Lens set for use in preventing or slowing development or progression of myopia and related method

Abstract

To provide a set of contact lenses (200) for use in preventing or slowing the development or progression of myopia, and methods of manufacturing and using such lenses.SOLUTION: Each lens (201a, 201b) includes an optic zone (202a, 202b) and a surrounding peripheral zone (204a, 204b) that has a varying thickness profile that is configured to control rotation of the lens (201a, 201b). The optic zone (202a, 202b) comprises a central region (205a, 205b) having a curvature providing a base power. An annular region (203a, 203b) circumferentially surrounds the central region (205a, 205b) and comprises a treatment zone (207a, 207b).SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure (the present invention) relates to a set of contact lenses for use in preventing or slowing the progression or worsening of myopia. The disclosure also relates to methods of making such lenses and methods of using such lenses. [Background technology]

[0002] Myopia (nearsightedness) affects a significant number of people, including children and adults. The myopic eye focuses incoming light from distant objects to a location in front of the retina. As a result, the light converges toward a plane in front of the retina and diverges toward the retina, becoming unfocused upon reaching the retina. Conventional lenses (e.g., spectacle or contact lenses) for correcting myopia reduce the convergence (with contact lenses) or cause divergence (with spectacle lenses) of the incoming light from distant objects before it reaches the eye, causing the focal point to be shifted onto the retina.

[0003] Decades ago, it was suggested that undercorrection, i.e., moving the focus closer to the retina but not completely onto it, could be used to slow or prevent the progression of myopia in children or young people. However, the inevitable result of this approach is a loss of distance vision compared to that obtained with a lens that completely corrects myopia. Furthermore, the effectiveness of undercorrection in controlling myopia during progression is now considered questionable. A more recent approach is to provide lenses that have both areas that provide complete correction of distance vision and areas that are undercorrected or intentionally induce myopic defocus. Lenses may also be provided that increase the scattering of light in certain areas compared to light that passes through the fully corrected areas of the lens. It has been suggested that these approaches can stop or slow the progression or progression of myopia in children or young people while still providing good distance vision.

[0004] In the case of lenses with defocusing areas, the area that provides full correction of distance vision is commonly called the base power area, and the area that provides undercorrection or intentionally causes myopic defocus is commonly called the add area or myopic defocus area (because the power expressed in diopters is slightly more positive (+) or slightly more negative (-) than the power of the distance vision area). The surface of the add area (typically the anterior surface) has a smaller radius of curvature than that of the distance vision area, thus providing a slightly more positive or slightly more negative power to the eye. The add area is designed to focus incoming parallel light rays (i.e., light from far away) in front of the retina (i.e., located near the lens) in the eye, while the distance area is designed to focus light so that it can be imaged at the retina (i.e., located far away from the lens).

[0005] For lenses that increase the scattering of light in certain areas, features that increase scattering may be built into the lens surface or may be built into the material used to form the lens, for example, scattering elements may be baked into the lens.

[0006] One known type of contact lens that reduces the progression of myopia is a bifocal contact lens marketed under the name MISIGHT (CooperVision, Inc.). This bifocal lens differs from bifocal or multifocal contact lenses designed to improve presbyopic vision in that the bifocal lens has certain optical dimensions that allow an accommodative individual to use distance correction (i.e., base power) to see both distant and near objects. The treatment zone of the bifocal lens, which has an add power, also provides a myopically defocused image at both distance and near vision distances.

[0007] Although these lenses have been found to be beneficial in preventing or slowing the progression or progression of myopia, the annular add power area may produce undesirable visual side effects. The light focused by the annular add power area in front of the retina diverges from the focal point, forming a defocused annulus at the retina. Thus, the wearer of these lenses may see a ring or "halo" surrounding the image created on the retina, especially for small shiny objects, such as street lights or car headlights. Also, in theory, instead of using the natural accommodation of the eye (i.e., the eye's natural ability to change focal distance) to focus on nearby objects, the wearer may utilize the additional focal point in front of the retina caused by the annular add power area to focus on nearby objects; in other words, the wearer may accidentally use the lens in the same way that presbyopic corrective lenses are used, which is undesirable for young subjects.

[0008] Other lenses have been developed that can be used in the treatment of myopia, but which are designed to eliminate the halos observed around the focused distant image in the above-mentioned MISIGHT (CooperVision, Inc.) lens and other similar lenses. In these lenses, the annular region is configured to avoid a single on-axis image in front of the retina, thereby preventing such an image from being used to avoid the eye having to address a nearby target. In contrast, a distant point source is imaged by the annular region into a ring-shaped focal line at the near add focal plane, thereby producing a small spot size of light at the far focal plane without a surrounding "halo" effect on the retina. Summary of the Invention [Problem to be solved by the invention]

[0009] It has been recognized that the eye may adapt over time to compensate for myopic defocus and light scattering features built into the lens. This may reduce the effectiveness of lenses intended to slow the progression of myopia. The present disclosure seeks to address this and aims to provide a set of lenses that can be used in young subjects that will prevent or slow the progression of myopia.

[0010] According to a first aspect, the present invention provides a set of contact lenses for use in preventing or slowing the progression or worsening of myopia, each contact lens in the set having an optical zone and a peripheral zone surrounding the optical zone. The peripheral zone of each contact lens has a graduated thickness profile configured to control rotation of the contact lens. The optical zone of each contact lens has a central region. The central region has a first optical axis and a curvature providing a base power. The optical zone of each contact lens has an annular region circumferentially surrounding the central region, the annular region having a treatment zone, the treatment zone having a property that reduces contrast of an image produced by light passing through the central region and the treatment zone compared to an image of an object produced by light passing through only the central region. The treatment zone is rotationally positioned at a different angle about the optical axis of each contact lens in the set relative to the peripheral zone thickness profile.

[0011] According to a second aspect, the present invention provides a kit for use in arresting or slowing the progression or worsening of myopia, the kit comprising a pair of contact lenses according to the first aspect of the invention, packaging for providing the pair of contact lenses to a user, and instructions for wearing the contact lenses.

[0012] According to a third aspect, the present invention provides a method of manufacturing a set of contact lenses. The method includes forming a first contact lens having an optical zone and a peripheral zone surrounding the optical zone. The peripheral zone of each contact lens has a graduated thickness profile configured to control rotation of the contact lens. The optical zone of each contact lens has a central region having a first optical axis and a curvature providing a base power. The optical zone of each contact lens has an annular region circumferentially surrounding the central region, the annular region having a treatment zone having a property that reduces the contrast of an image produced by light passing through the central region and the treatment zone compared to an image of an object produced by light passing through only the central region. The method includes repeating the steps described above to form a second contact lens. The treatment zone is rotationally positioned at a different angle about the optical axis of the first contact lens and the second contact lens relative to the peripheral zone thickness profile.

[0013] According to a fourth aspect, the present invention provides a method of reducing the progression of myopia, the method comprising the step of providing a pair of contact lenses according to the first aspect of the invention to a myopic person, the contact lenses being capable of accommodating for a range of near vision distances.

