block-shaped scattering centers, a gradient pattern may be provided by forming scattering centers with a lower refractive index mismatch with the lens block material closer to the edge of the dot pattern than with scattering centers at the center of the dot pattern.

[0135] In some embodiments, information can be encoded into the dot pattern. For example, variations in the spacing, size, and / or shape of the dot pattern can be introduced based on a key, allowing the information to be subsequently read by someone with the key. In some cases, information about the wearer, such as their identity and information about their vision, can be encoded into the dot pattern.

[0136] In some embodiments, the dots may be dots of varying sizes. Figure 7A , lens 700 includes a clear aperture 702 and a dot pattern including dots of different sizes: small dots 704 and large dots 706. In one embodiment, small dots 704 are small relative to large dots 706, and thus, large dots 706 are large relative to small dots 704.

[0137] In certain embodiments, small dots 704 and large dots 706 may correspond to binary components. For example, small dot 704 corresponds to 0 and large dot 706 corresponds to 1, because the intensity of the reflected light from small dot 704 and large dot 706 will differ and can be interpreted as a binary code. When read as a string of characters, small dots 704 and large dots 706 form a binary code sequence that encodes information, including but not limited to the wearer's identity or visual information. For example, the encoded information may include lens prescription information.

[0138] In some embodiments, in addition to small dot size 704 and large dot size 706, other dot sizes may be present, e.g., the dot size of the dot pattern is not limited to two sizes. For example, when the sensor detects reflected light from the encoded dot pattern on the lens 700, various dot sizes corresponding to different outputs may be used. The sensor may be configured to detect three or more different intensities of reflected light (e.g., the intensities of reflected light from three or more different dot sizes of the dot pattern on the lens 700).

[0139] In some embodiments, the points may be annular rings of varying thickness. Figure 7B , lens 720 includes a clear aperture 722 and a dot pattern including a “ring” 724 (eg, a dot having a circular ring and a transparent center) and dot 726 .

[0140] In certain embodiments, the rings 724 and dots 726 may correspond to binary components. For example, the rings 724 correspond to 0, while the dots 726 correspond to 1. When read as a string, the rings 724 and dots 726 form a binary code sequence that encodes information, including but not limited to the wearer's identity or visual information. For example, the encoded information may include lens prescription information.

[0141] In one embodiment, the size, shape, and / or thickness of the ring 724 varies, thereby varying the intensity of the reflected light. A sensor can be configured to detect the varying intensity of the reflected light and convert it into an analog signal that is transmitted to a decoder. For example, certain shapes, sizes, and thicknesses of the ring 724 can correspond to predetermined encoded information. For example, a ring with a certain thickness can correspond to a predetermined lens prescription strength, and as the thickness of the ring increases, the lens prescription strength also increases.

[0142] In some embodiments, the dots may be shaped into symbols, such as alphanumeric symbols or logos. Figure 7C , lens 740 includes a clear aperture 742 and a dot pattern of symbols 744.

[0143] In certain embodiments, symbol 744 may be a logo, a common symbol, various symbols, a simple shape, a complex shape, alphanumeric characters, letters, and / or words. For example, symbol 744 may be a number indicating the strength of the prescription. In another example, symbol 744 may be a manufacturer's logo indicating where to order replacement lenses. In another example, symbol 744 may be a shape indicating a diagnosis for a particular wearer (e.g., an ellipse with varying meridian lengths and heights corresponding to the wearer's degree of myopia and astigmatism).

[0144] Typically, the variations in dot spacing, size, and / or shape are invisible to unaided human vision, and magnifying optics and / or machine reading systems are used to read the encoded information. In certain embodiments, a microscope reader is used to read the encoded information. For example, a microscope or similar magnifying optical system is used to enable an optometrist or lens technician to read the encoded information from a lens.

[0145] In certain embodiments, a machine reading system is used to read the encoded information. Figure 8 , the machine reading system 800 includes a lens 801 having a clear aperture 802 surrounded by a dot pattern 803, an illuminator 812, light 814, reflected light 816, a sensor 818, a database 820, a decoder circuit 822 and a controller 824.

[0146] In some embodiments, the system 800 includes a light emitter 812. For example, the light emitter 812 shines light 814, such as an LED or a laser, onto the dot pattern 803. The dot pattern 803 is, for example, Figures 7A-7C The coding pattern shown in .

