Lens assemblies and related methods used to suppress or slow the progression or worsening of myopia.

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 used to suppress or slow down the progression or worsening of myopia. The present disclosure also relates to a method of manufacturing such lenses and a method of using such lenses.

Background Art

[0002] Myopia (nearsightedness) affects a significant number of people, including children and adults. A myopic eye focuses incoming light from distant objects at a location in front of the retina. As a result, the light converges towards a plane located in front of the retina and diverges towards the retina, resulting in a lack of focus upon reaching the retina. Conventional lenses for correcting myopia (e.g., spectacle lenses or contact lenses) reduce the convergence of incoming light from distant objects (with respect to contact lenses) or cause divergence (with respect to spectacle lenses), after which the incoming light reaches the eye, and as a result, the position of the focus is shifted onto the retina.

[0003] Decades ago, it was suggested that to slow down or suppress the progression of myopia in children or young people, undercorrection should be used, i.e., the focus should be brought closer to the retina but not completely shifted onto the retina. However, as an inevitable result of this approach, visual acuity for distant objects is reduced compared to that obtained using lenses that fully correct myopia. Furthermore, it is now considered doubtful that undercorrection is effective in controlling myopia that is worsening. More recent approaches are to provide lenses that have both a region that provides full correction of visual acuity for distant objects and a region that is undercorrected or intentionally causes defocus due to myopia. Lenses may also be provided that increase the scattering of light in certain regions compared to the light passing through the fully corrected region of the lens. These approaches have been suggested to be able to suppress or slow down the worsening or progression of myopia in children or young people and also provide good distance vision.

[0004] In lenses with a defocusing region, the region that provides complete correction of distance vision is commonly referred to as the base power region, while the region that results in insufficient correction or intentionally causes defocus due to myopia is commonly referred to as the add power region or myopia defocus region (because the power expressed in diopters is somewhat positive (+) or somewhat negative (-) than the power in the distance vision region). The surface of the add power region (typically the anterior surface) has a smaller radius of curvature than the radius of curvature of the distance power region and therefore provides a somewhat positive or somewhat negative power to the eye. The add power region is designed to focus incoming parallel light rays (i.e., light from a distance) in front of the retina (i.e., located near the lens) within the eye, while the distance power region is designed to focus light and form an image on the retina (i.e., located far from the lens).

[0005] In the case of a lens that increases light scattering in a specific region, the scattering-enhancing features may be incorporated into the lens surface or into the material used to form the lens. For example, scattering elements may be baked into the lens.

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

[0007] While these lenses have been found beneficial in preventing or slowing the worsening or progression of myopia, the annular add-on area can produce undesirable visual side effects. Light focused by the annular add-on area in front of the retina diverges from the focal point, forming a defocused annular area on the retina. Therefore, wearers of these lenses may see a ring or "halo" surrounding the image formed on the retina, especially for small luminous objects such as streetlights or car headlights. Also, theoretically, instead of using the eye's innate accommodative ability (i.e., the eye's innate ability to change its focal length) to focus on near objects, wearers may utilize the additional focal point in front of the retina caused by the annular add-on area for focusing on near objects; in other words, wearers may inadvertently use the lenses in the same way as presbyopia-correcting lenses, which is undesirable for young subjects.

[0008] Another lens has been developed that can be used in the treatment of myopia, and such lenses are designed to eliminate the halo observed around the focused distance image in the aforementioned MISIGHT (CooperVision, Inc.) lens and other similar lenses. In these lenses, the annular region is configured so that no single axial image is produced in front of the retina, thereby preventing such an image from being used to avoid the eye having to correspond to a near target. In contrast, a distant point light source is imaged by the annular region into a ring-shaped focal line at the near add power focal plane, thereby producing a small spot-sized light without producing the peripheral "halo" effect on the retina at the distance focal plane. [Overview of the project] [Problems that the invention aims to solve]

[0009] It has been recognized that the eye may adapt over time to compensate for defocusing due to myopia and light scattering characteristics incorporated into the lens. This may reduce the effectiveness of lenses intended to slow the progression of myopia. This disclosure aims to address this issue and provide a pair of lenses usable in young subjects that can suppress or slow the progression of myopia.

[0010] According to a first aspect, the present invention provides a set of contact lenses used to suppress or slow the progression or exacerbation of myopia, wherein each contact lens in the set has an optical zone and a peripheral zone surrounding the optical zone. The peripheral zone of each contact lens has a gradually changing thickness profile configured to control the rotation of the contact lens. The optical zone of each contact lens has a central region. The central region has curvature that provides a first optical axis and base power. The optical zone of each contact lens has an annular region, which surrounds the central region circumferentially, and the annular region has a treatment zone, which has the property of reducing the contrast of the image made by light passing through the central region and the treatment zone compared to the image of an object made by light passing through only the central region. The treatment zone is rotationally positioned at different angles around the optical axis of each contact lens in the set with respect to the peripheral zone thickness profile.

[0011] According to a second aspect of the present invention, the present invention provides a kit used to suppress or slow the progression or worsening of myopia. The kit includes a pair of contact lenses according to the first aspect of the present invention, packaging material for supplying the pair of contact lenses to a user, and instructions for putting on the contact lenses.

[0012] According to a third aspect, the present invention provides a method for manufacturing a pair of contact lenses. The method includes the step of forming a first contact lens, the contact lens having an optical zone and a peripheral zone surrounding the optical zone. The peripheral zone of each contact lens has a gradually changing thickness profile configured to control the rotation of the contact lens. The optical zone of each contact lens has a central region, the central region having curvature that provides a first optical axis and base power. The optical zone of each contact lens has an annular region, the annular region surrounding the central region circumferentially, and the annular region has a treatment zone, the treatment zone having the property of reducing the contrast of the image made by light passing through the central region and the treatment zone compared to the image of an object made by light passing through only the central region. The method includes the step of forming a second contact lens by repeating the above steps. The treatment zone is rotationally positioned at different angles around the optical axes of the first and second contact lenses with respect to the peripheral zone thickness profile.

[0013] According to a fourth aspect of the present invention, the present invention provides a method for reducing the progression of myopia. The method includes providing a person with myopia with a pair of contact lenses according to the first aspect of the present invention that can be adjusted for various near viewing distances.

