Contact lens and related methods

Abstract

A contact lens (101) having an optical zone (102). The optical zone (102) has a central region (105), and the central region has a center of curvature located on the optical axis (119). The optical zone (102) has a first annular region (103). The first annular region (103) has an off-axis center of curvature located at a first distance from the optical axis (119). The first annular region (103) has a sagittal power profile that increases with an increase in the radial distance from the optical axis (119) at a gradient of 1.0 D / mm to 20.0 D / mm. At a point located midway from end to end of the width of the first annular region (103), the sagittal power matches the average radial sagittal power of the central region (105).

Description

Technical Field

[0001] The present invention relates to contact lenses. In particular, but not limited to, the present invention relates to contact lenses that slow the progression of myopia. The present invention also relates to, but is not limited to, contact lenses that can be used by presbyopic people. The present invention also relates to a method of manufacturing such contact lenses.

[0002] 〔Citation of Related Applications〕 This application claims the benefit of priority under 35 U.S.C. § 119(e) to prior U.S. Provisional Patent Application No. 63 / 354,120, filed on June 22, 2022, which is hereby incorporated by reference in its entirety and made a part of this specification.

Background Art

[0003] Many people, including children and adults, require contact lenses to correct myopia (a condition in which parallel light rays converge in front of the retina), and many adults may require lenses to correct presbyopia (a condition in which the eye's ability to accommodate decreases with age, and thus the eye cannot focus on nearby objects).

[0004] Myopia causes incoming light from distant objects to focus at a location in front of the retina. As a result, the light converges towards a plane located in front of the retina (beyond which the light diverges), and then diverges towards the retina, resulting in a loss of focus when it reaches the retina. Conventional lenses for correcting myopia (e.g., eyeglass lenses or contact lenses) reduce the convergence of incoming light from distant objects (in the case of contact lenses) or cause divergence (in the case of eyeglass lenses), after which the incoming light reaches the eye, and as a result, the position of the focus is shifted onto the retina.

[0005] The aging eye does not effectively change its shape to accommodate nearby objects, and thus, a person with presbyopia cannot focus on nearby objects. Conventional lenses for correcting presbyopia (e.g., spectacle lenses or contact lenses) include bifocal or progressive multifocal lenses that include a region optimized for near vision and a region optimized for far vision. Presbyopia may also be treated using bifocal (two-focus) or progressive (multifocal) lenses, or monovision lenses (where different prescriptions are provided for each eye, with a distance vision lens provided for one eye and a near vision lens provided for the other eye).

[0006] Decades ago, it was suggested that to slow or arrest 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 fully moved onto the retina. However, as an inevitable result of this approach, distance vision is reduced compared to that obtained using lenses that fully correct myopia. Furthermore, it is now thought doubtful that undercorrection is effective in suppressing myopia that is worsening. A more recent approach to correcting myopia is to provide a lens having both one or more regions that provide full correction of distance vision and one or more regions that are undercorrected or intentionally cause defocus due to myopia. This approach has been suggested to be able to suppress or slow the worsening or progression of myopia in children or young people and yet provide a good far vision.

[0007] In the case of a lens having a region that causes defocus, the region that provides full correction of distance vision is commonly referred to as the base power (base power or refractive power) region, and the region that causes undercorrection or intentionally causes defocus due to myopia is commonly referred to as the myopic defocus region or the add power (the power expressed in diopters is such that the positive (+) value is larger or the negative (-) value is smaller than the power of the distance (far vision) region). The surface of the add power region (typically, the anterior surface) has a radius of curvature smaller than that of the distance power region, and thus provides a somewhat plus or somewhat minus power to the eye. The add power region is designed to focus incoming parallel light rays (i.e., light from afar) in front of the retina (i.e., near the lens) inside the eye, while the distance power region is designed to be able to focus light and form an image at the retina (i.e., away from the lens).

[0008] One known form of contact lens that reduces or suppresses the progression of myopia is the dual-focus contact lens marketed under the name MISIGHT (CooperVision, Inc.). This dual-focus lens differs from bifocal or multifocal contact lenses configured to improve the vision of presbyopic individuals in that it has certain optical dimensions that allow a person with accommodative ability to use distance correction (i.e., base power) to see both distant and near objects. The therapeutic zone of the dual-focus lens with add power also produces images that are myopically defocused at both distance and near distances.

[0009] These lenses have been found to be beneficial in suppressing or delaying the progression of myopia, but the annular addition power region may cause undesirable visual side effects. Light focused by the annular addition power region in front of the retina diverges from the focus and forms a defocused annulus on the retina. Thus, wearers of these lenses may see a ring or "halo" surrounding the image formed on the retina, particularly for small, bright objects such as streetlights or car headlights. Also, in theory, instead of using the eye's natural accommodation power (i.e., the eye's natural ability to change the focal length) to focus on nearby objects, the wearer can utilize the additional focus that occurs in front of the retina due to the additional annular addition power region to focus on nearby objects. In other words, the wearer may incidentally use the lens in the same way as when a presbyopia-correcting lens is being used, which is undesirable for younger patients.

[0010] It has been recognized that it may be beneficial to provide a lens that introduces additional myopic defocus to treat myopia. It may be beneficial to provide a lens that causes an expansion of the depth of focus to treat presbyopia. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] The present disclosure provides an improved lens that can be used by younger patients to prevent or reduce the progression of myopia. MEANS FOR SOLVING THE PROBLEMS

[0012] According to a first aspect, the present invention provides a contact lens. The contact lens has an optical zone. The optical zone has a central region, and the central region has a center of curvature located on the optical axis. The optical zone has a first annular region, and the first annular region has an off-axis center of curvature located at a first distance from the optical axis. The first annular region has a radial sagittal power profile that increases with a gradient of about 1.0 diopter (D) / mm to about 20.0 D / mm as the radial distance from the optical axis increases. At a point located halfway from end to end of the radial width of the first annular region, the radial sagittal power is equal to the average radial sagittal power of the central region.

[0013] According to a second aspect, the present disclosure provides a method of manufacturing a contact lens according to the first aspect. The method includes the step of forming a contact lens, the contact lens having a central region with a base power and a first annular region with an off-axis center of curvature located at a first distance from the optical axis. The first annular region has a radial sagittal power profile that increases with a gradient of about 1.0 D / mm to about 20.0 D / mm as the radial distance from the optical axis increases. At a point located halfway from end to end of the radial width of the first annular region, the radial sagittal power is equal to the average radial sagittal power of the central region.

[0014] According to a third aspect, the present disclosure provides a method of suppressing or reducing the progression of myopia. The method includes the step of providing a contact lens according to the first aspect to a myopic person whose eye accommodation can be adjusted according to various near viewing distances.