[0014] It will of course be understood that features described in connection with one aspect of the invention may be incorporated in other aspects of the invention, for example a method of the invention may include features described in connection with an apparatus of the invention, or vice versa. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a schematic graph showing the decrease in modulation transfer function (MTF) with spatial frequency for an aberration-free lens with no ADD area and for a lens including an annular ADD area; [Diagram 2]1 is a schematic diagram showing the field of the eye divided into quadrants. [Figure 3(a)-3(c)] 1 is a diagram illustrating the effect of parallax between a lens and the lens wearer's pupil. [Figure 4] FIG. 1 is a schematic plan view of a pair of lenses according to one embodiment of the present invention, each having a treatment zone occupying approximately 50% of the area of ​​the annular region. [Diagram 5] FIG. 5 is a cross-sectional view of one of the lenses of FIG. [Figure 6] FIG. 1 is a schematic plan view of a set of seven lenses according to one embodiment of the present invention, each lens having a treatment zone extending approximately 50° around an annular region. [Figure 7] FIG. 1 is a schematic plan view of a pair of lenses according to one embodiment of the present invention, each lens having two treatment zones, each treatment zone covering one quadrant of the lens, and each treatment zone having a curvature that provides an add power. [Figure 8] 8 is a schematic cross-sectional view of the optical zone of a first lens of the lens set shown in FIG. 7 taken along line A-A. [Figure 9] 8 is a schematic cross-sectional view of the optical zone of a first lens of the lens set shown in FIG. 7 taken along line B-B. [Figure 10] FIG. 1 is a schematic plan view of a set of four lenses according to an embodiment of the present invention, each having a treatment zone that spans one quadrant of the lens, the treatment zone having a curvature that provides add power with an asymmetric power profile. [Figure 11] 11A-11D are graphs showing asymmetric power profiles as a function of θ for the annular regions of the four lenses in the lens set shown in FIG. [Figure 12] FIG. 1 is a schematic plan view of a set of four lenses according to one embodiment of the present invention, each having a treatment zone across one quadrant of the lens, each treatment zone having features that increase the scattering of light passing through that region. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] According to a first aspect, the present invention provides a set of contact lenses for use in preventing or slowing the progression or worsening of myopia, each contact lens in the set having an optical zone and a peripheral zone surrounding the optical zone. The peripheral zone of each contact lens has a graduated thickness profile configured to control rotation of the contact lens. The optical zone of each contact lens has a central region. The central region has a first optical axis and a curvature providing a base power. The optical zone of each contact lens has an annular region circumferentially surrounding the central region, the annular region having a treatment zone, the treatment zone having a property that reduces contrast of an image produced by light passing through the central region and the treatment zone compared to an image of an object produced by light passing through only the central region. The treatment zone is rotationally positioned at a different angle about the optical axis of each contact lens in the set relative to the peripheral zone thickness profile.

[0017] The term contact lens as used herein refers to an ophthalmic lens that can be placed on the anterior surface of the eye. As will be understood, such contact lenses provide clinically acceptable on-eye movement and do not become fixed in one or both of a person's eyes. The contact lens may be in the form of a corneal lens (e.g., a lens that rests on the cornea of ​​the eye). The contact lens may be a soft contact lens, such as a hydrogel contact lens or a silicone hydrogel contact lens.

[0018] The contact lenses of the present invention have an optical zone. The optical zone encompasses the portion of the lens that has optical functionality. The optical zone is configured to be positioned over the pupil of the eye during use. For the contact lenses of the present invention, the optical zone has a central region and an annular region surrounding the central region and including a treatment zone. In the context of the present disclosure, the annular region is a substantially annular region surrounding the optical zone. The annular region may be substantially circular or substantially elliptical in shape. The annular region may completely surround the optical zone. The annular region may partially surround the optical zone.

[0019] The treatment zone has properties that cause a reduction in the contrast of an image produced by light passing through the lens compared to an image produced by light passing through only the central region of the lens. In other words, the treatment zone causes a reduction in the contrast of an image produced by light passing through the lens compared to an image produced by light passing through the same lens without the treatment zone. The treatment zone may have contrast-reducing features provided on the surface of the lens. These features may cause additional scattering of light compared to light passing through the remainder of the annular region and the central region. Such features may diffract light differently compared to light passing through the remainder of the annular region and the central region. The treatment zone may have a curvature that causes light to refract differently than the remainder of the annular region and the central region, thereby causing a reduction in the contrast of an image produced by light passing through the lens.

[0020] The treatment zone may be a continuous zone. The treatment zone may be less than half the annular region. The treatment zone may extend over less than one-quarter of the annular region. The annular region may consist of a plurality of treatment zones. The contrast reduction may vary throughout the treatment zone of each lens. Each lens in the lens set may have the same treatment zone contrast reduction variation. The boundary between any of the treatment zones and the remainder of the annular region may be a sharp boundary or a smooth boundary. At the boundary between each treatment zone and the remainder of the annular region, a blending zone may be provided. The blending zone may have properties that cause a contrast reduction in an image produced by light passing through the lens compared to an image produced by light passing through a central region of the lens. Such properties may vary and may lose their contrast reducing effect moving from the treatment zone towards the annular region. For example, if the treatment zone has a curvature that provides the add power, the blend zone between the treatment zone and the remainder of the annular region may exhibit a gradual change in curvature, which may result in a gradual decrease in add power throughout the region. If the treatment zone has features that increase light scattering, the blend zone between the treatment zone and the remainder of the annular region may also have features that increase scattering, but the density of these features may vary throughout the blend zone.

[0021] The reduction in contrast of an image of an object produced by light passing through the central region and the treatment zone, compared to an image of the object produced by light passing through only the central region, can be quantified using the modulation transfer function (MTF).

[0022] A lens never perfectly reproduces the contrast of an object in the image of the object produced by the lens. The modulation transfer function (MTF) of a given lens measures the lens's ability to transfer contrast from an object to its image at a particular resolution, and can be derived from the Fourier transform of the point spread function or line spread function. To measure the MTF, a test object (imaged object) of black and white line pairs can be used. As the line spacing of the test object decreases (i.e., as the pairs of black and white lines get closer to each other, i.e., the spatial frequency increases), the line spread functions of the black lines start to overlap each other, and thus the difference between the black lines and their background decreases in the image, and the MTF decreases.

[0023] For lenses according to embodiments of the present invention, the presence of a treatment zone reduces the MTF (and therefore the contrast) of an image produced by light passing through the treatment zone and the central zone, compared to an image produced by light passing through only the central zone. This can be better understood with reference to FIG. 1. For an aberration-free lens without an add power area, the MTF decreases as a function of spatial frequency, as shown by curve A (dashed line). For lenses with an optical zone that includes an annular area with add power, an additional modulation is introduced into the MTF, as shown by curve B.

[0024] Thus, additional contrast attenuation can be said to be the result of the treatment zone having an add power.Alternatively, for example, the treatment zone may have features that result in increased light scattering.

[0025] For lenses embodying the present invention, the contrast attenuation caused by the treatment zone can result in a decrease in contrast for an image produced by light passing through the treatment zone and the central region compared to an image produced by light passing through only the central region.

[0026] The optical zone is surrounded by a peripheral zone. The edge zone may surround the peripheral zone. The peripheral zone is not part of the optical zone, but is located outside the optical zone and above the pupil when the lens is worn, and performs a mechanical function, such as increasing the size of the lens, making it easier to handle, providing ballast stability to prevent lens rotation, and / or providing a contoured area that increases comfort for the lens wearer. The peripheral zone may extend to the edge of the contact lens.

[0027] The contact lenses according to the embodiments of the present invention exhibit a peripheral zone thickness variation configured to control lens rotation. Each lens in a lens set may have the same peripheral zone thickness profile. The peripheral zone thickness variation may be configured to stabilize the lens in a particular orientation. The thickness variation may be a continuously varying thickness around the peripheral zone. The peripheral zone thickness may increase towards the bottom of the lens (considered to be in its normal orientation when worn by the wearer). The thickness variation may be due to the curvature of the anterior surface of the peripheral zone. The thickness variation may be due to the curvature of the posterior surface of the peripheral zone. The thickness variation may be due to a combination of the curvatures of the posterior and anterior surfaces of the peripheral zone. The peripheral zone thickness variation may be configured to facilitate lens rotation in a particular direction.