[0014] Naturally, it will be understood that features described in relation to one aspect of the present invention can be incorporated into other aspects of the present invention. For example, the method of the present invention may include features described in relation to the apparatus of the present invention, and vice versa. [Brief explanation of the drawing]

[0015] [Figure 1] This schematic graph shows the decrease in the modulation transfer function (MTF) with respect to spatial frequency for both aberration-free lenses without an add power region and lenses that include an annular add power region. [Figure 2]This is a schematic diagram showing the field of vision of the eye, divided into four quarters. [Figures 3(a)-3(c)] This is a schematic diagram illustrating the effect of parallax between the lens and the wearer's pupil. [Figure 4] This is a schematic plan view of a pair of lenses as one embodiment of the present invention, showing that each lens has a treatment zone that occupies approximately 50% of the area of ​​the annular region. [Figure 5] This is a cross-sectional view of one of the lenses in Figure 4. [Figure 6] This is a schematic plan view of a set of seven lenses as one embodiment of the present invention, showing that each lens has a treatment zone extending approximately 50° around an annular region. [Figure 7] This is a schematic plan view of a pair of lenses as one embodiment of the present invention, in which each lens has two treatment zones, each treatment zone extends to one quarter of the lens, and each treatment zone has a curvature that results in an add power. [Figure 8] This is a schematic cross-sectional view of the optical zone of the first lens in the lens assembly shown in Figure 7, taken along the line A-A. [Figure 9] This is a schematic cross-sectional view of the optical zone of the first lens in the lens assembly shown in Figure 7, taken along the line B-B. [Figure 10] This is a schematic plan view of a set of four lenses as one embodiment of the present invention, in which each lens has a treatment zone that spans one quarter of the lens, and the treatment zone has a curvature that provides the add power in an asymmetric power profile. [Figure 11] Figures (a) to (d) show the asymmetric frequency profiles as functions of θ for the annular regions of the four lenses in the lens assembly shown in Figure 10. [Figure 12] This is a schematic plan view of a set of four lenses as one embodiment of the present invention, in which each lens has a treatment zone extending over one quarter of the lens, and each treatment zone has the characteristic of increasing the scattering of light that passes through this region. [Modes for carrying out the invention]

[0016] According to a first aspect, the present invention provides a set of contact lenses used to suppress or slow the progression or exacerbation of myopia, wherein each contact lens in the set has an optical zone and a peripheral zone surrounding the optical zone. The peripheral zone of each contact lens has a gradually changing thickness profile configured to control the rotation of the contact lens. The optical zone of each contact lens has a central region. The central region has curvature that provides a first optical axis and base power. The optical zone of each contact lens has an annular region, which surrounds the central region circumferentially, and the annular region has a treatment zone, which has the property of reducing the contrast of the image made by light passing through the central region and the treatment zone compared to the image of an object made by light passing through only the central region. The treatment zone is rotationally positioned at different angles around the optical axis of each contact lens in the set with respect to the peripheral zone thickness profile.

[0017] As used herein, the term "contact lens" refers to an occulmic lens that can be placed on the anterior surface of the eye. As should be understood, such a contact lens provides clinically acceptable inocular movement and does not become fixed to one or both of a person's eyes. The contact lens is preferably in the form of a corneal lens (e.g., a lens that rests on the cornea of ​​the eye). The contact lens is preferably a soft contact lens, such as a hydrogel contact lens or a silicone hydrogel contact lens.

[0018] The contact lens of the present invention has an optical zone. The optical zone includes a portion of the lens having optical functionality. The optical zone is configured to be positioned over the pupil of the eye during use. With respect to the contact lens of the present invention, the optical zone has a central region and an annular region that surrounds the central region and includes a treatment zone. In the context of the present disclosure, the annular region is a substantially annular region that surrounds the optical zone. This 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 the property of causing a reduction in the contrast of an image formed by light passing through the lens as compared to an image formed by light that has only passed through the central region of the lens. In other words, the treatment zone results in a reduction in the contrast of an image formed by light passing through the lens as compared to an image formed by light passing through the same lens without the treatment zone. The treatment zone may have contrast reduction features provided on the surface of the lens. These features may cause additional scattering of light as compared to light passing through the remainder of the annular region and the central region. Such features may cause the light to diffract into a different state as compared to light passing through the remainder of the annular region and the central region. The treatment zone may have a curvature that refracts light in a different manner than the remainder of the annular region and the central region, thereby causing a reduction in the contrast of an image formed by light passing through the lens.

[0020] The treatment zone should preferably be a continuous zone. The treatment zone may be less than half of the annular region. The treatment zone may extend over less than 1 / 4 of the annular region. The annular region may consist of a plurality of treatment zones. The contrast reduction may vary across the entire treatment zone of each lens. Each lens in the lens assembly may have variations in contrast reduction within the same treatment zone. The boundary between any of the treatment zones and the remaining portion of the annular region may be a sharp boundary or a smooth boundary. A blending zone may be provided at the boundary between each treatment zone and the remaining portion of the annular region. The blending zone preferably has the property of causing a contrast reduction in the image formed by the light passing through the lens as compared to the image formed by the light passing through the central region of the lens. Such properties may vary, and such properties may have their contrast reduction effect disappear as going from the treatment zone towards the annular region. For example, if the treatment zone has a curvature that provides a refractive power, the blending zone between the treatment zone and the remaining portion of the annular region may exhibit a gradual change in curvature, and as a result, a gradual decrease in refractive power may occur across this region. If the treatment zone has a characteristic of increasing light scattering, the blending zone between the treatment zone and the remaining portion of the annular region preferably has a characteristic of increasing scattering, but the density of these characteristics may vary across the entire blending zone.

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

[0022] Lenses cannot perfectly reproduce the contrast of an object in the image they create. The modulation transfer function (MTF) of a given lens measures its ability to transfer contrast from an object to its image at a given resolution, and such a modulation transfer function can be derived from the Fourier transform of the point spread function or line spread function. To measure the MTF, it is best to use a test object (the object being imaged) consisting of pairs of black and white lines. As the spacing between the lines of the test object decreases (i.e., as the pairs of black and white lines get closer to each other, i.e., as the spatial frequency increases), the line spread functions of the black lines begin to overlap, and therefore the difference between the black lines and their background decreases in the image, and the MTF decreases.

[0023] Regarding a lens as an embodiment of the present invention, the presence of a treatment zone reduces the MTF (and therefore contrast) of the image formed by light passing through the treatment zone and the central zone compared to the image formed by light passing through only the central region. This can be clearly seen by referring to Figure 1. As shown by curve A (dashed line), for an aberration-free lens without an add power region, the MTF decreases as a function of spatial frequency. In the case of a lens having an optical zone including an annular region with an add power, additional modulation is introduced into the MTF as shown by curve B.

[0024] Thus, the additional contrast attenuation can be said to be a result of the treatment zone having an add frequency. As a variation, for example, the treatment zone may have features that cause increased light scattering.

[0025] With respect to a lens as an embodiment of the present invention, the contrast attenuation caused by the treatment zone can result in a reduction in contrast between the image formed by light passing through both the treatment zone and the central region and the image formed by light passing through both regions, compared to the image formed by light passing through only the central region.

[0026] The optical zone is surrounded by the peripheral zone. The edge zone should ideally 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. The peripheral zone performs mechanical functions, such as increasing the lens size, thereby making the lens easier to handle, providing ballast stabilization to prevent lens rotation, and / or creating a modified area that enhances comfort for the lens wearer. The peripheral zone should ideally extend to the edge of the contact lens.

[0027] A contact lens according to an embodiment of the present invention exhibits a change in peripheral zone thickness configured to control lens rotation. Each lens in the lens assembly preferably has the same peripheral zone thickness profile. The change in peripheral zone thickness is preferably configured to stabilize the lens in a specific orientation. The change in thickness is preferably a continuously changing thickness around the peripheral zone. The thickness of the peripheral zone preferably increases towards the bottom of the lens (considered to be in its normal orientation when the lens is worn by the wearer). The change in thickness may be caused by the curvature of the front surface of the peripheral zone. The change in thickness may be caused by the curvature of the rear surface of the peripheral zone. The change in thickness may be caused by a combination of the curvatures of the rear and front surfaces of the peripheral zone. The change in peripheral zone thickness is preferably configured to facilitate lens rotation in a specific direction.