[0015] It will be appreciated that the features described in connection with one aspect of the present disclosure can be incorporated into other aspects of the present disclosure. For example, the methods of the present disclosure can incorporate the features described with respect to the devices or instruments of the present disclosure, and vice versa.

[0016] Next, exemplary embodiments will be described with reference to the accompanying schematic drawings, which are merely exemplary.

Brief Description of the Drawings

[0017]

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Figure 13B

Embodiments for Carrying Out the Invention

[0018] According to a first aspect, the present disclosure provides a contact lens. The contact lens has an optical zone, the optical zone has a central region, and the central region has a center of curvature located on the optical axis. The optical zone has a first annular region, and the first annular region has an off-axis center of curvature located at a first distance from the optical axis. The first annular region has a radial sagittal power profile that increases with a gradient of about 1.0 diopter (D) / mm to about 20.0 D / mm as the radial distance from the optical axis increases. At a point located midway from end to end of the radial width of the first annular region, the radial sagittal power is equal to the average radial sagittal power of the central region.

[0019] As used herein, the term contact lens (hereinafter sometimes simply referred to as "lens") refers to an ophthalmic lens that can be placed on the front surface of the eye. Such contact lenses are understood to provide clinically acceptable movement on the eye and not to adhere to one or both eyes of a person. The contact lens may be in the form of a corneal lens (e.g., a lens that remains positioned 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.

[0020] The contact lens of the present disclosure has an optical zone. The optical zone includes each part of the lens having an optical function. The optical zone is configured to be worn on the pupil of the eye during use. With respect to the contact lens of the present disclosure, the optical zone has a central region and a first annular region surrounding the central region. The optical zone is surrounded by a peripheral zone. The peripheral zone is located outside the optical zone rather than being part of the optical zone when the lens is worn. The peripheral zone performs mechanical functions, such as increasing the size of the lens, thereby making the lens easier to handle, providing a stabilizing effect to prevent rotation of the lens, and / or providing a shaped region that improves comfort for the lens wearer. The peripheral zone may extend to the edge of the contact lens.

[0021] As an embodiment of the present disclosure, a contact lens preferably has a ballast for orienting the lens when worn on the eye of a wearer. Embodiments of the present disclosure incorporating a ballast into the lens rotate to a predetermined rest angle under the action of the wearer's eyelid when worn on the eye of the wearer. For example, the ballast may be a wedge, and the rotation can occur due to the action of the eyelid on the wedge. In the art, it is well known to stabilize and orient contact lenses. For example, toric contact lenses are stabilized to orient such lenses so that the ortho-cylindrical correction provided by the lens aligns accurately with the astigmatism of the wearer's eye.

[0022] The contact lens preferably has a substantially circular shape and a diameter of about 4 mm to about 20 mm. The optical zone preferably has a substantially circular shape and a diameter of about 2 mm to about 10 mm. In some embodiments, the contact lens has a diameter of 13 mm to 15 mm, and the optical zone has a diameter of 7 mm to 9 mm.

[0023] The optical axis is preferably located along the center line of the lens. The central region can focus light from a distant point object on the optical axis to a spot on the 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 a point that focuses light from a distant object. Such a surface is also referred to as an image plane (even if it may be a curved surface) or an image shell. The eye focuses light onto a curved retina, and in a fully 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, it is common practice to refer to the curved surface of the retina as a plane.

[0024] The central region preferably has a substantially circular shape and a diameter of about 2 mm to 9 mm, more preferably about 2.5 mm to 4 mm. The central region may also have a substantially elliptical shape. The first annular region preferably extends radially outward from around the central region by about 0.1 mm to 4 mm, more preferably about 0.5 mm to 1.5 mm. Thus, the radial width of the first annular region can be said to be about 0.1 mm to about 4 mm, more preferably about 0.5 mm to 1.5 mm. The periphery of the central region preferably defines the boundary between the central region and the first annular region, and thus the first annular region preferably adjacent to the central region.

[0025] The first annular region may abut against the central region. A mixed region may be provided between the first annular region and the central region. The mixed region must not have an adverse effect on the optical system provided by the central region and the annular region. The mixed region preferably has a radial width of 0.005 mm or less, although in some embodiments it may have a width as wide as about 0.2 mm, or about 0.5 mm.

[0026] Light rays from a distant point source passing through the first annular region are preferably focused at a location away from the optical axis on the refractive power focal plane. Light rays passing through the central region create an axially blurred circle at the refractive power focal plane. Light rays from a distant point source passing through the first annular region are preferably focused outside the blurred circle.

[0027] The central region preferably focuses light from a distant point object onto a spot on the first optical axis at the distant focal plane. The first annular region preferably acts, for example, as a light beam stop to limit the off-axis light spread at the distant focal plane, thereby improving the optical contrast of the image produced by the lens.

[0028] In the context of the present disclosure, the refractive power of the central region and the annular region of the lens can be defined as the radial curvature refractive power, the circumferential curvature refractive power, the radial sagittal refractive power, and the circumferential sagittal refractive power.

[0029] Define the curvature degree and the sagittal degree as follows.

[0030] For the wavefront W, at a point located at a radial distance r (pupil radius) from the line perpendicular to the center of the wavefront, W(r) = A·r 2 where, in this equation, A is a function.

[0031] Wavefront curvature or curvature degree P c is a function of the second derivative of the wavefront. Wavefront gradient or degree based on the gradient, or sagittal degree P s is a function of the first derivative of the wavefront and varies with the gradient of the wavefront.

[0032] Curvature degree P c is ∂ 2 w / ∂r 2 and, in the case of a simple spherical lens, ∂(2Ar) / ∂r = 2A. Sagittal degree P s is (1 / r)·(∂W / ∂r) and, in the case of a simple spherical lens, 2Ar / r = 2A. In the case of a simple coaxial lens with a spherical wavefront, assuming paraxial conditions, P c = P s is.

[0033] The radial curvature degree is the curvature degree when viewed in the direction extending radially outward from the optical axis of the lens. The circumferential curvature degree is the curvature degree at a fixed radial coordinate extending around the circumference of the lens.

[0034] The radial sagittal degree is the sagittal degree when viewed in the direction extending radially outward from the optical axis of the lens. The circumferential sagittal degree is the sagittal degree at a fixed radial coordinate extending around the circumference of the lens.

[0035] The central region preferably has a radial curvature power that is the same as the radial sagittal power and a circumferential curvature power that is the same as the circumferential sagittal power. The radial curvature power is preferably the same as the circumferential curvature power. Hereinafter, the radial curvature power of the central region may be referred to as the base curvature power or the base power. The radial sagittal power is preferably the same as the circumferential sagittal power. Hereinafter, the radial sagittal power of the central region may be referred to as the base sagittal power. The base curvature power is preferably equal to the base sagittal power. The nominal power of the central region corresponds to the refractive power indicated on the label of the contact lens provided on the contact lens packaging material (however, in practice, the nominal powers may not have the same value). This is the average sagittal or average curvature power taken over the entire central region.