[0028] The thickness of the various regions of the peripheral zone can be selected using routine methods known to those skilled in the art. The thickness and configuration can be selected to achieve any desired amount of contact lens rotation on the eye without significantly reducing the comfort or lens wear of the contact lens. For example, for the design of the peripheral zone, contact lenses can be manufactured with a specific target design and thickness and clinically tested on human eyes. The amount of lens rotation can be observed by an eye care professional using a slit lamp or other conventional tools. Typically, a number of contact lenses with different thickness profiles are manufactured and tested on the eyes of many people (e.g., 20 or more) to evaluate the amount of lens rotation and lens comfort. If the amount of lens rotation is too little or too much, or if the lens comfort is significantly lower compared to the control lens, lenses with different thickness profiles in the peripheral zone are manufactured and tested.

[0029] The lens has one or more stabilizing features. For example, the lens may include a periballast, a prismatic ballast, or a dynamic stabilizing feature (e.g., two thin zones along the vertical meridian separating the upper and lower halves). The peripheral zone may include a ballast for orienting the lens when positioned on the wearer's eye. The ballast may be a prismatic ballast. When placed on the wearer's eye, the lens may rotate to a predetermined angle of repose under the action of the wearer's eyelid and as a result of gravity. The ballast may be a wedge, and the rotation may occur due to a rotational force exerted on the wedge by the wearer's eyelid. The prismatic ballast may be provided on the anterior surface of the lens. A contact lens with a prism ballast may have a uniform thickness extending in a horizontal band throughout the peripheral zone, where the horizontal band gradually increases from a small thickness in the upper portion of the lens to a relatively large thickness in the lower portion of the lens, and then tapers to a small thickness near the lower edge of the contact lens. As a frame of reference, the horizontal band is parallel to a horizontal line passing through the center of the contact lens when viewed in plan view and the upper portion of the lens is located at the top of the field of vision. In other words, the horizontal band is parallel to the 0° / 180° meridian of the contact lens, as will be understood by those skilled in the art. If the contact lens includes a dynamic stabilization feature, the contact lens may have upper and lower portions in the peripheral zone that are relatively thinner than the thickness of the peripheral zone along the 0° / 180° meridian of the contact lens. As an example, the stabilization feature may have a thickness of 50 to 100 micrometers in the upper region of the peripheral zone, which gradually increases toward the 0° / 180° meridian. The stabilizing feature has a dual thin zone, and the region of maximum thickness may be located near the 0° / 180° meridian and may range from 250 micrometers to 450 micrometers. If the stabilizing feature is a prism ballast, the thickness of the peripheral zone may continue to increase to a maximum thickness at a lower portion of the peripheral zone, which may be between about 250 micrometers and 450 micrometers. Rotation may also be assisted by gravity acting on the lens.Each lens in the lens set may exhibit the same peripheral zone thickness variation, or each lens in the lens set may exhibit a peripheral zone thickness variation that produces the same or a similar effect when the lenses are worn by a wearer. For example, each lens in the lens set may exhibit a peripheral zone thickness variation such that the lenses rotate to lie in the same orientation about the first optical axis when the lenses are worn by a wearer.

[0030] The contact lens may be substantially circular in shape and have a diameter of about 4 mm to about 20 mm, preferably about 13.0 mm to about 15.0 mm. When diameter is mentioned in this specification, it means chord diameter. The central thickness of the lens may be about 50 micrometers to about 300 micrometers. The peripheral zone of the lens may have a thickness of about 50 micrometers to about 450 micrometers. The thickness of the lens may be measured using conventional techniques and instruments, such as a Rehder instrument. The optical zone may be substantially circular in shape and have a diameter of about 2 mm to about 10 mm. In some embodiments, the diameter of the contact lens is 13 mm to 15 mm and the diameter of the optical zone is 7 mm to 9 mm.

[0031] The field of view of the eye can be divided into quadrants as shown in FIG. 2, which may also be used to describe the quadrants of a contact lens when positioned on the eye. The upper half of the eye / lens is the superior half 1, and the lower half is the inferior half 3. The field of view located closest to the nose is the nasal half 5, and the field of view located farther from the nose is the temporal half 7. Thus, the four quadrants can be defined as superior-nasal 9, superior-temporal 11, inferior-nasal 13, and inferior-temporal 15. In the following description, these definitions are used to describe the location of the add area and the change in thickness of the peripheral zone when the lens is in normal use and worn by the wearer.

[0032] According to embodiments of the present invention, for off-axis light entering the lens, light is approximately mapped from each quadrant of the lens wearer's visual field to the opposite quadrant of the retina. Parallax results from the axial separation of the lens and the position of the wearer's pupil when positioned on the anterior surface of the cornea, which causes the lens and pupil to shift relative positions as the viewing angle changes, or as the direction of light entering the lens changes. This is shown, by way of example, in Figures 3(a)-3(c), which show a lens 17 according to one embodiment of the present invention, having a treatment zone 19 spanning approximately half of the annular area (the temporal half). The iris 21 is shown diagrammatically as viewed through the cornea. As shown in Figure 4(b), the contrast reducing properties of the treatment zone 19 affect light imaged from the wearer's right visual field, but as shown in Figure 4(c), the contrast reducing properties of the treatment zone 19 do not affect light imaged from the wearer's left visual field. Light from the wearer's left visual field that passes through the treatment zone 19 is blocked by the iris 21. For this lens 17, the treatment zone 19 significantly reduces image contrast for the left retina (nasal retina for right eye, temporal retina for left eye) but not for the right retina (temporal retina for right eye, nasal retina for left eye). It is clear that if the treatment zone covers the nasal half of the lens instead of the temporal half, the lens will significantly reduce image contrast for the right (temporal) retina but not the left (nasal) retina. By placing the treatment zone 17 within the annular region of the lens, contrast attenuation can be targeted at the peripheral zone of the retina while minimizing interference with foveal vision.

[0033] For each lens in the lens set, the thickness variation of the peripheral zone may be symmetrical about a lens diameter line, where the lens diameter line divides the annular region into two halves and the treatment zone is restricted to one half of the annular region. The thickness variation may be substantially restricted to lie along the lens diameter line. The thickness variation of the peripheral zone may be used to control the location of the treatment zone relative to the wearer's retina when the lens is worn by the wearer.

[0034] The thickness variation in the peripheral zone may include a ballast, which may control the rotation of the lens. When the lens is in use, the lens may be rotated so that the ballast is at or near the bottom of the lens, i.e., in the lower half. The lens may be rotated so that the ballast is symmetrical about a line that divides the temporal and nasal halves of the lens.

[0035] The lens diameter should lie along a line separating the nasal and temporal halves of the lens.

[0036] For each lens in the lens set, the contrast reducing transitions of the treatment zone are rotationally positioned at different angles about the optical axis of each lens in the lens set relative to the thickness profile of the peripheral zone. For example, each lens in the lens set may have a treatment zone that occupies about 25% of the area of ​​the annular region. A first lens in the lens set may have a treatment zone across the inferior-temporal quadrants of the lens, a second lens in the lens set may have a treatment zone across the superior-temporal quadrants of the lens, a third lens in the lens set may have a treatment zone across the superior-nasal quadrants of the lens, and a fourth lens in the lens set may have a treatment zone across the inferior-nasal quadrants of the lens.

[0037] A lens set may, for example, consist of two lenses that are intended to be worn in rotation over a number of days.A lens set may, for example, consist of seven lenses that are intended to be worn in rotation on different days of the week.

[0038] Because each lens in the lens set has a treatment zone that is rotationally positioned at a different angle about the optical axis relative to the thickness profile of the peripheral zone, the treatment zone targets a different region of the retina when each lens in the lens set is worn by a wearer. Thus, sequential wear of each lens in the lens set may reduce the eye's ability to compensate for the contrast reducing effects of the treatment zone.