[0028] The thickness of various regions of the peripheral zone can be selected using conventional methods known to those skilled in the art. The thickness and shape should be selected to achieve any desired amount of contact lens rotation on the eye without significantly reducing the comfort or feel of the contact lens. For example, with respect to the design of the peripheral zone, the contact lens should be manufactured with a specific target design and thickness and clinically tested on the human eye. 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 comfort level of the lens is significantly lower compared to a control lens, lenses with different thickness profiles in the peripheral zone are manufactured and tested.

[0029] The lens may have one or more stabilizing features. For example, the lens may include a periballast, a prism ballast, or a dynamic stabilizing feature (e.g., two thin zones provided along a vertical meridian separating the upper and lower halves). The periballast may include ballast to orient the lens when it is positioned over the wearer's eye. The ballast may be a prism ballast. Once placed over the wearer's eye, the lens may rotate to a predetermined angle of repose due to the action of the wearer's eyelids and gravity. The ballast may be a wedge, and the rotation may result from the rotational force exerted on the wedge by the wearer's eyelids. The prism ballast may be provided on the front surface of the lens. A contact lens with a prism ballast may have a uniform thickness extending in the form of a horizontal band throughout the entire peripheral zone, in which case the horizontal band gradually increases in thickness from a small thickness in the upper part of the lens to a relatively larger thickness in the lower part of the lens, and then tapers to a thin thickness near the lower edge of the contact lens. As a reference system, the horizontal band is parallel to the horizontal line passing through the center of the contact lens when viewed in a plan view and with the upper part of the lens located at the top of the field of view. 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 within 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, and this thickness may gradually increase toward the 0° / 180° meridian. The stabilization feature has two thin zones, the region of maximum thickness is preferably located near the 0° / 180° meridian and is preferably in the range of 250 to 450 micrometers. If the stabilization feature is a prism ballast, the thickness of the peripheral zone is preferably continuously increasing up to the maximum thickness of the lower part of the peripheral zone, and the maximum thickness is preferably about 250 to 450 micrometers. Rotation is also preferably supported by gravity acting on the lens.Each lens in the lens assembly may exhibit the same change in thickness of its peripheral zone, or each lens in the lens assembly may exhibit a change in thickness of its peripheral zone that produces the same or similar effect when the lens is worn by a wearer. For example, each lens in the lens assembly may exhibit a change in thickness of its peripheral zone, and as a result, the lens rotates so that it is positioned in the same orientation around the first optical axis when the lens is worn by a wearer.

[0030] The contact lens is preferably substantially circular in shape and has a diameter of about 4 mm to about 20 mm, preferably about 13.0 mm to about 15.0 mm. In this specification, when referred to as diameter, this means the chord diameter. The central thickness of the lens is preferably about 50 micrometers to about 300 micrometers. The peripheral zone of the lens is preferably about 50 micrometers to about 450 micrometers thick. The lens thickness is preferably measured using prior art and instruments, such as a radar (Rehder) instrument. The optical zone is preferably substantially circular in shape and has 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 vision of the eye can be divided into quarters, as shown in Figure 2, and these quarters are also useful for describing the quarters 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 vision closest to the nose is the nasal half 5, and the field of vision farther from the nose is the temporal half 7. Thus, the four quarters can be defined as superior-nasal 9, superior-temporal 11, inferior-nasal 13, and inferior-temporal 15. In the following description, these definitions will be used to describe the position of the add power area and the change in the thickness of the peripheral zone when the lens is in normal use and when worn by the wearer.

[0032] In various embodiments of the present invention, with respect to off-axis light incident on the lens, the light is roughly mapped from each quarter of the wearer's field of vision to the opposite quarter of the retina. Parallax occurs as a result of the axial separation between the lens and the wearer's pupil when positioned on the anterior surface of the cornea, causing the relative positions of the lens and the pupil to shift as the visual angle changes or as the direction of light incident on the lens changes. This is illustrated in Figures 3(a) to 3(c) as an example, showing a lens 17 as one embodiment of the present invention, which has a treatment zone 19 extending over approximately half of the annular region (temporal half). The iris 21 is schematically shown as seen through the cornea. As shown in Figure 4(b), the contrast reduction characteristics of the treatment zone 19 affect the light imaged from the wearer's right field of vision, but as shown in Figure 4(c), the contrast reduction characteristics of the treatment zone 19 do not affect the light imaged from the wearer's left field of vision. Light from the wearer's left visual field, after passing through the treatment zone 19, is blocked by the iris 21. With respect to this lens 17, the treatment zone 19 significantly reduces image contrast with respect to the left retina (nasal retina of the right eye, temporal retina of the left eye), but not with respect to the right retina (temporal retina of the right eye, nasal retina of the left eye). If the treatment zone extends to the nasal half of the lens instead of the temporal half, it is clear that the lens significantly reduces image contrast with respect to the right (temporal) retina, but not with respect to the left (nasal) retina. By placing the treatment zone 17 within the annular region of the lens, contrast attenuation can be targeted in the peripheral retinal zone while minimizing interference with foveal vision.

[0033] For each lens in the lens assembly, the change in thickness of the peripheral zone is preferably symmetrical with respect to the lens diameter line, in which case the lens diameter line divides the annular region into two halves, and the treatment zone is limited to one half of the annular region. The change in thickness is preferably substantially limited to be located along the lens diameter line. Using the change in thickness of the peripheral zone, the position of the treatment zone relative to the wearer's retina can be controlled when the lens is worn by the wearer.

[0034] The change in thickness of the peripheral zone may include ballast, which can control the rotation of the lens. When the lens is in use, it is preferable that the lens rotates so that the ballast is located at or near the bottom of the lens, i.e., within the lower half. The lens rotates so that the ballast is symmetrical with respect to the line dividing the lens into the temporal and nasal halves.

[0035] The lens diameter should ideally be positioned along the line separating the nasal and temporal halves of the lens.

[0036] With respect to each lens in the lens assembly, the contrast reduction change portion of the treatment zone is rotationally positioned at different angles around the optical axis of each lens in the lens assembly with respect to the thickness profile of the peripheral zone. For example, each lens in the lens assembly may have a treatment zone that occupies approximately 25% of the area of ​​the annular region. The first lens in the lens assembly may have a treatment zone extending from the lower to the temporal quarter of the lens, the second lens may have a treatment zone extending from the upper to the temporal quarter of the lens, the third lens may have a treatment zone extending from the upper to the nasal quarter of the lens, and the fourth lens may have a treatment zone extending from the lower to the nasal quarter of the lens.

[0037] A lens kit may consist of, for example, two lenses, which are intended to be worn in rotation over several days. Alternatively, a lens kit may consist of, for example, seven lenses, which are intended to be worn in rotation on a daily basis.