[0036] Regarding the lens used for the treatment of myopia, the base power is negative or close to zero, and the central region corrects the distance vision. The base curvature power is preferably from 0.5 diopter (D) to -15.0 D. The base curvature power is preferably from -0.25 D to -15.0 D. The central region of the lens preferably has a curvature that provides the base power.

[0037] The first annular region preferably has a curvature that provides a radial curvature addition power.

[0038] In the case of the lens as an embodiment of the present disclosure, the first annular region has a radial curvature power greater than the radial curvature power of the central region. Hereinafter, the difference between the radial curvature powers of the first annular region and the central region may be referred to as the radial curvature addition power or the curvature addition power. The circumferential curvature power of the first annular region is preferably the same as the circumferential curvature power of the central region. The net radial curvature power of the first annular region is the sum of the base radial curvature power and the radial curvature addition power. For example, if the lens has a base radial curvature power of -3.0 D and the first annular region has a radial curvature addition power of +4.0 D, the net radial curvature power of the first annular region will be 1.0 D.

[0039] The base curvature power of the lens is preferably positive, and the first annular region preferably has a curvature addition power greater than the base curvature power and positive. In this case, the addition power focal plane is closer to the lens than the far focal plane. The on-axis image is not formed by light passing through the annular region. Therefore, the wearer of the lens needs to use the innate accommodation power of their eye to focus on nearby objects. Presumably, the light rays focused by the annular region do not intersect the optical axis of the contact lens at all, or intersect only after passing through the addition power focal plane.

[0040] The base curvature power of the lens is preferably negative, and the first annular region preferably has a curvature addition power with a negative value smaller than the power of the base region, or the first annular region preferably has a positive curvature power. Considering a lens located on the retina, when the negative value of the curvature addition power of the first annular region is smaller than the negative value of the base power, the addition power focal plane is more forward in the eye than the far focal plane. Considering a lens that is not located on the retina, when the curvature addition power of the first annular region is positive, the addition power focal plane is located on the opposite side (image side) of the lens from the far focal plane (which is a virtual focal plane on the object side of the lens), that is, when the curvature addition power of the first annular region is negative (however, when the negative value is smaller than the base curvature power), the virtual addition power focal plane will be located farther from the lens than the virtual far focal plane.

[0041] The radial curvature addition power of the first annular region is preferably from +0.0D to +20.0D, and preferably from +2.0D to +10.0D. The curvature addition power of the first annular region preferably has the same value, or preferably has the same power profile along any meridian of the first annular region, that is, the radial curvature addition power is preferably constant in the circumferential direction around the first annular region.

[0042] In the context of the present disclosure, the first annular region is a substantially annular region surrounding the optical zone. The first annular region may be substantially circular or substantially elliptical in shape. The first annular region may completely surround the optical zone. The first annular region may partially surround the optical zone.

[0043] The first annular region of the lens is inclined with respect to the central region. As used herein, the inclination of the first annular region means a radial inclination rather than a lateral inclination. Thus, for example, when viewed in a radial cross-section of the lens, the outer end of the arc defining the front surface of the first annular region may be displaced above or below its position within the corresponding non-inclined annular region. Correspondingly, when viewed in three dimensions, the circumferential boundary of the first annular region (formed by the ends of the radial arcs) may be displaced above or below its position within the corresponding non-inclined annular region. In practice, the inclination may be embodied during the optical design of the front surface of the first annular region of the lens. As a variant, the inclination may be embodied during the optical design of the rear surface of the first annular region of the lens, or may be embodied during the optical design of both the front and rear surfaces of the first annular region of the lens.

[0044] Due to the inclination of the first annular region with respect to the central region, the center of curvature of the first annular region is shifted to a position at a first distance from the optical axis. By tilting the first annular region with respect to the central region, the radial sagittal power of the first annular region is changed (this is because it is a function of the first derivative of the wavefront), but the radial curvature power of the annular region, which is a function of the second derivative of the wavefront, is not changed. As a result of the inclination, the radial sagittal power of the annular region will vary across the entire width of the annular region. As a result of the inclination, the first annular region has a radial sagittal power profile that increases with a gradient of approximately 1.0 D / mm to approximately 20.0 D / mm as the radial distance from the optical axis increases, and the degree of inclination is selected such that at a point located at the midpoint from end to end of the radial width of the first annular region, the radial sagittal power is equal to the average radial sagittal power of the central region. The average radial sagittal power of the central region is preferably determined by taking the average radial sagittal power value along the diameter of the central region. Matching the average radial sagittal power of the central region to the radial sagittal power at a point located at the midpoint from end to end of the radial width of the first annular region can improve the control of spherical aberration. Due to spherical aberration, the average sagittal power across the entire first annular region may vary with the nominal or labeled refractive power of the lens. As a result, the visual quality may deteriorate for wearers of lenses with relatively high nominal powers. By matching the average radial sagittal power of the central region to the radial sagittal power at a point located at the midpoint from end to end of the radial width of the first annular region, the unintentional change in sagittal power caused by spherical aberration can be avoided.

[0045] The inclination of the first annular region gives rise to a radial sagittal power which is a ramp function, and such radial sagittal power starts with a value more negative than the radial sagittal power at the outer edge of the central region and increases as the radial distance from the optical axis of the lens increases. The radial sagittal power profile across the entire first annular region from the inner edge (i.e., the edge closest to the optical axis of the lens) to the outer edge (i.e., the edge closest to the peripheral zone) of the first annular region is preferably defined by a curve or line having a positive gradient of about 1.0 D / mm to about 20.0 D / mm, more preferably about 1.0 D / mm to about 6.0 D / mm. The radial sagittal power profile across the entire first annular region is preferably linear or defined by a curve having an average gradient of about 1.0 D / mm to about 20.0 D / mm, more preferably about 1.0 D / mm to about 6.0 D / mm.

[0046] The first annular region preferably has a radial sagittal power profile that increases with a gradient of about 2.0 D / mm to about 20.0 D / mm, more preferably about 4.0 D / mm to about 12.0 D / mm, as the radial distance from the optical axis increases. As a variant, the first annular region may have a radial sagittal power profile that increases with a gradient of about 1.0 D / mm to about 6.0 D / mm as the radial distance from the optical axis increases. This gradient depends, inter alia, on the radial curvature power of the first annular region. For a given inclination of the first annular region with respect to the central region, the greater the curvature contribution power of the first annular region, the greater the increase in the sagittal power across the entire first annular region.