[0039] The first optical axis of the central region may be located along the centerline of the lens. The central region may focus light from a distant point object on the first optical axis to a spot on the first optical axis at the far focal plane. The term surface as used herein does not mean a physical surface, but a surface that can be drawn through a point to focus light from a distant object. Such a surface is also called an image surface (even though it may be a curved surface) or an image shell. The eye focuses light onto a curved retina, and in a perfectly focused eye, the curvature of the image shell matches the curvature of the retina. Thus, the eye does not focus light onto a flat mathematical plane. However, in the art, the curved surface of the retina is locally commonly referred to as a plane.

[0040] In embodiments, the treatment zone may be provided across a contiguous portion of the annular region of each lens. The treatment zone may occupy less than 50% of the area of ​​the annular region of each lens. The treatment zone may occupy less than 25% of the area of ​​the annular region of each lens. The treatment zone may occupy less than 10% of the annular region of each lens. In embodiments, multiple non-bonded treatment zones may be located across the annular region of each lens.

[0041] In embodiments in which each lens has multiple non-bonded treatment zones, the total area of ​​the non-bonded treatment zones for each lens may be less than 50% of the area of ​​the annular region. The total area of ​​the non-bonded treatment zones for each lens may be less than 25% of the area of ​​the annular region. The total area of ​​the non-bonded treatment zones for each lens may be less than 10% of the area of ​​the annular region. Each non-bonded treatment zone may span 5-10% of the circumference of the annular region. For each lens, each of the non-bonded treatment zones may be approximately equal in area. For each lens, the non-bonded treatment zones may be regularly spaced around the circumference of the annular region or may be irregularly spaced around the circumference of the annular region. The non-bonded portions may be separated by portions of the annular region that do not substantially reduce the contrast of an image of the object produced by light passing through the central region and the treatment zones compared to an image of the object produced by light passing through only the central region. The portions between the treatment zones may have a curvature that provides the base power.

[0042] The treatment zone of each lens in the lens set may have a strong contrast reduction region having a property of reducing the contrast of an image of an object produced by light passing through the central region and the treatment zone by 50% or more compared to an image of the object produced by light passing through only the central region. The strong contrast reduction region may reduce the contrast of an image produced by the lens by 75% or more. The treatment zone may further have a weak contrast reduction region that reduces the contrast of an image of an object produced by light passing through the central region and the treatment zone by less than 50% compared to an image of the object produced by light passing through only the central region. In embodiments in which each lens in the lens set has multiple treatment zones, any or all of the treatment zones may be strong contrast reduction regions. Any or all of the treatment zones may be weak contrast reduction regions.

[0043] The treatment zone of each lens may exhibit a change in curvature that provides an add power.

[0044] The anterior surface of the treatment zone may have a radius of curvature smaller than the radius of curvature of the anterior surface of the central region and the remainder of the annular region. Thus, the treatment zone may have a power greater than the base power of the central region and the remainder of the annular region. The focus of the treatment zone may be located on a near focal plane, and the focus of the central region and the remainder of the annular region may be located on a far focal plane, which is located far from the posterior surface of the lens. The focus of the treatment zone and the focus of the central region may share a common optical axis. For a point source located at infinity, the light rays focused by the central region and the annular region create a focused image at the far focal plane. The light rays focused by the central region also produce an unfocused blurred spot at the near focal plane.

[0045] For each lens, at least some of the add power may be provided by a curvature located on a center of curvature located a first distance from the first optical axis.

[0046] The light rays from the distant point source passing through the treatment zone may be focused on the add focal plane away from the first optical axis. The light rays passing through the central region may form an on-axis blurred circle (or an ellipse for a toric lens) at the maximum add focal plane. The light rays from the distant point source passing through the treatment zone may be focused outside the blurred circle or ellipse. The central region of the lens has a base power. If the treatment zone has an add power region, the net near power of the treatment zone is the sum of the base power and the add power. The center of curvature of the add power region may be located at a first distance from the first optical axis.

[0047] At least one ADD power area may be configured to produce a light distribution at the focal plane of the ADD power area that reproduces the arbitrary zone geometry of the ADD power area as a whole. The focal plane of the ADD power area is defined by a plane passing through the point where the light passing through the ADD power area is focused. For an ADD power area over a portion of an annular area, a focusing arc may be produced at the focal plane of the ADD power area. The curvature of the treatment zone or portion may be selected to position the light focused at the treatment zone focal plane at a distance of about 2 micrometers to about 700 micrometers, preferably about 20 micrometers to about 300 micrometers, from the optical axis and perpendicular to the optical axis.

[0048] The treatment zone of the annular region may have a width, and a normal to the surface of the treatment zone taken at half the width of the treatment zone may intersect a normal taken at the center of curvature of the surface of the central region. The treatment zone may thereby focus light from each distant point object to produce a focusing arc at the near focal plane, the arc being outside and surrounding the blurred circle produced by the light focused by the central region. The surface of the treatment zone may be the anterior surface. The surface of the central region may be the anterior surface. The surface of the treatment zone may be a surface having a curvature that provides an add power. The surface of the central region may be a surface having a curvature that provides a base power.

[0049] The base power of the lens may be positive, and the treatment zone may have a power that is more positive than the base power. In this case, the focal plane of maximum add power is located closer to the lens than the far focal plane. No on-axis image is created by the light passing through the treatment zone. Thus, the lens wearer must use the natural accommodation of his or her eye to focus on nearby objects. Most likely, the light rays focused by the treatment zone do not intersect the first optical axis of the contact lens at all, or not until after such light rays have passed through the add focal plane.

[0050] The base power of the lens can be negative, and the treatment zone can be less negative than the power of the base region, or the treatment zone can have a positive power. Considering the lens being positioned on the cornea, if the power of the treatment zone is less negative than the base power, the add focal plane will be located further forward in the eye than the far focal plane. Considering the lens not being positioned on the cornea, if the power of the treatment zone is positive, the add focal plane will be located on the opposite side (image side) of the lens than the far focal plane (which is the virtual focal plane on the object side of the lens for the negative base power), and if the power of the treatment zone is negative (but less negative than the base power), the virtual add focal plane will be located farther away from the lens than the virtual far focal plane.

[0051] Since each lens in the lens set has the treatment zone add power that is rotationally positioned at a different angle around the optical axis relative to the thickness profile of the peripheral zone, each lens in the set directs the add power toward a different area of ​​the retina periphery. Thus, when the lenses are worn by the wearer at different times, the add power will be directed at different areas of the retina at different times. This is particularly beneficial for hydrogel and silicone hydrogel lenses, because it is believed that over time, the eye will adapt to the blur at the add focal plane, thereby reducing the effectiveness of the add treatment zone in preventing myopia from worsening. By wearing different lenses from the lens set consecutively, thereby providing add power targeted at different areas of the retina at different times, the lenses may reduce the eye's ability to compensate for blur over time. When different lenses in the set are worn, different portions of the retina are subjected to different amounts of defocus, which may be more effective at slowing the progression of myopia than wearing a single lens providing a constant myopic defocus.

[0052] In embodiments in which each lens in a lens set has multiple treatment zones, each of the treatment zones of a given lens may have a curvature that provides the same add power, or each of the treatment zones of a given lens may have a curvature that provides a different add power.

[0053] The treatment zone of each lens may have an asymmetric power profile. For each lens in the lens set, the curvature providing the ADD power may be the curvature of the anterior surface of the lens. For each lens, the curvature providing the ADD power may be the curvature of the posterior surface of the lens. For each lens, the curvature providing the ADD power may be the curvature of the anterior and posterior surfaces of the lens that provide a combined effect.

[0054] For lenses used in the treatment of myopia, the base power may be negative or close to zero, and the central region corrects distance vision. The base power may be between 0.5 diopters (D) and -20.0 diopters. The base power may be between -0.25 diopters and -20.0 diopters. The add power is defined as the difference between the base power and the power of the add apex. For each lens in the lens set, the add power provided by each treatment zone may be between +0.5 and +10.0 D, preferably between +2.0 and +3.0 D. For lenses with a positive base power, the power of each of the add power regions is more positive than and similar to the base power. For lenses with a negative base power, the power of each of the add power regions may be less negative than the base power, or the power of any add power region may be a positive power. The net power of the annular area of ​​any ADD power area is the sum of the base power and the ADD power.