[0147] Light 814 is reflected (or not reflected) from dot pattern 803 in the form of reflected light 816. The intensity of reflected light 816 varies (e.g., ranging from no reflection to 100% reflection), as certain dots or the absence of dots may result in total or no reflection of light 814. Reflected light 816 may also be a partial reflection of light 814. Similarly, in some embodiments, transmitted light or a combination of transmitted and reflected light may be used to read out encoded information.

[0148] In certain embodiments, system 800 includes a sensor 818. For example, sensor 818 is a light detector, such as a photocell. Various embodiments of sensor 818 may include, but are not limited to, a laser scanner and a camera-based reader. 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.

[0149] In some embodiments, the signal generated by the sensor 818 is sent to the database 820. For example, the database 820 can cross-reference the symbol (i.e., from Figure 7C The sensor 802 may also perform an image recognition search for the symbol to decode the signal. Database 820 may contain a library of symbols, images, text, and codes. For example, if dot pattern 803 includes a complex shape such as a logo or symbol, the sensor may send a signal related to the complex shape to database 820 for cross-reference.

[0150] In one embodiment, decoder circuit 822 decodes the signal from sensor 818 and converts it into a digital signal. A digital signal is a digital representation of the signal from sensor 818, such as a binary code where a 0 represents an off pulse and a 1 represents an on pulse.

[0151] The decoder circuit 822 sends the digital signal to the controller 824. The digital signal can be read by the controller 824. For example, the decoder circuit 822 can send a binary code that the controller 824 converts into text so that the information encoded on the dot pattern 803 can be read.

[0152] While the above embodiments feature an example in which the contrast-reducing region is annular (e.g., concentric circles surrounding the clear aperture), other shapes are more generally possible. For example, elongated (e.g., elliptical) shapes are possible. Generally, the contrast-reducing region may cover the entire lens outside the clear aperture, or only a portion, leaving the lens transparent at the periphery.

[0153] Generally, dots can be formed from a lens in a variety of ways. For example, dots can be formed using inkjet technology, such as those disclosed in PCT / US2017 / 044635, entitled "Ophthalmic Lens for Treating Myopia," filed on July 31, 2017, the entire contents of which are incorporated herein by reference.

[0154] 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, creating the dots. Generally, as discussed in the examples below, a laser can be used to form dots on the surface of a lens or in the bulk material of the lens. For example, exposing the surface of a lens to a laser beam having sufficient energy can create dots by leaving small depressions and / or roughened spots on the surface. By selectively exposing areas of the lens surface to the laser radiation, a pattern of dots can be formed on the surface. For example, when the laser beam is pulsed, the laser beam can move relative to the surface. The relative motion between the beam and the lens surface can be caused by moving the beam while holding the surface fixed, moving the surface while holding the beam fixed, or moving both the beam and the surface.

[0155] Generally, the optical properties of the spots formed on a lens surface using a laser can be influenced in a variety of ways. For example, the energy density of the laser beam pulse will generally affect the physical and / or chemical interaction of the laser with the lens material. For example, at certain pulse energies, the lens material may melt where it is exposed, forming the spot. At some pulse energies, the spot may be formed by foaming the lens material. This can occur at higher energies than melting the lens. At some pulse energies, the interaction between the laser and the lens material may cause discoloration of the lens material (e.g., through charring). In other cases, the lens material may be removed from the lens surface by ablation.

[0156] Other laser parameters may also affect the properties of the dots formed using the laser. These parameters include laser wavelength, exposure time (e.g., exposure time per dot location), and number of passes (e.g., exposing an area multiple times with exposures to other areas between passes), each of which can be selected to achieve the desired surface modification. Furthermore, the interaction between the laser and the lens material will depend on the lens material itself. For example, dots in a lens material with a lower glass transition temperature can be formed using lower pulse energy or fewer pulses than dots in a lens material with a relatively higher glass transition temperature.