[0047] The circumferential sagittal power of the first annular region at a point midway from end to end of the width of the annular region is preferably the same as the circumferential sagittal power of the central region. The average circumferential sagittal power of the annular region is preferably the same as the circumferential sagittal power of the central region.

[0048] The radial sagittal power across the entire central region should be approximately constant. The radial curvature power across the entire central region should be approximately constant. The radial curvature power across the entire first annular region should be approximately constant, and this radial curvature power should be greater than the radial curvature power across the entire central region.

[0049] The radial sagittal power at the inner edge of the first annular region (i.e., at the edge closest to the central region) should be 0.1 D to 5.0 D less than the radial sagittal power at the outer edge of the central region. The radial sagittal power at the inner edge of the first annular region (at the edge closest to the central region) is preferably about 0.5 D to 2.5 D less than the radial sagittal power at the outer edge of the central region. The radial sagittal power at the outermost edge of the first annular region (i.e., at the edge closest to the peripheral zone) should be 0.1 D to 5.0 D greater than the radial sagittal power at the outer edge of the central region. The radial sagittal power at the outer edge of the first annular region (i.e., at the edge closest to the peripheral region) is preferably 0.5 D to 2.0 D greater than the radial sagittal power at the outer edge of the central region.

[0050] The lens may have at least one additional annular region concentric with the first annular region. Each of the additional annular regions may be tilted with respect to the central region, and as a result, each of the additional annular regions has an off-axis curvature center located at a second distance from the optical axis. Each of the additional annular regions has a sagittal power profile that increases with a gradient of about 1.0 D / mm to about 20.0 D / mm as the radial distance from the optical axis increases. Each of the additional annular regions preferably has a sagittal power profile that increases with a gradient of about 4.0 D / mm to about 20.0 D / mm as the radial distance from the optical axis increases. As a variant, each of the additional annular regions may have a sagittal power profile that increases with a gradient of about 1.0 D / mm to about 3.5 D / mm as the radial distance from the optical axis increases.

[0051] Each of the additional annular regions preferably has a radial curvature degree greater than that of the central region. Each of the additional annular regions may have the same radial curvature degree as the first annular region, or may have a radial curvature degree different from that of the first annular region.

[0052] At a point located at the midpoint from end to end of the radial width of each of the additional annular regions, the radial sagittal degree of the annular region is preferably equal to the average radial sagittal degree of the central region, which can improve the control of spherical aberration.

[0053] Similar to the first annular region, each of the additional annular regions is inclined with respect to the central region. Each of the additional annular regions may be inclined with respect to the central region by the same amount as the first annular region, or by an amount different from that of the first annular region. By inclining each of the additional annular regions with respect to the central region, the center of curvature of the annular region is shifted away from the optical axis. The center of curvature of each of the additional annular regions is preferably shifted away from the optical axis by the same distance as the center of curvature of the first annular region. As a variant, the center of curvature of each of the additional annular regions may be shifted away from the optical axis by a distance different from that of the center of curvature of the first annular region.

[0054] By inclining each of the additional annular regions with respect to the central region, the radial sagittal degree of the annular region is changed because it is a function of the first derivative of the wavefront. Depending on the inclination, the radial curvature degree of the annular region is not changed because it is a function of the second derivative of the wavefront. As a result of the inclination, each of the additional annular regions may have the same change as the first annular region in the radial sagittal degree, or may have a change different from that of the first annular region in the radial sagittal degree. Each of the additional annular regions preferably has a radial sagittal degree gradient different from that of the first annular region as a result of different inclinations of each annular region with respect to the central region, or as a result of having a different curvature contribution degree compared to the first annular region.

[0055] The radius region sagittal degree profile of each of the additional annular regions may depend on the radial position of the additional annular region. An annular region located at a long radial distance from the optical axis may have a larger radial sagittal degree gradient than the first annular region, or may have a smaller radial sagittal degree gradient than the first annular region. An annular region located at a long radial distance from the optical axis preferably has a smaller radial sagittal degree gradient than the first annular region, because at a long radial distance from the optical axis, a given radial curvature degree can be achieved with a smaller radial sagittal degree gradient. Between each of the first annular region and the additional annular regions, the lens preferably has a radial curvature degree smaller than the radial curvature degree of the first annular region. Hereinafter, the regions of the lens between the concentric annular regions may be referred to as the distance vision degree regions. Between the concentric annular regions, the lens preferably has a base radial curvature degree. Between the concentric annular regions, the lens preferably has a curvature centered on the optical axis. The radial sagittal degree profile of the lens between the annular regions is preferably substantially the same as the radial sagittal degree profile of the central region. The lens preferably has a plurality of concentric additional annular regions. The additional annular regions are preferably separated from each other by a distance vision region having a base curvature degree.

[0056] At a point located at the midpoint from end to end of the radial width of each of the additional annular regions, the radial sagittal degree of the annular region preferably coincides with the average circumferential sagittal degree of the central region.

[0057] The curvature power of each of the additional annular regions may have the same value or the same power profile along any meridian of the annular region, i.e., the radial curvature power may be constant when viewed in the circumferential direction around the annular region. The base curvature power and the curvature providing the curvature power of the first annular region and any additional annular regions may be the curvature of the front surface of the lens. The base curvature power and the curvature providing the curvature power of the first annular region and any additional annular regions may be the curvature of the rear surface of the lens. The base curvature power and the curvature providing the curvature power of the first annular region and any additional annular regions may be the curvatures of the front and rear surfaces of the lens that provide a combined effect.

[0058] The contact lens may be a toric contact lens. For example, the toric contact lens may have an optical zone shaped to correct a person's astigmatism.

[0059] The contact lens may be made of an elastomer material, a silicone elastomer material, a hydrogel material, a silicone hydrogel material, or a mixture thereof. As is understood in the field of contact lenses, a hydrogel is a material that holds water in an equilibrium state and does not contain silicone-containing chemicals. A silicone hydrogel is a hydrogel that contains a silicone-containing chemical. The hydrogel materials and silicone hydrogel materials described in connection with the present disclosure 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). By way of comparison, the water content of the silicone elastomer materials described in connection with the present invention is about 0% to less than 10% (weight / weight). Typically, the water content of the silicone elastomer materials used in the methods or devices of the present invention is 0.1% to 3% (weight / weight). Examples of suitable lens formulations include formulations having the following United States Adopted Names (USAN), such as methafilcon A, ocufilcon A, ocufilcon B, ocufilcon C, ocufilcon D, omafilcon A, omafilcon B, comfilcon A, enfilcon A, stenfilcon A, fanfilcon A, etafilcon 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.

[0060] For example, the lens is preferably made of a hydrogel or silicone hydrogel contact lens having a lens diameter of 13 to 15 mm.