[0055] The treatment zone of each lens may include features that increase the scattering of light passing through the treatment zone compared to light passing through only the central region. Such features may be provided on the annular region's anterior surface. The treatment zone of each lens may include optical elements baked into or etched into the lens's surface. The features that increase the scattering of light passing through the treatment zone reduce the contrast of an image produced by light passing through the treatment zone and the central region compared to an image produced by light passing through only the central region. When different lenses in the set are worn by a wearer, the high scattering regions direct light toward different regions of the retina. This may reduce the eye's ability to compensate for the reduction in contrast caused by scattering.

[0056] The treatment zone may have a curvature that provides an add power, where the center of curvature is located on the first optical axis.

[0057] The treatment zone may include features that cause diffraction of light passing through the treatment zone, and may include other features that reduce the contrast of an image produced by light passing through the treatment zone and the central region compared to an image produced by light passing through only the central region.

[0058] The annular region of each lens may have a substantially circular periphery. The annular region of each lens may have a substantially elliptical periphery. The central region of each lens may be substantially circular in shape, the central region may have a diameter of about 2-7 mm, preferably 2-5 mm. The central region may be substantially elliptical in shape. The base curve may have a radius of curvature of about 8.0 mm-9.0 mm. The annular region of each lens may extend radially outwardly from the periphery of the central region by 0.1 mm to about 4 mm, preferably 0.5 mm-1.5 mm. The periphery of the central region of each lens may define a boundary between the central region and the annular region, such that the annular region is located adjacent to the central region.

[0059] The annular region of each lens may abut the central region. A hybrid zone may be provided between the central region and the annular region. The hybrid zone should not substantially affect the optical properties provided by the central and annular regions, and may have a radial width of 0.05 mm or less, although in some embodiments the hybrid zone may have a width as wide as 0.2 mm or as wide as 0.5 mm.

[0060] The annular region may extend radially outwardly to abut the peripheral zone, and the treatment zone may span the radial width of the annular region.

[0061] Each lens in the lens set may have a plurality of concentric annular regions, each of which may be an annular region that includes a treatment zone with the characteristics described above.

[0062] The central region of each lens has a base power, which in the context of the present invention is defined as the average absolute refractive power of the central region. Any base power meridian also has a base power. The base power corresponds to the refractive power of the contact lens provided on the contact lens packaging (although in practice this may not have the same value). Thus, the lens powers given herein are nominal powers. These values ​​may differ from the lens power values ​​obtained by direct measurement of the lens, and these values ​​reflect the lens powers used to provide the required prescription power when used in ophthalmic treatment.

[0063] Each lens may be comprised of an elastomeric material, a silicone elastomeric material, a hydrogel material, or a silicone hydrogel material, or a mixture thereof.

[0064] As understood in the field of contact lenses, a hydrogel is a material that retains water at equilibrium and is free of silicone-containing chemicals. A silicone hydrogel is a hydrogel that includes silicone-containing chemicals. The hydrogel and silicone hydrogel materials described in the context of the present invention have an equilibrium water content (EWC) of at least 10% to about 90% (w / w). In some embodiments, the EWC of the hydrogel or silicone hydrogel material is about 30% to about 70% (w / w). To illustrate a comparative example, the silicone elastomer materials described in the context of the present invention have a water content of about 0% to less than 10% (w / w). Typically, the silicone elastomer materials used in the methods or devices of the present invention have a water content of 0.1% to 3% (w / w). Examples of suitable lens formulations include those having the following United States Adequate Names (USAN): methafilcon A, ocufilcon A, ocufilcon B, ocufilcon C, ocufilcon D, omafilcon A, omafilcon B, comfilcon A, enfilcon A, stenfilcon A, fanfilcon A, etafilcon A, ) A, senofilcon A, senofilcon B, senofilcon C, narafilcon A, narafilcon B, balafilcon A, samfilcon A, lotrafilcon A, lotrafilcon B, somofilcon A, riofilcon A, delefilcon A, verofilcon A, kalifilcon A, and the like.

[0065] Alternatively, each lens may comprise, consist essentially of, or consist of a silicone elastomer material. For example, the lenses may comprise, consist essentially of, or consist of a silicone elastomer material having a Shore A hardness of 3 to 50. The Shore A hardness can be determined using conventional methods (e.g., using method DIN 53505), as will be appreciated by those skilled in the art. Other silicone elastomer materials can be obtained, for example, from NuSil Technology or Dow Chemical Company.

[0066] According to a second aspect, the invention includes a kit for use in preventing or slowing the progression or worsening of myopia. The kit includes a set of contact lenses having any of the characteristics described above. The kit includes packaging for providing the set of contact lenses to a user. The kit includes instructions for wearing the lenses. Each lens in the set may be individually packaged, for example blister packed. The packaging may consist, for example, of a strip of blister packets bonded together. The set of lenses may be a set of two lenses that can be rotated for use over a number of days. The set of lenses may be a set of seven lenses that can be rotated for use on each day of the week. The instructions may instruct the wearer to wear a different lens each day or after a certain number of hours or days. The instructions may be provided on the packaging or on the lenses. The kit may further include a second set of lenses having any of the characteristics described above. Each lens in the first set of lenses has a treatment zone rotationally positioned at a first angle about the first optical axis relative to the peripheral zone thickness profile. For each lens in the first set of lenses, there can be a corresponding contact lens in a second set of contact lenses having a treatment zone positioned at an equal but opposite angle about the first optical axis relative to the peripheral zone thickness profile. The first set of lenses can be a set of lenses for the wearer's left eye and the second set of lenses can be a set of lenses for the wearer's right eye, or vice versa.

[0067] According to a third aspect, the present invention provides a method of manufacturing a set of contact lenses. The method includes forming a first contact lens having an optical zone and a peripheral zone surrounding the optical zone. The peripheral zone of each contact lens has a graduated thickness profile configured to control rotation of the contact lens. The optical zone of each contact lens has a central region, the central region having a first optical axis and a curvature providing a base power. The optical zone of each contact lens has an annular region, the annular region circumferentially surrounding the central region, the annular region having a treatment zone, the treatment zone having a property that reduces the contrast of an image produced by light passing through the central region and the treatment zone compared to an image of an object produced by light passing through only the central region. The method includes repeating the steps described above to form a second contact lens. The treatment zone reduction transition is rotationally positioned at a different angle about the optical axis of the first contact lens and the second contact lens relative to the peripheral zone thickness profile. The method may include repeatedly performing the above steps to form a set of contact lenses, wherein the treatment zone of the annular region exhibiting a contrast reducing change is rotationally positioned at a different angle about the optical axis of each of the contact lenses in the set relative to the peripheral zone thickness profile.

[0068] The second lens, and any subsequent lenses, should exhibit the same peripheral zone thickness profile as the first lens, and the same treatment zone contrast reduction change as the first lens.

[0069] Each lens in a lens set, and each lens set, may include any of the characteristics described above.

[0070] The manufacturing method may include forming a female mold member having a concave lens-forming surface and a male mold member having a convex lens-forming surface. The method may include filling a gap between the female mold member and the male mold member with bulk lens material. The method may further include curing the bulk lens material to form a lens.

[0071] The contact lenses may be formed using a lathing process. The lenses may be formed by a cast molding process, a rotational molding process, or a lathing process, or a combination thereof. As will be understood by those skilled in the art, cast molding refers to forming a lens by placing a lens-forming material between a female mold member having a concave lens member-forming surface and a male mold member having a convex lens member-forming surface.