[0157] In some embodiments, the laser and its operating parameters are selected to provide a spot with a specific range of forward scattering angles (e.g., between 3 and 30 degrees). Specifically, the laser parameters can be selected to achieve a surface modification that results in a forward scattering angle of 15.5 to 19.5 degrees. In some cases, the laser parameters are selected to achieve a scattering efficiency (e.g., haze) of 10-50%. Specifically, the laser parameters can be selected to achieve a scattering efficiency of 15% to 19% and 38% to 42%.

[0158] The resolution of the laser beam at the lens surface can be smaller than the desired spot size. For example, the beam resolution (e.g., as determined based on the FWHM of the intensity distribution) can 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 spot size. In some embodiments, the beam can form features having a size of 100 μm or less (e.g., 50 μm or less, 20 μm or less, 10 μm or less, 5 μm or less).

[0159] refer to Figure 9 Laser system 900 for forming a spot on the surface of a lens includes a laser 920, a beam chopper 930, focusing optics 940, a mirror 950, and a stage 970. Laser 920 directs a laser beam toward mirror 950, which deflects the beam toward lens 901, which is positioned relative to mirror 950 by stage 970. An actuator 960 (e.g., a piezoelectric actuator) is attached to mirror 950. The stage includes a lens mounting surface 980 that supports lens 901. Laser system 900 also includes a controller (e.g., a computer controller) that communicates with laser 920, beam chopper 930, and actuator 960.

[0160] A beam chopper 930 and focusing optics 940 are positioned in the beam path. Chopper 930 periodically blocks the beam, exposing lens 901 to discrete laser pulses. Focusing optics 940, which typically include one or more optical dynamic elements (e.g., one or more lenses), focus the beam to a sufficiently small spot on the surface of lens 901 so that the area ablated by the beam on the lens surface corresponds to the desired spot size. Actuator 960 changes the orientation of mirror 950 relative to the beam to scan the pulsed beam to different target points on the lens surface. Controller 910 coordinates the operation of laser 920, chopper 930, and actuator 960 so that the laser system forms a predetermined spot pattern on the lens.

[0161] In some embodiments, the stage 970 further includes an actuator. The stage actuator can be a multi-axis actuator, for example, to move the lens in two lateral dimensions orthogonal to the direction of beam propagation. Alternatively or additionally, the actuator can move the stage along the direction of the beam. Moving the stage along the direction of the beam can be used to maintain the exposed portion of the lens surface at the focal position of the beam, regardless of the curvature of the lens surface, thereby maintaining a substantially constant spot size across the entire lens surface. The stage actuator can also be controlled by the controller 910, which coordinates the stage motion with other elements of the system. In some embodiments, a stage actuator is used in place of a mirror actuator.

[0162] In general, laser 920 can be any type of laser capable of generating light with sufficient energy to ablate the 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. Commercially available laser systems, such as, for example, CO2 laser systems manufactured by Universal Laser Systems, Inc. (Scottsdale, Arizona) (e.g., the 60W VLS 4.60 system), can be used. In some embodiments, a femtosecond laser can be used. For example, a commercial femtosecond laser system, such as a femtosecond laser system manufactured by Trumpf (Santa Clara, California) (e.g., the TruMicro 2030 laser device available as the TruLaser Station 5005), can be used to form a dot pattern of the desired shape and size. The burst mode of such laser devices can achieve much higher burst energies than the maximum energy of a single pulse, resulting in higher ablation rates. This exemplary laser system can provide a pulse duration of less than 400 femtoseconds and a maximum pulse energy of 50 μJ.

[0163] The pulse duration and pulse energy are typically selected to provide a desired dot size. For example, in some embodiments, the laser 920 forms a predetermined dot pattern on the lens 901 by melting the surface of the lens 901 (e.g., laser etching). For example, the laser 920 heats and melts a portion of the surface of the lens 901 to form the dot because the laser etching expands the melted material of the lens 901, forming a concave dimple and a raised well around it, thereby forming the dot.

[0164] In certain embodiments, laser 920 uses laser bubbling to form a predetermined dot pattern on lens 901. For example, when the laser interacts with the lens material, the material softens or melts, and bubbles form within the softened / molten material. When the material cools and returns to its room temperature state, these bubbles become trapped. The trapped bubbles effectively scatter light, thereby providing the dots.