[0061] According to a second aspect, the present disclosure provides a method of manufacturing a contact lens. The method preferably includes a step of forming a contact lens, the contact lens having a central region, the central region having a center of curvature located on the optical axis. The contact lens has a first annular region. The first annular region has an off-axis center of curvature located at a first distance from the optical axis. The first annular region has a radial sagittal power profile that increases with a gradient of about 1.0 D / mm to about 20.0 D / mm as the radial distance from the optical axis increases. At a point located midway from end to end of the radial width of the first annular region, the radial sagittal power is equal to the average radial sagittal power of the central region.

[0062] The lens can have any of the virtues described with respect to the first aspect above.

[0063] The first annular region of the lens is tilted with respect to the central region. Due to the tilt of the first annular region with respect to the central region, the center of curvature of the first annular region is displaced to a position at a first distance from the optical axis. As a result of the tilt, the first annular region has a radial sagittal power profile that increases with a gradient of about 1.0 D / mm to about 20.0 D / mm as the radial distance from the optical axis increases, and at a point located midway from end to end of the radial width of the first annular region, the radial sagittal power is equal to the average radial sagittal power of the central region.

[0064] A method for manufacturing a contact lens includes tilting a first annular region relative to a central region such that the center of curvature of the first annular region is displaced to a location having a first distance from the optical axis, and having a radial sagittal power profile that increases with a gradient of about 1.0 D / mm to about 20.0 D / mm as the radial distance from the optical axis increases, and at a point located midway from end to end of the radial width of the first annular region, the radial sagittal power is made equal to the average radial sagittal power of the central region. In practice, for tilting, the tilt may be incorporated into the optical design of the front surface of the first annular region of the lens, or into the rear surface of the first annular region of the lens, or into both the front and rear surfaces of the first annular region of the lens. This 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 a bulk lens material. The method may further include curing the bulk lens material to form a lens.

[0065] The method may include casting a contact lens by causing polymerization of a contact lens formulation disposed between a female mold member and a male mold member of a contact lens mold assembly. As a variant, the method may include a step of lathing the surface of the contact lens. For example, the front surface of the contact lens may be cut using a lathe to provide desired optical properties.

[0066] The contact lens may be a molded contact lens. The lens may be formed by an injection molding process, a rotational molding process, or a lathing process, or a combination thereof. As will be understood by those skilled in the art, injection molding means forming a lens by disposing 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.

[0067] In a third aspect of the present disclosure, a method of using the contact lenses described herein is provided. The method may be effective in reducing the progression of refractive anomalies, for example, reducing the progression of myopia. When reducing the progression of myopia using the lenses of the present invention, the method includes the step of providing to a person who can accommodate the contact lenses to various near viewing distances (e.g., in the range from about 15 cm to about 40 cm). Some embodiments of the method include the step of providing an orthokeratology lens to a person between about 5 years old and about 25 years old. This providing step is preferably carried out by an eye care professional, such as an optician or an optometrist. As a variant, such a providing step may be carried out by a lens vendor who arranges for the delivery of the orthokeratology lens to the lens wearer.

[0068] Figure 1A is a schematic plan view of a prior art lens used when slowing down the progression of myopia (for example, myopia control). The lens 1 has an optical zone 2 that substantially covers the pupil and a peripheral zone 4 that is positioned to cover the iris. The peripheral zone 4 provides mechanical functions, such as functions of increasing the size of the lens, thereby making the lens 1 easier to handle, providing a stabilizing effect to prevent rotation of the lens 1, and providing a contoured area that improves the comfort of the wearer of the lens 1. The optical zone 2 provides the optical function of the lens 1, and the optical zone has an annular region 3 and a central region 5. With respect to this lens 1, the annular region 3 has a radial curvature power greater than the base curvature power of the central region 5. Figure 2A is a schematic ray diagram showing how the lens 1 focuses light when the lens 1 of Figures 1A and 1B is worn on the eye. The focal point 11 of the annular region 3 is located on a nearby focal plane 13, and the focal point 15 of the central region 5 is located on a distant focal plane 17 that is further away from the rear surface of the lens 1. The focal point 11 of the annular region 3 and the focal point 15 of the central region 5 share a common optical axis 19. As shown in Figures 2B and 2C, in the case of an infinite distance point source, the light rays focused by the central region 5 form a focused image 23 at the distant focal plane 17. The light rays focused by the central region 5 also produce a defocused, blurred spot 27 at the nearby focal plane 13. The light rays focused by the annular region 3 form a focused image 21 at the nearby focal plane 13. The light rays focused by the annular region 3 diverge after the nearby focal plane 13, and the diverging light rays produce a defocused annulus 25 at the distant focal plane 17. As described above, as a result of the defocused annulus image 25, the wearer of the lens 1 will see a "halo" around the focused distant image.

[0069] FIG. 3A is a schematic view of a lens 101 as an embodiment of the present invention. Similar to the prior art lens 1 shown in FIGS. 1A and 1B, the lens 101 has an optical zone 102 and a peripheral zone 104 surrounding the optical zone 102. The optical zone 102 has a central region 105 and a first annular region 103 surrounding the central region 105. As shown in FIG. 4A, the central region 105 has a center of curvature located on the optical axis 119. The first annular region 103 is inclined with respect to the central region 105, and the first annular region 103 has an off-axis center of curvature located at a first distance from the optical axis 119. The front surface of the first annular region 103 has a greater curvature than the front surface of the central region 105, and thus provides a curvature power greater than the base curvature power of the central region 105. FIG. 4D is a partial ray diagram of the lens 101 when the lens 101 of FIGS. 3A and 3B is worn on the eye, and shows a circle displaying the radius of curvature of the central distance region (the circle represented by the solid line) and the annular addition region (the circle indicated by the dashed line) of the lens 101. As shown in FIG. 4D, the front surface of the central region 105 forms a part of the surface of a sphere with a large radius 109. The front surface of the annular region 103 defines a curved annular surface with a small radius 106.

[0070] FIG. 4C is a diagram showing the light pattern at the far focal plane of the lens 101 formed from a far point source when the lens 101 of FIGS. 3A and 3B is worn on the eye. At this far focal plane 117, the light rays passing through the central region 105 are focused. The annular region 103 serves as an optical beam stop, and this optical beam stop results in a small spot size 133 (FIG. 4A) of light at the far focal plane 117 as shown in FIG. 4C.