[0072] In a fourth aspect of the invention, there is also provided a method of using a set of contact lenses as described herein. The method may be effective in reducing the progression of refractive errors, for example, reducing the progression of myopia. When the lenses of the invention are used to reduce the progression of myopia, the method includes providing the contact lenses to a person whose eyes can accommodate a range of near vision distances, for example, ranging from about 15 cm to about 40 cm. Some embodiments of the method include providing the ophthalmic lenses to a person between about 5 and about 25 years of age. The providing step may be performed by an eye care professional, such as an optician or optometrist. Alternatively, the providing step may be performed by a lens distributor who arranges for delivery of the ophthalmic lenses to the lens wearer.

[0073] FIG. 4 illustrates a set of contact lenses 200 for use in slowing myopia progression (e.g., myopia control) in accordance with an embodiment of the present invention. The set includes two lenses 201a, 201b. Each lens 201a, 201b has an optical zone 202a, 202b that generally covers the pupil, and a peripheral zone 204a, 204b that is located above the iris. The peripheral zones 204a, 204b provide mechanical functions, including providing a contoured area that increases the size of the lenses 201a, 201b, thereby making them easier to handle and improving comfort for the lens wearer. The peripheral zones 204a, 204b increase in thickness toward the bottom of the lens to provide ballast 209a, 209b. In the exemplary diagrams shown and described herein, the location of the thickest portion of the ballast is indicated by a triangle, but those skilled in the art will understand that the thickness change can be implemented by different types of ballast or other thickness changes (see, for example, paragraph

[0027] ). For each lens 201a, 201b in the set, the thickness change in the peripheral zone 204a, 204b is the same. For both lenses 201a, 201b in the set, the ballast 209a, 209b is positioned at the bottom of the lens (i.e., in the lower half), along the diametric line separating the temporal and nasal halves of the lenses 201a, 201b. The ballasts 209a, 209b control the rotation of the lenses 201a, 201b so that when the lenses 201a, 201b are worn, they remain in a stable position despite rotational forces caused by the wearer blinking. The optical zones 202a, 202b provide the optical functionality of the lenses 201a, 201b. Each optical zone 202a, 202b has an annular region 203a, 203b and a central region 205a, 205b.Each annular region 203a, 203b has a treatment zone 207a, 207b that reduces the contrast of an image of an object produced by light passing through the central region 205a, 205b and the treatment zone 207a, 207b compared to an image of the object produced by light passing only through the central region 205a, 205b. Of the lenses 201a, 201b in this set 200, the first lens 201a has a treatment zone 207a over the temporal half of the lens 201a and the second lens 201b has a treatment zone 201b over the nasal half of the lens 201a.

[0074] The position around the circumference of the lens can be determined by an angle θ, as shown in FIG. 4, where θ is between 0° and 360°. For the two lenses 201a, 201b in the set, the treatment zones 207a, 207b are rotationally positioned at various angles about the optical axis relative to the ballasts 209a, 209b, with the treatment zone 207a of the first lens 201a spanning approximately 0° to 180° and the treatment zone 207b of the second lens spanning approximately 180° to 360°. If a wearer wears the two lenses 201a, 201b in rotation over a number of days, the treatment zones 207a, 207b will target different areas of the retina at different times. This may reduce the eye's ability to compensate for the contrast-reducing effect of the treatment zones.

[0075] For the lens set of FIG. 4, the treatment zone has a change in curvature that provides an add power. FIG. 5 is a cross-sectional view of the lens 201a of FIG. 4. The anterior surface of the treatment zone 207a has a radius of curvature that is smaller than the radius of curvature of the anterior surface of the central region 205a and the remainder of the annular region 203a. Thus, the treatment zone 207a has a power that is greater than the base power of the central region 205a and the remainder of the annular region 203a. The focus of the treatment zone 207a is located on a near focal plane 222 (shown in dashed lines), and the focus of the central region 205a and the remainder of the annular region 203a is located on a far focal plane 224 that is located away from the posterior surface of the lens 201a. The focus of the treatment zone 207a and the focus of the central region 205a may share a common optical axis 218. For a point source located at infinity, the light rays focused by the central region 205a and the annular region 203a produce a focused image at the far focal plane 224. The light rays focused by the central region 205a also produce an unfocused, blurry spot at the near focal plane 222.

[0076] FIG. 6 illustrates a set of contact lenses 300 for use in slowing myopia progression (e.g., myopia control) in accordance with one embodiment of the present invention. The set includes seven lenses 301a-g. As in FIG. 4, each lens 301a-g has an optical zone 302a-g that generally covers the pupil, and a peripheral zone 304a-g that is located over the iris. The peripheral zones 304a-g serve mechanical functions, including providing a contoured area that increases the size of the lenses 301a-g, thereby making them easier to handle and improving comfort for the lens wearer. The peripheral zones 304a-g exhibit thickness variation provided by ballasts 309a-g. For each lens 301a-g in the set, the thickness variation of the peripheral zones 304a-g is the same. For each of the lenses 301a-301g in the set, the ballast 309a-309g is positioned at the bottom (i.e., lower half) of the lens along a diametric line separating the temporal and nasal halves of the lens 301a-301g. The ballast 309a-309g controls the rotation of the lenses 301a-301g so that when the lenses 301a-301g are worn, they remain in a stable position despite rotational forces caused by the wearer blinking. The optical zones 302a-302g provide the optical functionality of the lenses 301a-301g. Each optical zone 302a-302g has an annular region 303a-303g and a central region 305a-305g. Each annular region 303a-303g has a treatment zone 307a-307g that reduces the contrast of an image of an object produced by light passing through the central region 305a-305g and the treatment zone 307a-307g compared to an image of the object produced by light passing only through the central region 305a-305g.By positioning the lenses 301a-301g around the circumference by an angle θ (where theta is 0°-360° in this case), the first lens 301a has a treatment zone 307a that spans approximately 0°-50° along the annular region 303a, and the second lens 301b has a treatment zone 307b that spans approximately 50°-100°. Each lens 301a-301g in the set has a treatment zone 307a-307g that spans a different sector of the annular region 303a-303g relative to the ballast 309a-309g. If a wearer rotates between the lenses 301a-301g over multiple days, the treatment zones 307a-307g will target different areas of the retina at different times.

[0077] FIG. 7 illustrates a set of contact lenses 400 for use in slowing myopia progression (e.g., myopia control) in accordance with an embodiment of the present invention. The set includes two lenses 401a, 401b. As in FIG. 4, each lens 401a, 401b has an optical zone 402a, 402b that generally covers the pupil, and a peripheral zone 404a, 404b that is located over the iris. The peripheral zones 404a, 404b provide mechanical functions, including providing a contoured area that increases the size of the lenses 401a, 401b, thereby making them easier to handle and improving comfort for the lens wearer. The peripheral zones 404a, 404b exhibit thickness variations provided by ballasts 409a, 409b. For each lens 401a, 401b in the set, the thickness variations of the peripheral zones 404a, 404b are the same. For each of the lenses 401a, 401b in the set, the ballast 409a, 409b is positioned at the bottom (i.e., lower half) of the lens along a diametric line separating the temporal and nasal halves of the lens 401a, 401b. The ballast 409a, 409b controls the rotation of the lenses 401a, 401b so that when the lenses 401a, 401b are worn, they remain in a stable position despite rotational forces caused by the wearer blinking. The optical zones 402a, 402b provide the optical functionality of the lenses 401a, 401b. Each optical zone 402a, 402b has an annular region 403a, 403b and a central region 405a, 405b. Each annular region 403a, 403b has two treatment zones 407a, 407b, 407a', 407b' which reduce the contrast of an image of an object produced by light passing through the central region 405a, 405b and the treatment zones 407a, 407b, 407a', 407b' compared to an image of the object produced by light passing only through the central region 405a, 405b.By positioning the lenses 401a, 401b around the circumference by an angle θ (where theta is between 0° and 360°), the first lens 401a has a first treatment zone 407a in the superior-temporal quadrant along the annular region 403a, or extending between 270° and 360°, and a second treatment zone 407a' in the inferior-nasal quadrant along the annular region 403a, or extending between 90° and 180°. The second lens 401b has a first treatment zone 407b in the superior-nasal quadrant along the annular region 403b, or extending between 0° and 90°, and a second treatment zone 407b' in the inferior-temporal quadrant along the annular region 403b, or extending between 180° and 270°.