[0165] In an embodiment, the laser 920 forms a predetermined dot pattern on the lens 901 using a laser marker. For example, the laser marker forms the predetermined dot pattern on the lens 901 by causing a color change on the lens 901, for example, due to a chemical or physical change in the portion of the lens 901 that forms the predetermined dot pattern. In another embodiment, the laser 920 forms the predetermined dot pattern on the lens 901 by carbonizing the lens 901 using the laser marker to form the predetermined dot pattern on the lens 901.

[0166] In some embodiments, laser 920 uses ablation to form a predetermined dot pattern on lens 901. For example, laser 920 is used to ablate (e.g., remove material) lens 901 by locally evaporating or sublimating the material of lens 901 to form the predetermined dot pattern. After ablation, pits are formed on lens 901.

[0167] In some embodiments, to reduce the conspicuity of the dot pattern (e.g., to reduce backscattering and reflections at the scattering centers due to the ablated pits), the surface of the ablated pits on lens 901 is modified to reduce surface roughness. Reducing surface roughness can reduce the effects of small-angle light scattering (e.g., where the scattering angle is less than 3 degrees). For example, the surface of the ablated pits on lens 901 can be modified by a second pass to melt the roughened surface of the ablated pits (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 embodiments, continuing to reduce the conspicuity of the dot pattern involves defocusing the laser 920 in multiple iterations. For example, defocusing the laser 920 can occur over several passes (e.g., every second, third, fourth, etc. pass) at increasing defocus (e.g., increasing the beam width with each pass) to affect the taper of the pits (e.g., feathering or smoothing the pit edges). In some embodiments, reducing the conspicuity of the dot pattern includes performing multiple overlapping ablations to form an ablation pit having multiple overlapping ablation pits (eg, two or more overlapping concentric circles).

[0168] In some embodiments, reducing the conspicuity of the dot pattern includes applying an antireflective coating to the back surface of lens 920. In some embodiments, a reflective coating is applied to the front surface of the lens. This is particularly beneficial if laser ablation is performed on the back surface of lens 901. Typically, laser 920 has a greater effect on the coating than on the material of lens 901, thereby affecting the taper of the dimples (e.g., feathering or smoothing the dimple edges).

[0169] In some embodiments, focusing optics with a small depth of focus can be used in conjunction with the curvature of the lens surface to provide a variable spot size across the lens surface. Figure 10, and similar to system 900, laser system 1000 for forming a spot on the surface of lens 1001 includes a laser 1020, a beam chopper 1030 (or other modulator for generating laser pulses), focusing optics 1040, a mirror 1050, and a stage 1080. Laser 1020 directs a laser beam 1025 toward mirror 1050, which deflects beam 1025 toward lens 1001, which 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.

[0170] A beam chopper 1030 and focusing optics 1040 are positioned in the beam path. Chopper 1030 periodically blocks beam 1025, exposing lens 1001 to discrete laser pulses. Focusing optics 1040 focus beam 1025 to a sufficiently small spot 1045 on or near the surface of lens 1001 so that the area ablated by beam 1025 on the lens surface corresponds to the desired spot size. Actuator 1060 changes the orientation of mirror 1050 relative to beam 1025 to scan 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 predetermined spot pattern on lens 1001.

[0171] like Figure 10 As indicated by the arrow in the figure, the motion stage 1080 moves the lens 1001 laterally parallel to the focal plane 1035 of the laser beam 1025. Due to the curvature of the lens surface, the lens surface will not always coincide with the focal plane 1035 at the laser beam's focal spot 1045. This means that the intensity of the laser radiation at the lens surface will vary depending on the lateral position of the lens relative to the laser spot 1045. In general, the amount of etching on the lens surface will depend on the intensity of the laser radiation it receives. Therefore, locations on the lens surface exposed to an out-of-focus beam will experience less etching intensity than locations where the lens surface coincides with the focal plane 1035. Assuming constant laser pulse duration and lateral translation speed, the etching rate will be highest at locations where the lens surface coincides with the focal plane 1035, and will decrease as the lens is translated further from this location. Thus, a gradient pattern can be achieved simply based on the curvature of the lens surface.

[0172] Of course, other exposure parameters (e.g., pulse time, pulse energy, spot composition, such as location of spots formed by multiple overlapping or nearby ablation centers, bubbled or melted areas) can be used with or separately from lens curvature to obtain the desired gradient spot pattern.