[0071] Figure 4B is a diagram showing the light pattern at the vicinity of the focal plane near the lens 101 formed from a distant point source when the lens 101 of FIGS. 3A and 3B is mounted on the eye. A single image is not formed at the vicinity of the focal plane 113. As shown in FIG. 4B, at the vicinity of the focal plane 113, for an infinite distance point source, the light rays passing through the central region 105 produce a blurred circle 128, as in the case of the lenses of FIGS. 1A and 1B and FIGS. 2A and 2B. However, the light rays from the distant point source passing through the annular region 103 produce a focused annulus 122 as shown in FIG. 4B, and this focused annulus surrounds the blurred circle 128. FIG. 4B shows the light pattern produced for the distant point source. In contrast to the prior art lens 1 of FIG. 1, the lens 101 of FIGS. 3 and 4 does not produce a single image or an on-axis image at the vicinity of the nearby focal plane 113, and such an image may be used to eliminate the need for the eye to accommodate to nearby objects. In the case of an enlarged object located at a long distance, the focused image formed at the vicinity of the focal plane 113 is a convolution of (i) the focused image of the enlarged object obtained with a conventional lens having the optical power of the annular region 103, and (ii) the optical transfer function representing the optical effect of the annular region 103.

[0072] In contrast to the prior art lenses of FIGS. 1 and 2, the annular or "halo" effect does not occur at the distant focal plane 117.

[0073] FIG. 5 shows the radial curvature power profile of the lens 101 shown in FIGS. 3A and 3B. The radial curvature power, expressed in diopters (D), is plotted as a function of the radial distance from the optical axis 119 of the lens 101. The x-axis of the graph is labeled as the radial position expressed in mm (0.00 mm corresponds to the optical axis 119 of the lens). The lens 101 of FIGS. 3A and 3B has a base curvature power of -3.0 D across the entire central region, and the central region extends radially outward to a distance of about 2.00 mm from the optical axis 119. The annular region 103 has a curvature that provides a radial curvature addition power of +4.0 D. The radial curvature addition power is substantially constant across the entire width of the first annular region 103. As described above, the radial curvature power is a function of the curvature of the lens 101, i.e., the second derivative of the wavefront, and is not affected by the slope of the annular region 103 with respect to the central region 105.

[0074] FIG. 6 shows the radial sagittal power profile of the lens 101 shown in FIGS. 3A and 3B. The radial sagittal power, expressed in diopters (D), is plotted as a function of the radial distance from the optical axis 119 of the lens 101.

[0075] As shown in FIG. 6, across the entire central region 105 of the lens 101 extending out to a radial distance of about 2.00 mm, the radial sagittal power is substantially constant, and its value is -3.0 D. For the lenses shown in FIGS. 3 and 4, the annular region 103 is tilted such that the center of the circle defining the radius of curvature of the front surface of the annular region 103 is offset from the center of the circle defining the radius of curvature of the front surface of the central region 105. Since the radial sagittal power is a function of the slope of the lens surface, the tilt of the annular region 103 with respect to the central region 105 causes a change in the radial sagittal power across the entire annular region 103. This change in the radial sagittal power starts at a power that is more negative than the radial sagittal power of the central region 105 and increases to a radial sagittal power that is more positive than the radial sagittal power of the central region 105 as the radius increases, and is a ramp function 131. The slope of the radial sagittal power ramp 131 across the entire first annular region 103 depends on the tilt of the first annular region 103 with respect to the central region 105 and also depends on the curvature contribution power of the first annular region 103. The ramp 131 is curved, and its average slope is about 1.5 D / mm. The tilt of the annular region 103 is selected such that the radial sagittal power of the lens 301 at the radial midpoint of the annular region 103 (i.e., halfway between the ends of the radial width of the annular region 103) is equal to the average radial sagittal power of the central region 105.

[0076] FIG. 7 is a schematic diagram of another lens 201 as an embodiment of the present invention. The lens 201 has an optical zone 202 and a peripheral zone 204 surrounding the optical zone 202. The optical zone 202 has a central region 205, a first annular region 203 surrounding the central region 205, and a second concentric annular region 207 located in the radial direction longer from the central region 205 than the first annular region. Similar to the lens shown in FIG. 3A, the central region 205 has a center of curvature located on the optical axis. The first annular region 203 is inclined with respect to the central region 205, and the off-axis center of curvature of the first annular region 203 is located at a first distance from the optical axis. The front surface of the first annular region 203 has a greater curvature than the front surface of the central region 205, and provides a radial curvature power greater than the base curvature power of the central region 205. The first annular region 203 has a curvature that provides a radial curvature addition power of +4.0D.

[0077] The second annular region 207 is also inclined with respect to the central region 205, but is inclined by a different amount compared to the first annular region 203. The second annular region 207 has an off-axis center of curvature located at a first distance from the optical axis. The front surface of the second annular region 207 has a greater curvature than the front surface of the central region 205, and thus provides a radial curvature power greater than the base radial curvature power of the central region 205. The second annular region 207 also has a curvature that provides a radial curvature addition power of +4.0D.

[0078] FIG. 8 shows the radial curvature power profile of the lens 201 shown in FIG. 7. The radial curvature power, expressed in diopters (D), is plotted as a function of the radial distance from the center of the lens 201, and the radial position of 0.00 mm coincides with the optical axis. The lens 201 of FIG. 7 has a base radial curvature power of -3.0 D across the entire central region. The first annular region 203 has a curvature that provides a radial curvature addition power of +4.0 D. The radial curvature addition power is substantially constant across the width of the first annular region 203. The second annular region 207 also has a curvature that provides a radial curvature addition power of +4.0 D. A distance vision (distant vision) region 208 of the lens 201 having a curvature that provides the base radial curvature power is provided between the first annular region 203 and the second annular region 207.

[0079] FIG. 9 shows the sagittal power profile of the lens 201 shown in FIG. 7. The radial sagittal power, expressed in diopters (D), is plotted as a function of the radial distance from the optical axis, and the radial position of 0.00 mm coincides with the optical axis. Similar to the plot shown in FIG. 6, the change in the radial sagittal power is substantially constant (and equal) across the entire central region 205 of the lens 201.

[0080] The first annular region 203 is inclined such that the center of the circle defining the radius of curvature of the front surface of the annular region 203 is displaced with respect to the center of the circle defining the radius of curvature of the front surface of the central region 205. Since the radial sagittal power is a function of the gradient of the lens surface, the inclination of the annular region 203 with respect to the central region 205 causes a change in sagittal power across the entire annular region 203. This change in sagittal power starts at a power that is negative with respect to the radial sagittal power of the central region 205 and increases to a radial sagittal power that is positive with respect to the radial sagittal power of the central region 205 as the radius increases, and is a ramp function 231. The gradient of the radial sagittal power ramp 231 across the entire first annular region 203 depends on the inclination of the first annular region 203 with respect to the central region 205 and also depends on the radial curvature power addition of the first annular region 203. The ramp 231 is curved, and its average gradient is about 2.9 D / mm. The inclination of the annular region 203 is selected such that the radial sagittal power of the lens 201 at the radial midpoint of the first annular region 203 is equal to the average radial sagittal power of the central region 205.