[0038] Each lens in the lens set has a treatment zone that is rotationally positioned at a different angle around the optical axis relative to the thickness profile of the peripheral zone. Therefore, when each lens in the lens set is worn by the wearer, the treatment zones target different areas of the retina. Consequently, wearing each lens in the lens set consecutively may reduce the eye's ability to compensate for the contrast-reducing effect of the treatment zones.

[0039] The first optical axis of the central region is preferably located along the center line of the lens. The central region can focus light from a distant point object on the first optical axis onto a spot on the first optical axis at the far focal plane. As used herein, the term surface does not mean a physical surface, but rather a surface that can be drawn through the point where light from a distant object is focused. Such a surface is also called the image plane (even if it is a curved surface) or image shell. The eye focuses light onto the 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 commonly referred to locally as a plane.

[0040] In some embodiments, the treatment zone may be provided over a continuous 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 some embodiments, multiple unbonded treatment zones may be positioned across the annular region of each lens.

[0041] In embodiments where each lens has multiple unbonded treatment zones, the total area occupied by the unbonded treatment zones of each lens is preferably less than 50% of the area of ​​the annular region. The total area occupied by the unbonded treatment zones of each lens is preferably less than 25% of the area of ​​the annular region. The total area occupied by the unbonded treatment zones of each lens is preferably less than 10% of the area of ​​the annular region. Each unbonded treatment zone is preferably located over 5-10% of the perimeter of the annular region. With respect to each lens, each unbonded treatment zone is preferably of approximately the same area. With respect to each lens, the unbonded treatment zones may be arranged at regular intervals along the perimeter of the annular region, or they may be arranged at irregular intervals along the perimeter of the annular region. The unbonded portions are preferably separated by portions of the annular region that do not substantially reduce the contrast of the image of an object formed by light passing through the central region and the treatment zones compared to the image of an object formed by light passing through only the central region. The portions between treatment zones should have a curvature that provides the base degree.

[0042] The treatment zone of each lens in the lens assembly preferably has a strong contrast reduction region that reduces the contrast of the image of an object formed by light passing through both the central region and the treatment zone by 50% or more compared to the image of an object formed by light passing through only the central region. The strong contrast reduction region preferably reduces the contrast of the image formed by the lens by 75% or more. The treatment zone preferably further has a weak contrast reduction region that reduces the contrast of the image of an object formed by light passing through both the central region and the treatment zone by less than 50% compared to the image of an object formed by light passing through only the central region. In embodiments in which each lens in the lens assembly 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 should exhibit a change in curvature that results in the added power.

[0044] The front surface of the treatment zone should have a smaller radius of curvature than the front surface of the central and remaining parts of the annular region. Therefore, the treatment zone can have a greater power than the base power of the central and remaining parts of the annular region. The focal point of the treatment zone should be located on the near focal plane, while the focal points of the central and remaining parts of the annular region should be located on the far focal plane, which is farther away from the rear surface of the lens. The focal points of the treatment zone and the central region should share a common optical axis. In the case of a point light source located at infinity, the rays focused by the central and annular regions create a focused image at the far focal plane. The rays focused by the central region also produce a blurred, out-of-focus spot at the near focal plane.

[0045] For each lens, at least a certain percentage of the added power is preferably provided by a curvature located on a center of curvature whose center is at a first distance from the first optical axis.

[0046] Rays from a distant point light source passing through the treatment zone should ideally be focused on the add power focal plane, moving away from the first optical axis. Rays passing through the central region can form a blurred circle (or ellipse in the case of toric lenses) on the axis at the maximum add power focal plane. Rays from a distant point light source passing through the treatment zone should ideally 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 should ideally be located at a first distance from the first optical axis.

[0047] At least one add power region is preferably configured to produce a light distribution at the focal plane of the add power region that reproduces any zone geometric shape of the add power region as a whole. The focal plane of the add power region is determined by a plane that passes through the point where light passing through the add power region focuses. With respect to an add power region spanning a portion of an annular region, a focusing arc can be produced at the focal plane of the add power region. The curvature of the treatment zone or portion is preferably selected to position the light focused at the treatment zone focal plane at a distance of about 2 to 700 micrometers, preferably about 20 to 300 micrometers, from and perpendicular to the optical axis.

[0048] The treatment zone of the annular region has a width, and a perpendicular line taken at half the width of the treatment zone's surface intersects a perpendicular line taken at the center of curvature of the central region's surface. This allows the treatment zone to focus light from each far-point object, creating a focused arc at the near-focal plane, the arc located outside and enclosing the blurred circle created by the light focused by the central region. The surface of the treatment zone is preferably a front surface. The surface of the central region is preferably a front surface. The surface of the treatment zone is preferably a surface with curvature that yields the add frequency. The surface of the central region is preferably a surface with curvature that yields the base frequency.

[0049] The base power of the lens is preferably positive, and the treatment zone should have a power greater than the base power. In this case, the focal plane of the maximum add power is located closer to the lens than the distance focal plane. The on-axial image is not formed by light passing through the treatment zone. Therefore, the lens wearer must use their natural accommodative power to focus on nearby objects. Presumably, the rays focused by the treatment zone do not intersect the first optical axis of the contact lens at all, or do not intersect until after such rays have passed through the add power focal plane.

[0050] The base power of the lens is preferably negative, and the treatment zone is preferably less negative than the base power, or the treatment zone may have a positive power. When the lens is 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 distance focal plane. When the lens is not 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 distance focal plane (which is the virtual focal plane on the object side of the lens for a 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 further away from the lens than the virtual distance focal plane.

[0051] Because each lens in a lens set has an add power in its treatment zone, which 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 its add power to different areas of the retina. Therefore, if the lenses are worn by the wearer at different times, the add power will be directed to different areas of the retina at different times. This is particularly beneficial for hydrogel and silicone hydrogel lenses, as it is thought that over time the eye may adapt to the blurring at the focal plane of the add power, thereby reducing the effectiveness of the add power treatment zone in preventing myopia from worsening. By wearing separate lenses from a lens set consecutively, thereby providing add powers targeted to different areas of the retina at different times, the lenses may reduce the eye's ability to compensate for blurring over time. When different lenses within a set are worn, different parts of the retina are affected by varying amounts of defocus, which may be more effective in slowing the progression of myopia than wearing a single lens that provides consistent myopia defocus.

[0052] In an embodiment in which each lens in a lens assembly 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 different add powers.

[0053] The treatment zone of each lens may have an asymmetrical power profile. For each lens in the lens set, the curvature that provides the add power may be the curvature of the front surface of the lens. For each lens, the curvature that provides the add power may be the curvature of the rear surface of the lens. For each lens, the curvature that provides the add power may be the curvature of the front and rear surfaces of the lens that provide a combined effect.

[0054] Regarding 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 is preferably 0.5 diopters (D) to -20.0 diopters. The base power is preferably -0.25 diopters to -20.0 diopters. The add power is defined as the difference between the base power and the power at the peak of the add power. For each lens in a lens set, the add power provided by each treatment zone is preferably +0.5 to +10.0 D, and more preferably +2.0 to +3.0 D. For lenses with a positive base power, each power in any add power range has a positive value greater than or similar to the base power. For lenses with a negative base power, each power in any add power range may have a negative value less than the base power, or the power in any add power range may be a positive power. The net frequency of the ring region in any given add frequency range is the sum of the base frequency and the add frequency.