[0173] Laser systems can also be used to create scattering centers in the bulk material of a 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 through one or more different mechanisms, such as photochemical changes, photothermal changes (e.g., light causes heating, which changes the properties of the material), and / or some other mechanism. In general, the greater the intensity, the greater the change in the optical material will be. In many cases, this change is not necessarily a linear relationship. For example, there may be some threshold intensity below which little, if any, change occurs in the bulk material. At some threshold intensity, changes begin to occur. For example, referring to Figure 11A , a graph showing this nonlinear relationship between the refractive index change of the lens material and the laser intensity.

[0174] Laser radiation with a relatively low intensity I0 produces only a small change in the refractive index ΔR0; however, when the laser intensity reaches 2I0, a significant change in the refractive index ΔR0 occurs.

[0175] This nonlinear behavior of refractive index variation can be used to locate scattering centers embedded in the lens material. For example, the lens can be exposed to two or more laser beams, each with a beam intensity below the threshold intensity for inducing a significant refractive index change. While each laser beam is too weak to produce a noticeable refractive index change, the area where the laser beams overlap (e.g., all laser beams can be focused on the same point) will experience sufficient refractive index change to correspond to the creation of scattering centers. Alternatively, if the beam focus is located within the bulk material, optics with a narrow focal zone can be used.

[0176] For example, reference Figure 11B , shows a laser system 1105 that uses two overlapping beams to create embedded scattering centers 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 generates a scattering center in a manner similar to Figure 10 The focusing optics and mirrors are configured to focus the beams 1185A and 1185B to a common region 1190 within the lens 1101 where the intensity of the overlapping beams is sufficient to effect a change in the lens material sufficient to form scattering centers. Outside the overlap region, the intensity drops rapidly to a value below any threshold for significant refractive index change.

[0177] More than two lasers may be used. Alternatively or additionally, the beams from a single laser may be split and directed separately to the lens so that they overlap at the target area, thereby creating scattering centers.

[0178] Other arrangements are also possible. For example, multiple laser beams can be fired from the same surface instead of from Figure 11B The opposing surfaces shown enter the lens.

[0179] While the foregoing description relates to ophthalmic lenses for use in eyeglasses, 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 adjusted so that they subtend a comparable solid angle in the user's field of view as the dot pattern described for the eyeglass lenses above.

[0180] Example

[0181] Dots were formed on the Trivex lenses using a Trumpf Trumark 5000 marking laser station equipped with a nanosecond UV laser with a pulse repetition rate of 20 kHz. The laser station operated at a scanning speed of 1,000 mm / s and 100% output power. The dots were approximately 170 microns in diameter and produced a haze of 15% to 42%, 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, composed of individual laser marks with a diameter of approximately 0.04 mm, resulting in a total dot diameter of 0.17 mm. The spacing between adjacent dots was either 0.24 mm or 0.365 mm.

[0182] Other embodiments

[0183] Various embodiments are described. Other embodiments are within the following claims.

Claims

1. A method comprising: focusing the laser beam to a focal point; exposing an ophthalmic lens to focused laser radiation to form optical scattering features in a pattern on a curved surface of the ophthalmic lens, Wherein exposing the ophthalmic lens comprises causing relative motion between the laser beam and the lens such that different locations of the lens surface intersect the laser beam at different locations relative to the focal point.

2. The method according to claim 1, wherein The optical scattering characteristics formed by the laser beam vary depending on the position of the lens surface relative to the focal point.

3. The method according to claim 2, wherein: The degree of scattering due to the optical scattering feature decreases as the distance of the lens surface relative to the focal point increases.

4. The method according to any one of claims 1 to 3, wherein: The pattern includes an annular region of optically scattering features surrounding a clear aperture corresponding to a viewing axis of the ophthalmic lens.

5. The method according to claim 4, wherein The optical scattering features include discrete points.

6. The method according to claim 5, wherein: The dots are arranged in an array, each dot is spaced apart by a distance of 1 mm or less, and the maximum dimension of each dot is 0.5 mm or less.

7. The method according to claim 5, wherein: The clear aperture is a dot-free area having a maximum dimension greater than 1 mm.