[0081] The second annular region 207 is also inclined such that the center of the circle defining the radius of curvature of the front surface of the second annular region 207 is displaced with respect to the center of the circle defining the radius of curvature of the front surface of the central region 205. The inclination of the second annular region 207 with respect to the central region 205 causes a radial sagittal power profile to occur. This sagittal power profile starts at a power that is negative with respect to the radial sagittal power of the central region 205 at the inner edge of the annular region 203 and increases to a radial sagittal power that is positive with respect to the radial sagittal power of the central region 205 as the radius increases, and is a ramp function 233. The gradient of the second annular region 207 with respect to the central region 205 is different from the gradient of the first annular region 203. The sagittal power profile of the second annular region 207 is curved, and its average gradient is about 1.1 D / mm. The inclination of the annular region 203 is selected such that the sagittal power of the lens 201 at the radial midpoint of the first annular region 203 is equal to the average radial sagittal power of the central region 205.

[0082] A distance vision region 208 of the lens 201 is provided between the first annular region 203 and the second annular region 207. The distance vision region 208 between the first annular region 203 and the second annular region 207 nominally has the same diopter as the central region 205, but may have a negative diopter that is the same as, somewhat larger than, or somewhat smaller than that of the central region 205 according to the selection of the asphericity and common lens design practices.

[0083] FIG. 10 is a schematic view of another lens 301 as an embodiment of the present invention. Similar to the lens 201 shown in FIG. 7, the lens 301 has an optical zone 302 and a peripheral zone 304 surrounding the optical zone 302. The optical zone 302 has a central region 305, a first annular region 303 surrounding the central region 305, and a second concentric annular region 307 located at a longer radial distance from the central region 305 than the first annular region. Similar to the lenses shown in FIGS. 3A and 7, the central region 305 has a center of curvature located on the optical axis. The first annular region 303 is tilted with respect to the central region 305, and the first annular region 303 has an off-axis center of curvature located at a first distance from the optical axis. The front surface of the first annular region 303 has a larger curvature than the front surface of the central region 305, and thus provides a larger radial curvature diopter than the base curvature diopter of the central region 305. The front surface of the first annular region 303 has a larger curvature than the front surface of the central region 305, and thus provides a larger radial curvature diopter than the base radial curvature diopter of the central region 305. The first annular region 303 has a curvature that provides a radial curvature addition diopter of +8.0 D, that is, has a significantly larger radial curvature than the lens shown in FIG. 7.

[0084] The second annular region 307 is also tilted with respect to the central region 305, but is tilted by a different amount compared to the first annular region 303. The second annular region 307 has an off-axis curvature center located at a first distance from the optical axis. The front surface of the second annular region 307 has a greater curvature than the front surface of the central region 305, and thus provides a radial curvature power greater than the base radial curvature power of the central region 305. The second annular region 307 also has a curvature that provides a radial curvature addition power of +10.0D.

[0085] FIG. 11 shows the radial curvature power profile of the lens 301 shown in FIG. 10. The lens of FIG. 7 has a base radial curvature power of -3.0D across the entire central region 305. The radial curvature power, expressed in diopters (D), is plotted as a function of the radial distance from the center of the lens 301, and a radial position of 0.0 mm corresponds to the optical axis. The first annular region 303 has a curvature that provides a radial curvature addition power of +8.0D. The radial curvature addition power is substantially constant across the entire width of the first annular region 203. The second annular region 307 also has a curvature that provides a radial curvature addition power of +8.0D. Between the first annular region 303 and the second annular region 307, there is provided a distance vision region 308 of the lens 301 having a curvature that provides a base curvature power.

[0086] FIG. 12 shows the radial sagittal power profile of the lens 301 shown in FIG. 10. The radial sagittal power, expressed in diopters (D), is plotted as a function of the radial distance from the center of the lens 301, and a radial position of 0.00 mm corresponds to the optical axis. Similar to the lenses shown in FIGS. 3 and 7, the change in the radial sagittal power is substantially constant across the entire central region 305 of the lens 301.

[0087] The first annular region 303 is tilted such that the center of the circle defining the radius of curvature of the front surface of the annular region 303 is displaced relative to the center of the circle defining the radius of curvature of the front surface of the central region 305. Since the radial sagittal power is a function of the gradient of the lens surface, the tilt of the annular region 303 relative to the central region 305 results in a sagittal power change or profile across the entire annular region 303. This sagittal power change or profile starts at a power that is more negative than the radial sagittal power of the central region 305 at the inner edge of the annular region 303 and increases to a radial sagittal power that is more positive than the radial sagittal power of the central region 305 at the outer edge of the annular region 303 as the radius increases, which is a ramp function 331. The radial curvature contribution power 303 of the first annular region (shown in FIG. 11) is significantly greater than the radial curvature power of the first annular region 303 of the lens 201 shown in FIG. 7. As a result, the gradient of the radial sagittal power profile is steep across the entire first annular region 303. The ramp 331 is curved, and the average gradient is about 5.5 D / mm. The tilt of the annular region 303 is selected such that the radial sagittal power of the lens 301 at the radial midpoint of the first annular region 303 is equal to the average radial sagittal power of the central region 305.

[0088] The second annular region 307 is also tilted such that the center of the circle defining the radius of curvature of the front surface of the second annular region 307 is displaced relative to the center of the circle defining the radius of curvature of the front surface of the central region 305. The tilt of the second annular region 307 relative to the central region 305 results in a radial sagittal power profile that starts at a power that is more negative than the radial sagittal power of the central region 305 at the inner edge of the annular region 303 and increases to a radial sagittal power that is more positive than the radial sagittal power of the central region 305 as the radius increases, which is a ramp function 333. The tilt of the second annular region 307 relative to the central region 305 is different from the tilt of the first annular region 303.

[0089] The lamp 333 is curved and has an average gradient of about 2.2 D / mm. The inclination of the annular region 303 is selected such that the radial sagittal power of the lens 301 at the radial midpoint of the first annular region 303 is equal to the average radial sagittal power of the central region 305.

[0090] An intermediate vision region 308 of the lens 301 is provided between the first annular region 303 and the second annular region 305. The intermediate vision region 308 between the first annular region 303 and the second annular region 307 nominally has the same power as the central region 305, but may have a negative power that is the same as, somewhat larger than, or somewhat smaller than that of the central region 305, depending on the selection of the asphericity and common lens design practices.