[0055] The treatment zone of each lens may include a feature that increases the scattering of light that passes through the treatment zone compared to light that passes through only the central region. Such a feature may be located on the anterior surface of the annular region. The treatment zone of each lens may have an optical element that is baked into or etched onto the surface of the lens. The feature that increases the scattering of light that passes through the treatment zone reduces the contrast of the image formed by light passing through both the treatment zone and the central region compared to the image formed by light that passes through only the central region. When different lenses in a set are worn by the wearer, the highly scattering regions direct light to 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 preferably has a curvature that provides an add degree, in which case the center of the curvature is located on the first optical axis.

[0057] The treatment zone may include properties that cause diffraction of light passing through it. The treatment zone may also include other properties that reduce the contrast of the image formed by light passing through both the treatment zone and the central region compared to the image formed by light passing through only the central region.

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

[0059] The annular region of each lens is preferably in contact with the central region. A hybrid zone is preferably provided between the central region and the annular region. The hybrid zone should not substantially affect the optical properties provided by the central region and the annular region, and the hybrid zone is preferably 0.05 mm or less in radial width, however, in some embodiments, the hybrid zone may have a wider width of 0.2 mm or 0.5 mm.

[0060] The annular region should extend radially outward so as to abut the surrounding zone. The treatment zone should extend across the radial width of the annular region.

[0061] Each lens in the lens assembly preferably has multiple concentric annular regions. Each annular region preferably includes a treatment zone having the characteristics described above.

[0062] The central region of each lens has a base power, which in the context of this 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 be the same value). Thus, the lens powers given herein are nominal powers. These values ​​may differ from lens power values ​​obtained by direct measurement of the lens, which reflect the lens powers used to provide the prescription power required when used in ophthalmic treatment.

[0063] Each lens may be made of an elastomer material, a silicone elastomer 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 in equilibrium and is free of silicone-containing chemicals. A silicone hydrogel is a hydrogel that contains silicone-containing chemicals. The hydrogel materials and silicone hydrogel materials described in relation to the present invention have an equilibrium water content (EWC) of at least 10% to about 90% (weight / weight). In some embodiments, the EWC of the hydrogel material or silicone hydrogel material is about 30% to about 70% (weight / weight). To illustrate with comparison, the water content of the silicone elastomer material described in relation to the present invention is about 0% to less than 10% (weight / weight). Typically, the water content of the silicone elastomer material used in the method or apparatus of the present invention is 0.1% to 3% (weight / weight). Examples of suitable lens formulations include formulations with the following US generic names (USANs): metafilcon A, ocufilcon A, ocufilcon B, ocufilcon C, ocufilcon D, omafilcon A, omafilcon B, comfilcon A, enfilcon A, stenfilcon A, fanfilcon A, and etafilcon These include )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, etc.

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

[0066] In a second view, the present invention includes a kit used to suppress or slow the progression or exacerbation of myopia. The kit includes a pair of contact lenses having any of the above-described features. The kit includes packaging material for supplying the pair of contact lenses to a user. The kit includes instructions for putting on the lenses. Each lens in the pair may be individually packaged, for example, in a blister pack. The packaging material may consist of, for example, a strip of blister packets joined together. The pair of lenses may be a set of two lenses that can be used in rotation over several days. The pair of lenses may be a set of seven lenses that can be used in rotation on different days of the week. The instructions may instruct the wearer to wear a different lens daily or after a certain number of hours or days. The instructions may be provided on the packaging material or on the lenses. The kit may further include a second set of lenses having any of the above-described features. Each lens in the first lens assembly has a treatment zone that is rotationally positioned at a first angle around the first optical axis with respect to the thickness profile of the peripheral zone. With respect to each lens in the first lens assembly, the size and orientation are equal to the first optical axis with respect to the thickness profile of the peripheral zone. OppositionPreferably, a second set of contact lenses is provided, each having a treatment zone positioned at a specific angle. The first set of lenses may be a pair for the wearer's left eye, the second set of lenses may be a pair for the wearer's right eye, or the reverse relationship may hold.

[0067] In a third aspect, the present invention provides a method for manufacturing a pair of contact lenses. The method includes the step of forming a first contact lens, the contact lens having an optical zone and a peripheral zone surrounding the optical zone. The peripheral zone of each contact lens has a gradually changing thickness profile configured to control the rotation of the contact lens. The optical zone of each contact lens has a central region, the central region having curvature that provides a first optical axis and base power. The optical zone of each contact lens has an annular region, the annular region surrounding the central region circumferentially, and the annular region has a treatment zone, the treatment zone having the property of reducing the contrast of the image made by light passing through the central region and the treatment zone compared to the image of an object made by light passing through only the central region. The method includes the step of repeating the above steps to form a second contact lens. The treatment zone reduction change portion is rotationally positioned at different angles around the optical axes of the first and second contact lenses with respect to the peripheral zone thickness profile. This method preferably includes the step of repeatedly performing the above steps to form a pair of contact lenses, wherein the treatment zone of the annular region showing a change in contrast is rotationally positioned at different angles around the optical axis of each contact lens pair with respect to the peripheral zone thickness profile.

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

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

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

[0071] Contact lenses are preferably formed using a lathing process. Lenses are preferably formed by a casting process, a rotational molding process, or a lathing process, or a combination thereof. As will be understood by those skilled in the art, casting means forming a lens by placing a lens-forming material between a female mold member having a concave lens-forming surface and a male mold member having a convex lens-forming surface.

[0072] In a fourth aspect of the present invention, a method of using a pair of contact lenses as described herein is also provided. This method may be effective in reducing the progression of refractive errors, for example, in reducing the progression of myopia. When used to reduce the progression of myopia using the lenses of the present invention, the method includes the step of providing the contact lenses to a person whose eyes can accommodate a range of near viewing distances (e.g., from about 15 cm to about 40 cm). Some embodiments of the method include the step of providing the ofsalmic lenses to a person aged about 5 to about 25 years. This provisioning step is preferably performed by an eye care professional, such as an optician or optometrist. In a variation, such provisioning step may be performed by a lens distributor who arranges the delivery of the ofsalmic lenses to the lens wearer.