8. The method according to any one of claims 1 to 7, wherein The laser is an infrared laser.

9. The method according to any one of claims 1 to 8, wherein The laser is a CO2 laser.

10. The method according to any one of claims 1 to 9, wherein The ophthalmic lens is exposed to pulsed laser radiation.

11. The method according to any one of claims 1 to 10, wherein The laser has sufficient energy to remove lens material from the surface of the lens.

12. The method according to any one of claims 1 to 11, wherein The laser has a power in the range of 0.5W to 60W.

13. The method according to any one of claims 1 to 12, wherein During the exposure, the laser radiation is focused to a spot size of about 0.1 mm or less.

14. The method according to claim 13, wherein During the exposure, the laser radiation is focused to a spot size of about 0.05 mm or less.

15. The method according to claim 13, wherein During the exposure, the laser radiation is focused to a spot size of about 0.025 mm or less.

16. The method according to any one of claims 1 to 15, wherein The ophthalmic lens is exposed such that each location at the lens surface that is exposed experiences a corresponding discrete exposure of the same duration and the same energy.

17. The method according to any one of claims 1 to 16, wherein: The exposed surface is a convex surface.

18. The method according to any one of claims 1 to 16, wherein The exposed surface is a concave surface.

19. A method of forming scattering centers in an ophthalmic lens, comprising: exposing a region of the ophthalmic lens to laser radiation having a wavelength and power sufficient to cause bubbling of a material forming the ophthalmic lens, Therein, gas bubbles resulting from the foaming form scattering centers in the ophthalmic lens.

20. A method comprising: exposing an ophthalmic lens formed from a lens material to two or more beams of laser radiation simultaneously such that the 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 optical scattering features in the lens material; and The positions of the overlapping light beams in the lens are varied to form a pattern of optical scattering features in the lens.

21. The method according to claim 20, wherein The laser intensity of a single beam of the two or more beams is insufficient to form optical scattering features in the lens material in less than 10 seconds of exposure to the laser beam.

22. The method according to claim 20 or 21, wherein The laser radiation in the overlapping beams interacts with the lens material to change the refractive index of the lens material.

23. The method according to claim 22, wherein The laser radiation in the overlapping beams changes the refractive index of the lens material by inducing a photochemical change in the lens material.

24. The method according to claim 22, wherein The laser radiation in the overlapping beams changes the refractive index of the lens material by inducing photothermal changes in the lens material.

25. A pair of glasses, including: Eyeglass frames; and A pair of ophthalmic lenses mounted in the frame, each of the lenses including a pattern distributed across each lens, each lens formed using the method of claim 1, claim 19, or claim 20.

26. The glasses according to claim 25, wherein: Each pattern includes a region including optically scattering features surrounding a clear aperture that is devoid of scattering features.

27. The glasses according to claim 25, wherein: The dot pattern reduces the image contrast of an object viewed through the dot pattern by at least 30% compared to the image contrast of an object viewed through the clear aperture.

28. The glasses according to claim 25, wherein: The dot pattern reduces the image contrast of an object viewed through the dot pattern by at least 35% compared to the image contrast of an object viewed through the clear aperture.

29. The glasses according to claim 25, wherein: The dot pattern reduces the image contrast of an object viewed through the dot pattern by at least 40% compared to the image contrast of an object viewed through the clear aperture.

30. The glasses according to claim 25, wherein: The dot pattern reduces the image contrast of an object viewed through the dot pattern by at least 45% compared to the image contrast of an object viewed through the clear aperture.

31. The glasses according to claim 25, wherein: The dot pattern reduces the image contrast of an object viewed through the dot pattern by at least 50% compared to the image contrast of an object viewed through the clear aperture.

32. The glasses according to claim 25, wherein: The dot pattern reduces the image contrast of an object viewed through the dot pattern by at least 55% compared to the image contrast of an object viewed through the clear aperture.

33. The glasses according to claim 25, wherein: The dot pattern reduces the image contrast of an object viewed through the dot pattern by at least 60% compared to the image contrast of an object viewed through the clear aperture.

34. The glasses according to claim 25, wherein: The lens has an optical power that corrects the wearer's on-axis vision to 20 / 20 or better through the clear aperture and corrects the wearer's vision to 20 / 25 or better for at least a portion of the wearer's peripheral vision through the dot pattern.

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