[0078] Each lens 401a, 401b in the set 400 has two treatment zones 407a, 407b, 407a', 407b', each of which spans a different sector of the annular region 403a, 403b relative to the ballast 409a, 409b. If a wearer wears the lenses 401a, 401b in rotation over multiple days, the treatment zones 407a, 407b, 407a', 407b' will target different areas of the retina at different times.

[0079] For the lenses 401a, 401b of Figure 7, each treatment zone 407a, 407b, 407a', 407b' has a curvature that provides an add power. For each lens, the central region 405a, 405b provides a base power and has a curvature centered on a center of curvature located on the first optical axis 418. This is illustrated in Figure 8, which is a schematic cross-sectional view of the first lens 407a in the set taken along line A-A.

[0080] Each treatment zone 407a, 407a' has a curvature that provides an add power. The radius of curvature 406a of the anterior surface of the treatment zone 407a, 407a' (shown as a dashed circle) is smaller than the radius of curvature 410 of the anterior surface of the central region 405a (shown as a dashed circle). Thus, the treatment zones 407a, 407a' have a power that is greater than the base power of the central region 405. Each of the treatment zones 407a, 407a' has the same anterior curvature and the same power. As shown in FIG. 8, the focal points of the treatment zones 407a, 407a' are located on the near focal plane 422, and the focal point of the central region 405a is located on the far focal plane 424, which is located far from the posterior surface of the lens 401a. The focal points 425 of the treatment zones 407a, 407a' and the focal point 424 of the central region 405a share a common optical axis 418. For a point source at infinity, the light rays focused by the central region 405a produce a focused image at the far focal plane 424. The light rays focused by the central region 405a also produce an unfocused, blurred spot at the near focal plane 422. The light rays focused by the treatment zones 407a, 407a' produce a focused image at the near focal plane 422. The light rays 420 focused by the treatment zones 407a, 407a' diverge after the near focal plane 422.

[0081] The add power treatment zones 407a, 407a' reduce the contrast of an image of an object produced by light passing through the central region and the treatment zones compared to an image of the object produced by light passing only through the central region 405. Between the treatment zones 407a, 407a' are regions that do not significantly reduce the contrast of an image produced by light passing through the lens 401. With respect to the lens 401a of Figure 7, these regions have base powers and light passing through these regions is focused at the far focal plane 424 as shown in Figure 9, which is a cross-sectional view of the lens 401a taken along line B-B.

[0082] The second lens 401b in the set 400 has treatment zones 407b, 407b' that span opposing quadrants. Thus, if a wearer were to rotate between wearing the two lenses 401a, 401a' on both days, on the first day the treatment zones 407a, 407a' of the first lens 401a would target the ADD power to the first two quadrants (in this case the inferior-nasal and superior-temporal quadrants), and on the next day the treatment zones 407b, 407b' of the second lens 401b would target the ADD power to the next two different quadrants (in this case the inferior-temporal and superior-nasal quadrants).

[0083] In the embodiment shown in Figure 7, the two treatment zones of each lens have the same power. In other embodiments, the two treatment zones may have different powers.

[0084] FIG. 10 illustrates a set of contact lenses 500 for use in slowing the progression of myopia (e.g., providing myopia control) in accordance with one embodiment of the present invention. The set 500 includes four lenses 501a-501d. Each lens 501a-501d has an optical zone 502a-502d that generally covers the pupil, and a peripheral zone 504a-504d that is located over the iris. The peripheral zones 504a-504d provide mechanical functions, including providing contoured areas that increase the size of the lenses 501a-501d, thereby making the lenses 501a-501d easier to handle and improving comfort for the lens wearer. The peripheral zones 504a-504d exhibit thickness variations provided by ballasts 509a-509d. For each lens 501a-501d in the set, the thickness variations of the peripheral zones 504a-504d are the same. For each of the lenses 501a-501d in the set, the ballast 509a-509d is positioned at the bottom (i.e., lower half) of the lens 501a-501d along a diametric line separating the temporal and nasal halves of the lens 501a-501d. The ballast 509a-509d controls the rotation of the lenses 501a-501d so that when the lenses 501a-501d are worn, they remain in a stable position despite rotational forces caused by the wearer blinking. The optical zones 502a-502d provide the optical functionality of the lenses 501a-501d. Each optical zone 502a-502d has an annular region 503a-503d and a central region 505a-505d. Each annular region 503a-503d has a treatment zone 507a-507d that reduces the contrast of an image of an object produced by light passing through the central region 505a-505d and the treatment zone 507a-507d compared to an image of the object produced by light passing only through the central region 505a-505d. The contrast reduction varies with the meridian around the annular region 503a-503d.By defining the circumferential position of the lenses 501a-501d by an angle θ (where theta is 0°-360° in this case), the first lens 501a has a first treatment zone 507a in the superior-temporal quadrant along the annular region 503a, or extending from 270°-360°; the second lens 501b has a second treatment zone 507b in the superior-nasal quadrant along the annular region 503b, or extending from 0°-90°; the third lens 501c has a treatment zone 507c in the inferior-nasal quadrant along the annular region 503c, or extending from 90°-180°; and the fourth lens 501d has a treatment zone 507d in the inferior-temporal quadrant along the annular region 503d, or extending from 180°-270°.

[0085] Thus, each lens 501a-501d in the set has a treatment zone 507a-507d that spans a different segment of the annular region 503a-503d relative to the ballast 509a-509d. When a wearer rotates between wearing the lenses 501a-501d over multiple days, the treatment zones 507a-507d will target different areas of the retina.

[0086] For the lenses 501a-501d of Figure 10, each treatment zone 507a-507d has a curvature that provides an add power. For each lens, the central region 505 has a curvature that provides a base power and is centered on the first optical axis.

[0087] Each treatment zone 507a-507d has a curvature that provides an add power. The radius of curvature of the anterior surface of the treatment zones 507a-507d is smaller than the radius of curvature of the anterior surface of the central regions 505a-505d. Thus, the treatment zones 507a-507d have a power greater than the base power of the central regions 505a-505d. Each of the treatment zones 507a-507d has the same anterior curvature and the same power, and each of the treatment zones has an asymmetric anterior surface curvature, which results in an asymmetric power profile. An example asymmetric power profile is shown for each lens in the set 500 in Figures 11(a)-11(d). For each lens 501a-501d, the treatment zones 507b-507d are rotated 90° around the annular regions 503(a)-503(d).

[0088] FIG. 12 illustrates a set of contact lenses 600 for use in slowing the progression of myopia (e.g., controlling myopia) in accordance with one embodiment of the present invention. The set 600 is similar to the set of lenses illustrated in FIG. 10. However, for this set of lenses 601a-601d, each of the treatment zones 607a-607d has features 608a-608d that increase the scattering of light that passes through the treatment zones 607a-607d relative to light that passes through the remainder of the annular regions 603a-603d and the central regions 605a-605d. This reduces the contrast of an image of an object, thereby reducing the contrast of an image produced by light that passes through the central regions 605a-605d and the treatment zones 607a-607d relative to an image of an object produced by light that passes only through the central regions 605a-605d. When a wearer cycles through the lenses 601a-601d, the treatment zones 607a-607d may target different areas of the retina, which may reduce the eye's ability to compensate for the contrast-reducing effects of the treatment zones.