[0073] Figure 4 shows a pair of contact lenses 200 used to slow the progression of myopia (e.g., to control myopia) according to one embodiment of the present invention. The pair includes two lenses 201a, 201b. Each lens 201a, 201b has an optical zone 202a, 202b that substantially covers the pupil and peripheral zones 204a, 204b that are located above the iris. The peripheral zones 204a, 204b provide mechanical functions, including the function of providing a shaped region that increases the size of the lenses 201a, 201b, thereby making the lenses 201a, 201b easier to handle and improving the comfort of the lens wearer. The peripheral zones 204a, 204b are thicker towards the bottom of the lens to provide ballast 209a, 209b. In the illustrative diagrams shown and described herein, the location of the thickest part of the ballast is indicated by a triangle, but those skilled in the art will understand that the thickness changes can be implemented by different forms of ballast or other thickness changes (see, for example, paragraph

[0027] ). For each lens 201a, 201b in the set, the thickness changes in the peripheral zones 204a, 204b are identical. For both lenses 201a, 201b in this set, the ballasts 209a, 209b are positioned at the bottom of the lens (i.e., the lower half) along the diameter line separating the temporal and nasal halves of the lens 201a, 201b. Ballasts 209a and 209b control the rotation of lenses 201a and 201b, so that when lenses 201a and 201b are worn, they remain in a stable position despite rotational forces caused by the wearer's blinking. Optical zones 202a and 202b provide the optical functionality of lenses 201a and 201b. Each optical zone 202a and 202b has annular regions 203a and 203b and central regions 205a and 205b.Each annular region 203a, 203b has treatment zones 207a, 207b, which reduce the contrast of the image of an object formed by light passing through both the central region 205a, 205b and the treatment zones 207a, 207b compared to the image of an object formed by light passing through only the central region 205a, 205b. With respect to the lenses 201a, 201b in this pair 200, the first lens 201a has a treatment zone 207a extending over the temporal half of the lens 201a, and the second lens 201b has a treatment zone 201b extending over the nasal half of the lens 201a.

[0074] The position of the lens around its periphery can be determined by an angle θ, as shown in Figure 4, where θ ranges from 0° to 360°. For the two lenses 201a and 201b in this set, the treatment zones 207a and 207b are rotationally positioned around the optical axis at various angles relative to the ballasts 209a and 209b. The treatment zone 207a of the first lens 201a extends from approximately 0° to 180°, and the treatment zone 207b of the second lens extends from approximately 180° to 360°. If the wearer alternates between the two lenses 201a and 201b over several days, the treatment zones 207a and 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] With respect to the lens assembly in Figure 4, the treatment zone has a change in curvature that provides the add power. Figure 5 is a cross-sectional view of lens 201a in Figure 4. The front surface of treatment zone 207a has a smaller radius of curvature than the front surface of the central region 205a and the rest of the annular region 203a. Therefore, treatment zone 207a has a greater power than the base power of the central region 205a and the rest of the annular region 203a. The focal point of treatment zone 207a is located on the near focal plane 222 (shown by the dashed line), and the focal points of the central region 205a and the rest of the annular region 203a are located on the far focal plane 224, which is located away from the rear surface of lens 201a. It is preferable that the focal points of treatment zone 207a and the focal point of central region 205a share a common optical axis 218. In the case of a point light source located at infinity, the light rays focused by the central region 205a and the annular region 203a create a focused image at the far focal plane 224. The light rays focused by the central region 205a also produce an out-of-focus, blurred spot at the near focal plane 222.

[0076] Figure 6 shows a set of contact lenses 300 used to slow the progression of myopia (e.g., to control myopia) according to one embodiment of the present invention. The set includes seven lenses 301a to 301g. Similar to Figure 4, each lens 301a to 301g has an optical zone 302a to 302g that almost completely covers the pupil, and peripheral zones 304a to 304g that are located above the iris. The peripheral zones 304a to 304g provide mechanical functions, including the function of providing a modified area that increases the size of the lenses 301a to 301g, thereby making the lenses 301a to 301g easier to handle and improving the comfort of the lens wearer. The peripheral zones 304a to 304g exhibit a change in thickness provided by the ballast 309a to 309g. With respect to each lens 301a to 301g in the set, the change in thickness of the peripheral zones 304a to 304g is identical. For each of the lenses 301a to 301g in this set, the ballasts 309a to 309g are positioned at the bottom of the lens (i.e., the lower half) along the diameter line separating the temporal and nasal halves of the lens 301a to 301g. The ballasts 309a to 309g control the rotation of the lenses 301a to 301g, so that when the lenses 301a to 301g are worn, they remain in a stable position despite the rotational force caused by the wearer's blinking. The optical zones 302a to 302g provide the optical functionality of the lenses 301a to 301g. Each optical zone 302a to 302g has an annular region 303a to 303g and a central region 305a to 305g. Each annular region 303a to 303g has a treatment zone 307a to 307g, and the treatment zones 307a to 307g reduce the contrast of the image of an object created by light that has passed through both the central region 305a to 305g and the treatment zones 307a to 307g, compared to the image of an object created by light that has passed through only the central region 305a to 305g.By defining the position of the lenses 301a to 301g around their periphery by an angle θ (in this case, theta is 0° to 360°), the first lens 301a has a treatment zone 307a extending approximately 0° to 50° along the annular region 303a, and the second lens 301b has a treatment zone 307b extending approximately 50° to 100°. Each lens 301a to 301g in the set has treatment zones 307a to 307g extending over different sectors (fan-shaped portions) of the annular region 303a to 303g relative to the ballast 309a to 309g. If the wearer wears the lenses 301a to 301g in rotation over several days, the treatment zones 307a to 307g will target different areas of the retina at different times.

[0077] Figure 7 shows a pair of contact lenses 400 used to slow the progression of myopia (e.g., to control myopia) according to one embodiment of the present invention. The pair includes two lenses 401a and 401b. Similar to Figure 4, each lens 401a and 401b has an optical zone 402a and 402b that substantially covers the pupil, and peripheral zones 404a and 404b that are located above the iris. The peripheral zones 404a and 404b provide mechanical functions, including the function of providing a modified area that increases the size of the lenses 401a and 401b, thereby making the lenses 401a and 401b easier to handle and improving the comfort of the lens wearer. The peripheral zones 404a and 404b exhibit a change in thickness provided by the ballast 409a and 409b. With respect to each lens 401a and 401b in the pair, the change in thickness of the peripheral zones 404a and 404b is identical. For each of the lenses 401a and 401b in this set, the ballasts 409a and 409b are positioned at the bottom of the lens (i.e., the lower half) along the diameter line separating the temporal and nasal halves of the lens 401a and 401b. The ballasts 409a and 409b control the rotation of the lenses 401a and 401b, so that when the lenses 401a and 401b are worn, they remain in a stable position despite the rotational forces caused by the wearer's blinking. The optical zones 402a and 402b provide the optical functionality of the lenses 401a and 401b. Each optical zone 402a and 402b has an annular region 403a and 403b and a central region 405a and 405b. Each annular region 403a, 403b has two treatment zones 407a, 407b, 407a′, 407b′, and the treatment zones 407a, 407b, 407a′, 407b′ reduce the contrast of the image of an object created by light that has passed through the central region 405a, 405b and the treatment zones 407a, 407b, 407a′, 407b′ compared to the image of an object created by light that has passed through only the central region 405a, 405b.By defining the positions of the lenses 401a and 401b around their periphery by an angle θ (in this case, theta is 0° to 360°), the first lens 401a has a first treatment zone 407a extending from the superior-temporal quarter along the annular region 403a, or from 270° to 360°, and a second treatment zone 407a' extending from the inferior-nasal quarter along the annular region 403a, or from 90° to 180°. The second lens 401b has a first treatment zone 407b extending from the superior-nasal quarter along the annular region 403b, or from 0° to 90°, and a second treatment zone 407b' extending from the inferior-temporal quarter along the annular region 403b, or from 180° to 270°.