[0091] As described above, regarding the lens as an embodiment of the present invention, the gradient of the radial sagittal power distribution across the entire annular region depends on the radial curvature power of the annular region and also depends on the inclination of the annular region with respect to the central region of the lens. FIG. 13A shows the radial sagittal power curves as a function of the radial distance from the optical axis for lenses having different radial curvature powers ranging from +2.0D to +10.0D. Each lens has two concentric annular regions, and the first annular region (shown as region 403) is closer to the central region (shown as region 405) than the second annular region (shown as region 407). For each lens, the radial sagittal power across the entire central region 405 is substantially constant. For each lens, at the boundary between the central region and the first annular region, as a result of the inclination of the first annular region 403 with respect to the central region, a drop in the radial sagittal power occurs. For each lens, the relative inclination of the first annular region with respect to the central region is the same. For each lens, the sagittal power increases across the entire width of the first annular region. Between the first annular region and the second annular region, a distance vision region (shown as region 408) of the lens having substantially the same power as the central region is provided. For each lens, at the boundary between the distance vision region and the second annular region, the sagittal power also drops in this case as a result of the inclination of the second annular region with respect to the central region and with respect to the distance vision region. For each lens, the radial sagittal power increases across the entire width of the second annular region. For each lens, the inclination of the second annular region with respect to the central region is the same. As the radial curvature power of the lens increases, the gradient of the radial sagittal power ramp across the entire first annular region and across the entire second annular region increases. For example, the gradient of the radial sagittal power ramp for the +10.0D lens (shown by curve 445) is greater than the gradient of the radial sagittal power ramp for the +2.0D lens (shown by curve 447).FIG. 13B is a plot showing how the gradient of the radial sagittal degree lamp changes with the change in the radial curvature participation degree for the first annular region (shown by curve 549) and for the second annular region (shown by curve 551). The gradient of the radial sagittal degree lamp increases with the increase in the radial curvature participation degree, and the radial sagittal degree gradient across the second annular region is smaller than the radial sagittal degree gradient across the first annular region.

[0092] In the above description, integers or elements having known obvious or predictable equivalents have been referred to, but such equivalents shall be considered as being described herein as if they were individually described. Reference should be made to the claims that define the true scope of the invention, which should be considered to include any such equivalents. Also, as will be understood by the reader, the integers or features of the present disclosure described as being advantageous, convenient, etc. are optional and do not limit the scope of the independent claims. Further, it should be understood that although some embodiments of the present invention are considered to be beneficial, such optional integers or features may not be desirable and thus may not be described in other embodiments.

Claims

**Claim 1** A contact lens, wherein the contact lens has an optical zone, and the optical zone has a central region, and the central region has a center of curvature located on the optical axis, has a first annular region, and the first annular region has an off-axis center of curvature located at a first distance from the optical axis, the first annular region has a radial sagittal power profile that increases with a gradient of about 1.0 D / mm to about 20.0 D / mm as the radial distance from the optical axis increases, and at a point located midway from end to end of the radial width of the first annular region, the radial sagittal power is equal to the average radial sagittal power of the central region. A contact lens. **Claim 2** The contact lens according to claim 1, wherein the radial sagittal power profile across the entire first annular region is linear. **Claim 3** The contact lens according to claim 1 or 2, wherein the radial sagittal power profile across the entire first annular region defines a curve having an average gradient of about 1.0 D / mm to about 20.0 D / mm. **Claim 4** The contact lens according to any one of claims 1 to 3, wherein the first annular region has a radial sagittal power profile that increases with a gradient of about 4.0 D / mm to about 12.0 D / mm as the radial distance from the optical axis increases. **Claim 5** The contact lens according to any one of claims 1 to 3, wherein the first annular region has a radial sagittal power profile that increases with a gradient of about 1.0 D / mm to about 6.0 D / mm as the radial distance from the optical axis increases. **Claim 6** The contact lens according to any one of claims 1 to 5, wherein the radial sagittal power at the inner edge of the first annular region is 0.5 D to 2.5 D less than the radial sagittal power at the outer edge of the central region. **Claim 7** The contact lens according to any one of claims 1 to 6, wherein the radial sagittal power at the outer edge of the first annular region is 0.5 D to 2.0 D greater than the radial sagittal power at the outer edge of the central region. **Claim 8** The contact lens according to any one of claims 1 to 7, wherein the first annular region has a curvature that provides a radial curvature addition power, and the radial curvature addition power is +2.0 D to +10.0 D. **Claim 9** The central region has a curvature that provides a base radial curvature power, and the base radial curvature power is from 0.5 D to -15.0 D. The contact lens according to any one of claims 1 to 8.

10. The first annular region extends radially outward from around the central region by 0.5 to 1.5 mm. The contact lens according to any one of claims 1 to 9.

11. It has at least one additional annular region concentric with the first annular region. Each of the additional annular regions has an off-axis curvature center located at a first distance from the optical axis. Each annular region has a sagittal power profile that increases with a gradient of about 1.0 D / mm to about 20.0 D / mm as the radial distance from the optical axis increases. The contact lens according to any one of claims 1 to 10.

12. Each of the additional annular regions has a radial sagittal power gradient different from that of the first annular region. The contact lens according to claim 11.

13. The radial sagittal power gradient of each of the additional annular regions depends on the radial position of the annular region. The contact lens according to claim 11 or 12.

14. At a point located midway from end to end of the radial width of each of the additional annular regions, the radial sagittal power is equal to the average radial sagittal power of the central region. The contact lens according to any one of claims 11 to 13.

15. It has a plurality of concentric additional annular regions, and the additional annular regions are separated from each other by a distance vision region having the base radial curvature power. The contact lens according to any one of claims 11 to 14.

16. The base radial curvature power of the central region results from the curvature of the front surface and / or the rear surface of the contact lens. The contact lens according to any one of claims 9 to 15.

17. The radial curvature powers of the first annular region and any additional annular regions result from the curvature of the front surface and / or the rear surface of the contact lens. The contact lens according to any one of claims 8 to 16.

18. The contact lens according to any one of claims 1 to 17, which is made of an elastomer material, a silicone elastomer material, a hydrogel material, a silicone hydrogel material, or a mixture thereof.

19. The contact lens according to any one of claims 1 to 18, which is a molded contact lens.

20. A method for manufacturing the contact lens according to any one of claims 1 to 19, the method comprising: a step of forming a contact lens, the contact lens having: a central region having a center of curvature located on the optical axis; a first annular region having an off-axis center of curvature located at a first distance from the optical axis; the first annular region having a radial sagittal power profile that increases with a gradient of about 1.0 D / mm to about 20.0 D / mm as the radial distance from the optical axis increases, and at a point located midway between the ends of the radial width of the first annular region, the radial sagittal power being equal to the average radial sagittal power of the central region.

21. A method for suppressing the progression of myopia, the method comprising: providing the contact lens according to any one of claims 1 to 19 to a myopic person who can accommodate the eye according to various near viewing distances.

Images