[0089] In the embodiment shown in Figure 12, the light scattering features are provided in a treatment zone that spans a single quadrant of the annular region of each lens, although it will be appreciated that such features may be provided in lenses having any other form of treatment zone that falls within the scope of the claimed invention.

[0090] In another embodiment (not shown), each lens in the lens set may include two concentric annular regions, each of which may be an annular region that includes a treatment zone, as described above.

[0091] In other embodiments, the treatment zone may have properties that reduce the light contrast of an image produced by light passing through the central region and the treatment zone compared to an image of the object produced by light passing through only the central region, by causing a diffraction effect.

[0092] As will be appreciated, a wearer may be provided with one set of lenses for the right eye and one set for the left eye. Given a pair of lenses (right and left) that may be worn on a given day, both lenses may have treatment zones that span the same half or quadrant of the annular region. For example, both lenses may have treatment zones that span the temporal half of the lens and target the nasal retina. The treatment zone of the right lens provides a strong contrast reduction effect on the left retina of the right eye. The treatment zone of the left lens provides a strong contrast reduction effect on the right retina of the left eye. Correspondingly, the right lens provides a weak contrast reduction effect at the right retina of the right eye and the left lens provides a weak contrast reduction effect at the left retina of the left eye. Although the brain receives signals from both eyes and both areas of the retina, the weakly reduced contrast image dominates the binocular neural image in the cerebral cortex. Thus, at a perceptual level, image degradation can be avoided during normal binocular viewing.

[0093] In the above description, reference is made to integers or elements having known obvious or foreseeable equivalents, and such equivalents are hereby set forth as if they were individually set forth. Reference should be made to the claims which define the true scope of the invention, which should be deemed to include any such equivalents. The reader will also appreciate that any integers or features of the present disclosure described as advantageous, convenient, etc. are optional and do not limit the scope of the independent claims. It should further be understood that, while considered beneficial in some embodiments of the invention, such optional integers or features may not be desirable and therefore may not be recited in other embodiments.

Claims

1. A kit for use in preventing or slowing the progression or worsening of myopia, the kit comprising: The method includes: providing a first set of contact lenses, each contact lens in the first set having an optical zone and a peripheral zone surrounding the optical zone, the peripheral zone of each contact lens having a graduated thickness profile configured to control rotation of the plurality of contact lenses; and providing the optical zone of each contact lens having: a central region having a first optical axis and a curvature providing a base power, the first optical axis being located along a central axis of the plurality of contact lenses, the central region having a focal point located on the first optical axis in a far focal plane; and a treatment zone having a property of reducing contrast of an image produced by light passing through the central region and the treatment zone compared to an image of the object produced by light passing through only the central region; the treatment zone of each contact lens has an add power region with a curvature providing an add power, light from each distant point object is focused by the treatment zone to form a focusing arc at a near focal plane, the near focal plane being closer to the posterior surface of the plurality of contact lenses than the far focal plane, the focusing arc being outside of and surrounding a blurred circle formed by the light focused by the central region; a second set of contact lenses having characteristics of the first set of contact lenses, wherein for each contact lens in the first set of contact lenses having a treatment zone rotationally positioned at a first angle about the first optical axis relative to the peripheral zone thickness profile, there is provided a corresponding contact lens in the second set of contact lenses having a treatment zone positioned at an equal but opposite angle about the first optical axis relative to the peripheral zone thickness profile, wherein the first set of contact lenses is a set of contact lenses for a left eye of a wearer and the second set of contact lenses is a set of contact lenses for a right eye of the wearer, or the first set of contact lenses is a set of contact lenses for a right eye of a wearer and the second set of contact lenses is a set of contact lenses for a left eye of the wearer.

2. 10. The kit of claim 1, wherein the treatment zone of each contact lens is located on a continuous portion of the annular region of each contact lens, and the treatment zone occupies no more than 50% of the area of ​​the annular region of each contact lens.

3. 10. The kit of claim 1, wherein a plurality of non-bonded treatment zones occupy the area of ​​the annular region of each contact lens.

4. 2. The kit of claim 1, wherein the treatment zone of each contact lens has a change in curvature that provides an add power, and in each contact lens, at least some of the add power is provided by a curvature located on a center of curvature of the add power area, the center of which is located a first distance from the first optical axis.

5. 5. The kit of claim 4, wherein the treatment zone of each contact lens has an asymmetric power profile about the first optical axis.

6. 5. The kit of claim 4, wherein for each contact lens, the curvature providing the add power is the curvature of the anterior surface of the plurality of contact lenses.

7. 5. The kit of claim 4, wherein the add power provided by the treatment zone of each contact lens is between +0.5 and +10.0D.

8. 10. The kit of claim 1, wherein the treatment zone of each contact lens includes scattering features that increase scattering of light passing through the treatment zone compared to light passing through only the central region, the scattering features including or located on the anterior surface of the annular region.

9. The kit of claim 1 , wherein the annular region of each contact lens has a circular periphery.

10. The kit of claim 1 , wherein the annular region of each contact lens has an elliptical periphery.

11. 10. The kit of claim 1, wherein the central region of each contact lens is circular in shape and has a diameter of 2 to 7 mm.

12. 10. The kit of claim 1, wherein the annular region of each contact lens extends radially outward from the periphery of the central region by 0.5 mm to 1.5 mm.

13. 10. The kit of claim 1, wherein each contact lens is comprised of an elastomeric material, a silicone elastomeric material, a hydrogel material, or a silicone hydrogel material, or a mixture thereof.

14. The kit of claim 1 , wherein the graduated thickness profile of each peripheral zone is a prismatic ballast.

15. a packaging material for providing the set of contact lenses to a user; 10. The kit of claim 1, further comprising: instructions for wearing the plurality of contact lenses.

16. 16. The kit of claim 15, wherein the instructions are provided on the packaging material or on the plurality of contact lenses.

17. 10. A method for manufacturing a first set of contact lenses and a second set of contact lenses for use in the kit of claim 1, said method comprising: (a) forming a first contact lens for the first set of contact lenses, the plurality of contact lenses having an optical zone and a peripheral zone surrounding the optical zone, the peripheral zone of each contact lens having a graduated thickness profile configured to control rotation of the plurality of contact lenses, the optical zone of each contact lens comprising: a central region having a first optical axis and a curvature providing a base power, the first optical axis being located along a central axis of the plurality of contact lenses, the central region having a focal point located on the first optical axis in a far focal plane; and a treatment zone having a property of reducing contrast of an image produced by light passing through the central region and the treatment zone compared to an image of the object produced by light passing through only the central region; the treatment zone of each contact lens has an add power region with a curvature providing an add power, light from each distant point object is focused by the treatment zone to form a focusing arc at a near focal plane, the near focal plane being closer to the posterior surface of the plurality of contact lenses than the far focal plane, the focusing arc being outside of and surrounding a blurred circle formed by the light focused by the central region; (b) repeatedly performing step (a) to form a second contact lens in the first set, wherein the treatment zone is rotationally positioned at a different angle about the first optical axis of the first contact lens and the second contact lens relative to the peripheral zone thickness profile; (c) repeatedly performing steps (a) and (b) to form a second set of contact lenses, the second set of contact lenses having the characteristics of step (a) of the first set of contact lenses, the second set of contact lenses having a treatment zone rotationally positioned at a first angle about the first optical axis relative to the peripheral zone thickness profile, the treatment zone being positioned at an equal but opposite angle about the first optical axis relative to the peripheral zone thickness profile for each contact lens in the first set of contact lenses. and a second set of corresponding contact lenses of the plurality of contact lenses having treatment zones defined therein, wherein the first set of contact lenses is a set of contact lenses for the wearer's left eye and the second set of contact lenses is a set of contact lenses for the wearer's right eye, or the first set of contact lenses is a set of contact lenses for the wearer's right eye and the second set of contact lenses is a set of contact lenses for the wearer's left eye.

Images