[0078] Each lens 401a, 401b in the set 400 has two treatment zones 407a, 407b, 407a′, 407b′, and the treatment zone of each lens spans different sectors (fan-shaped portions) of the annular region 403a, 403b relative to the ballast 409a, 409b. If the wearer wears lenses 401a, 401b in rotation over several days, the treatment zones 407a, 407b, 407a′, 407b′ will target different areas of the retina at different times.

[0079] With respect to lenses 401a and 401b in Figure 7, each treatment zone 407a, 407b, 407a′, and 407b′ has a curvature that provides the add power. With respect to each lens, the central regions 405a and 405b provide the base power and have a curvature centered on a curvature center located on the first optical axis 418. This is shown in Figure 8, which is a schematic cross-sectional view of the first lens 407a in the set along the line A-A.

[0080] Each treatment zone 407a, 407a' has a curvature that provides an add power. The radius of curvature 406a of the front surface of treatment zones 407a, 407a' (indicated by dashed circles) is smaller than the radius of curvature 410 of the front surface of the central region 405a (indicated by a dashed circle). Therefore, treatment zones 407a, 407a' have a power greater than the base power of the central region 405. Each of treatment zones 407a, 407a' has the same front curvature and the same power. As shown in Figure 8, the focal points of 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 far from the rear surface of lens 401a. The focal points 425 of treatment zones 407a and 407a' and the focal point 424 of central region 405a share a common optical axis 418. With respect to a point light source at infinity, rays focused by central region 405a create a focused image at the far focal plane 424. Rays focused by central region 405a also produce an out-of-focus, blurred spot at the near focal plane 422. Rays focused by treatment zones 407a and 407a' create a focused image at the near focal plane 422. Rays 420 focused by treatment zones 407a and 407a' diverge after the near focal plane 422.

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

[0082] The second lens 401b in the pair 400 has treatment zones 407b and 407b' that extend to opposite quarters. Therefore, if the wearer alternates between the two lenses 401a and 401a' over two days, on the first day, the treatment zones 407a and 407a' of the first lens 401a will target the add power to the first two quarters (in this case, the inferior-nasal and superior-temporal quarters), and on the next day, the treatment zones 407b and 407b' of the second lens 401b will target the add power to the next two different quarters (in this case, the inferior-temporal and superior-nasal quarters).

[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] Figure 10 shows a pair of contact lenses 500 used to slow the progression of myopia (e.g., to control myopia) according to one embodiment of the present invention. The pair 500 includes four lenses 501a to 501d. Each lens 501a to 501d has an optical zone 502a to 502d that substantially covers the pupil, and peripheral zones 504a to 504d that are located above the iris. The peripheral zones 504a to 504d provide mechanical functions, including the function of providing a modified area that increases the size of the lenses 501a to 501d, thereby making the lenses 501a to 501d easier to handle and improving the comfort of the lens wearer. The peripheral zones 504a to 504d exhibit a change in thickness provided by ballast 509a to 509d. With respect to each lens 501a to 501d in the pair, the change in thickness of the peripheral zones 504a to 504d is identical. For each of the lenses 501a to 501d in this set, the ballasts 509a to 509d are positioned at the bottom (i.e., the lower half) of the lenses 501a to 501d, along the diameter line separating the temporal and nasal halves of the lenses 501a to 501d. The ballasts 509a to 509d control the rotation of the lenses 501a to 501d, so that when the lenses 501a to 501d are worn, they remain in a stable position despite the rotational forces caused by the wearer's blinking. The optical zones 502a to 502d provide the optical functionality of the lenses 501a to 501d. Each optical zone 502a to 502d has an annular region 503a to 503d and a central region 505a to 505d. Each annular region 503a to 503d has a treatment zone 507a to 507d, and the treatment zones 507a to 507d reduce the contrast of the image of an object formed by light that has passed through both the central region 505a to 505d and the treatment zones 507a to 507d, compared to the image of an object formed by light that has passed through only the central region 505a to 505d. The contrast reduction changes along the meridians around the annular regions 503a to 503d.By defining the position of the lenses 501a to 501d around the periphery by an angle θ (in this case, theta is 0° to 360°), the first lens 501a has a first treatment zone 507a extending from the superior-temporal quarter along the annular region 503a, or from 270° to 360°; the second lens 501b has a second treatment zone 507b extending from the superior-nasal quarter along the annular region 503b, or from 0° to 90°; the third lens 501c has a treatment zone 507c extending from the inferior-nasal quarter along the annular region 503c, or from 90° to 180°; and the fourth lens 501d has a treatment zone 507d extending from the inferior-temporal quarter along the annular region 503d, or from 180° to 270°.

[0085] Therefore, each lens 501a to 501d in the set has treatment zones 507a to 507d that span different segments of the annular region 503a to 503d relative to the ballast 509a to 509d. If the wearer wears lenses 501a to 501d in rotation over several days, the treatment zones 507a to 507d will target different areas of the retina.

[0086] With respect to lenses 501a to 501d in Figure 10, each treatment zone 507a to 507d has a curvature that provides the add power. With respect to each lens, the central region 505 provides the base power and has a curvature whose center is the center of curvature 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 front surface of treatment zones 507a–507d is smaller than the radius of curvature of the front surface of the central region 505a–505d. Therefore, treatment zones 507a–507d have a power greater than the base power of the central region 505a–505d. Each of treatment zones 507a–507d has the same front curvature and the same power, and each of the treatment zones has an asymmetric front surface curvature, thereby resulting in an asymmetric power profile. Exemplary asymmetric power profiles are shown for each lens in set 500 in Figures 11(a)–11(d). With respect to each lens 501a–501d, treatment zones 507b–507d are rotated 90° around the annular region 503(a)–503(d).

[0088] Figure 12 shows a pair of contact lenses 600 used to slow the progression of myopia (e.g., to control myopia) according to one embodiment of the present invention. This pair 600 is similar to the pair of lenses shown in Figure 10. However, with respect to this pair of lenses 601a to 601d, each of the treatment zones 607a to 607d has a feature 608a to 608d that increases the scattering of light passing through the treatment zones 607a to 607d compared to the light passing through the rest of the annular regions 603a to 603d and the central regions 605a to 605d. This reduces the contrast of the image of the object, thereby reducing the contrast of the image made by light passing through the central regions 605a to 605d and the treatment zones 607a to 607d compared to the image made by light passing through only the central regions 605a to 605d. If the wearer wears lenses 601a to 601d in sequence, treatment zones 607a to 607d target different areas of the retina, which may reduce the eye's ability to compensate for the contrast-reducing effect of the treatment zones.

[0089] In the embodiment shown in Figure 12, the light scattering feature is provided in a treatment zone extending to a single quarter of the annular region of each lens. As understood, such feature may be provided in lenses having any other form of treatment zone that falls within the scope of the present invention as described in the claims.

[0090] In other embodiments (not shown), each lens in the lens assembly may have two concentric annular regions, and each annular region may be an annular region including a treatment zone, as described above.

[0091] In other embodiments, the treatment zone may have the property of reducing the light contrast of the image formed by light passing through both the central region and the treatment zone, compared to the image formed by light passing through only the central region, by causing a diffraction effect.

[0092] To make it clear, a wearer can be provided with one pair of lenses for the right eye and one pair of lenses for the left eye. Given a pair of lenses (right eye lens and left eye lens) that can be worn for a given day, both lenses may have a treatment zone that extends over the same half or quarter of the annular region. For example, both lenses may have a treatment zone that extends to the temporal half of the lens and targets the nasal retina. The treatment zone of the right eye lens produces a strong contrast reduction effect on the left retina of the right eye. The treatment zone of the left eye lens produces a strong contrast reduction effect on the right retina of the left eye. Correspondingly, the right eye lens produces a weak contrast reduction effect on the right retina of the right eye, and the left eye lens produces a weak contrast reduction effect on the left retina of the left eye. The brain receives signals from both eyes and both areas of the retinas, but the image with weakly reduced contrast occupies the main portion of the binocular image in the cerebral cortex. Therefore, at the perceptual level, image degradation can be avoided during normal binocular vision.

[0093] In the above description, integers or elements having known, obvious, or predictable equivalents are referred to herein as if they were described individually. Refer to the claims that define the true scope of the invention, which should be considered to include any such equivalent. Furthermore, as the reader will understand, integers or features described in this disclosure as advantageous, favorable, etc., are optional and do not limit the scope of the independent claims. Moreover, it should be understood that while some embodiments of the invention may be beneficial, such optional integers or features may not be desirable and therefore may not be described in other embodiments.

Claims

1. A kit used to suppress or slow the progression or worsening of myopia, the kit is A first set of multiple contact lenses is included, each contact lens in the first set of multiple contact lenses has an optical zone and a peripheral zone surrounding the optical zone, the peripheral zone of each contact lens has a gradually changing thickness profile configured to control the rotation of the multiple contact lenses, and the optical zone of each contact lens is Having a central region, the central region having a curvature that provides a first optical axis and base power, the first optical axis being located along the central axis of the plurality of contact lenses, and the central region having a focal point located on the first optical axis in the far focal plane, Having an annular region, the annular region circumferentially surrounds the central region, the annular region has a treatment zone, the treatment zone has the property of reducing the contrast of the image formed by light passing through the central region and the treatment zone compared to the image of an object formed by light passing through only the central region, the treatment zone of each contact lens has an add power region with curvature that provides an add power, light from each distant point object is focused by the treatment zone to form a focusing arc at the near focal plane, the near focal plane is located closer to the rear surface of the plurality of contact lenses than the far focal plane, the focusing arc is located outside and surrounds the blurred circle formed by the light focused by the central region, A kit comprising a second set of contact lenses having the characteristics of the first set of contact lenses, each contact lens in the first set having a treatment zone rotated at a first angle around the first optical axis with respect to the thickness profile of the peripheral zone, wherein a corresponding contact lens in the second set of contact lenses is provided, having a treatment zone that is equal in size and positioned at the opposite angle around the first optical axis with respect to the thickness profile of the peripheral zone, 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.

2. The kit according to claim 1, wherein the treatment zone of each contact lens is provided on a continuous portion of the annular region of each contact lens, and the treatment zone occupies 50% or less of the area of ​​the annular region of each contact lens.

3. The kit according to claim 1, wherein multiple unbound treatment zones occupy the area of ​​the annular region of each contact lens.

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

5. The kit according to claim 4, wherein the treatment zone of each contact lens has an asymmetrical power profile with respect to the first optical axis.

6. The kit according to claim 4, wherein, with respect to each contact lens, the curvature that yields the added power is the curvature of the front surface of the plurality of contact lenses.

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

8. The kit according to claim 1, wherein the treatment zone of each contact lens includes a scattering feature that increases the scattering of light that has passed through the treatment zone compared to light that has passed through only the central region, and the scattering feature includes or is provided on the front surface of the annular region.

9. The kit according to claim 1, wherein the annular region of each contact lens has a circular outer circumference.

10. The kit according to claim 1, wherein the annular region of each contact lens has an elliptical outer circumference.

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

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

13. The kit according to claim 1, wherein each contact lens comprises an elastomer material, a silicone elastomer material, a hydrogel material, or a silicone hydrogel material, or a mixture thereof.

14. The kit according to claim 1, wherein the gradual thickness profile of each peripheral zone is a prism ballast.

15. A packaging material for supplying the aforementioned set of multiple contact lenses to the user, The kit according to claim 1, further comprising an instruction manual providing instructions for the procedure for wearing the plurality of contact lenses.

16. The instruction manual is provided on the packaging material or on the plurality of contact lenses, according to claim 15.

17. A method for manufacturing a plurality of contact lenses forming a first set and a plurality of contact lenses forming a second set used in the kit described in claim 1, wherein the method comprises: (a) The step of forming a first contact lens for a plurality of contact lenses forming the first set, wherein the plurality of contact lenses have an optical zone and a peripheral zone surrounding the optical zone, the peripheral zone of each contact lens has a gradually changing thickness profile configured to control the rotation of the plurality of contact lenses, and the optical zone of each contact lens is Having a central region, the central region having a curvature that provides a first optical axis and base power, the first optical axis being located along the central axis of the plurality of contact lenses, and the central region having a focal point located on the first optical axis in the far focal plane, Having an annular region, the annular region circumferentially surrounds the central region, the annular region has a treatment zone, the treatment zone has the property of reducing the contrast of the image formed by light passing through the central region and the treatment zone compared to the image of an object formed by light passing through only the central region, the treatment zone of each contact lens has an add power region with curvature that provides an add power, light from each distant point object is focused by the treatment zone to form a focusing arc at the near focal plane, the near focal plane is located closer to the rear surface of the plurality of contact lenses than the far focal plane, the focusing arc is located outside and surrounds the blurred circle formed by the light focused by the central region, (b) a step of repeating step (a) to form a second contact lens in the first set, wherein the treatment zone is rotationally positioned at different angles with respect to the peripheral zone thickness profile, around the first optical axis of the first and second contact lenses. (c) A step of repeatedly performing step (a) and step (b) to form a second set of contact lenses, wherein the second set of contact lenses has the features of step (a) of the first set of contact lenses and has a treatment zone that is rotationally positioned at a first angle around the first optical axis with respect to the thickness profile of the peripheral zone, wherein each contact lens in the first set of contact lenses is positioned at an angle of equal size and opposite direction with respect to the thickness profile of the peripheral zone with respect to the first optical axis A method comprising a second set of contact lenses corresponding to the plurality of contact lenses having a treatment zone, wherein the plurality of contact lenses forming the first set is a set of plurality of contact lenses for the wearer's left eye, and the plurality of contact lenses forming the second set is a set of plurality of contact lenses for the wearer's right eye, or the plurality of contact lenses forming the first set is a set of plurality of contact lenses for the wearer's right eye, and the plurality of contact lenses forming the second set is a set of plurality of contact lenses for the wearer's left eye.

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