Contact lenses and related methods

Abstract

A contact lens (2001) and a method for manufacturing such a lens (2001) are described. The contact lens (2001) comprises an optical zone (202). The optical zone (202) includes a central portion (205) having a center of curvature on the optical axis (219) and a first annular portion (203) extending radially outward from the central portion (205). The first annular portion (203) provides additional refractive power. One of the front and rear surfaces of the first annular portion (203) has a center of curvature on the optical axis (219). The other of the front and rear surfaces of the first annular portion (203) has a center of curvature at a first distance from the optical axis (219).

Description

Technical Field

[0001] The present invention relates to contact lenses. In particular (but not exclusively), the present invention relates to contact lenses for slowing the progression of myopia. The present invention also relates to a method of manufacturing such lenses.

Background Art

[0002] Many people, including children and adults, require contact lenses to correct myopia (nearsightedness). In a myopic eye, incident light from a distant object is focused at a position in front of the retina. As a result, the light converges towards a plane in front of the retina, diverges towards the retina, and is out of focus when it reaches the retina. Conventional lenses for correcting myopia (e.g., spectacle lenses or contact lenses) reduce the convergence of light (in the case of contact lenses) or cause the divergence of the incident light (in the case of spectacles) before the incident light from a distant object reaches the eye, thereby moving the position of the focus onto the retina.

[0003] Decades ago, it was suggested that the progression of myopia in children and adolescents could be slowed or prevented by undercorrection, that is, by bringing the focal point closer to the retina but not completely onto it. However, this approach inevitably results in a decrease in distance vision compared to the vision obtained with lenses that fully correct myopia. Furthermore, the effectiveness of undercorrection in controlling the progression of myopia is now considered questionable. A more recent approach to correcting myopia is to provide lenses that have both one or more regions that provide full correction of distance vision and one or more regions that undercorrect, i.e., intentionally induce myopic defocus. This approach has been suggested to be able to prevent or slow the onset or progression of myopia in children and adolescents while providing good distance vision. In lenses that have areas that provide defocus (blurring), the area that provides complete correction of distance vision is usually called the base refractive power area, and the area that provides undercorrection or intentionally induces myopic defocus is usually called the myopic defocus area or additional refractive power area (where the refractive power is more positive or less negative than the refractive power (diopter) of the distance area).

[0004] The surface of the additional refractive power region (typically the anterior surface) has a smaller radius of curvature than the distance refractive power region and therefore provides the eye with a greater positive or less negative refractive power (power). The additional refractive power region is designed to focus incoming parallel light (i.e., light from a distance) into the eye in front of the retina (i.e., closer to the lens). The distance refractive power region is designed to focus light to form an image on the retina (i.e., closer to the lens).

[0005] A known type of contact lens that reduces the progression of myopia is the bifocal contact lens, available under the name MISIGHT (CooperVision, Inc.). Unlike bifocal or multifocal contact lenses configured to improve presbyopic vision, this bifocal lens is composed of predetermined optical dimensions that allow for the use of distance correction (i.e., base refractive power) to see both distant and near objects. The therapeutic zone of the bifocal lens with additional refractive power provides a myopic defocused image at both distant and near viewing distances.

[0006] While these lenses have been found to be beneficial in preventing or slowing the onset or progression of myopia, the annular additional refractive power area can cause undesirable visual side effects. Light focused by the annular additional refractive power area in front of the retina diverges from the focal point, forming a defocused ring on the retina. Therefore, wearers of these lenses may see a ring or "halo" around the image formed on the retina, especially with small, bright objects such as streetlights or car headlights. Also, theoretically, instead of using the eye's natural accommodation (i.e., the eye's natural ability to change its focal length) to focus on near objects, the wearer could utilize the additional focal point in front of the retina resulting from the annular additional refractive power area to focus on near objects. In other words, the wearer could use the lenses unconsciously (without realizing it) in the same manner as presbyopia-correcting lenses, which is undesirable for younger individuals.

[0007] It is recognized that providing lenses that introduce additional myopic defocus may be beneficial for the treatment of myopia. Similarly, providing lenses that extend the depth of focus may be beneficial for the treatment of presbyopia.

[0008] Further lenses have been developed that can be used to treat myopia and are designed to eliminate the halo observed around the focal image. In these lenses, an annular region is configured so that the axial image is not formed in front of the retina, thereby preventing such an image from being used to avoid the eye having to adapt to a near target. Rather, a distant point light source is imaged by the annular region into a ring-shaped focal line at the near additional refractive power focal plane, resulting in a small spot-sized light on the retina at the distant focal plane without the surrounding "halo" effect. [Overview of the Initiative]

[0009] According to a first aspect, the disclosure provides a contact lens having an optical zone. The optical zone includes a central portion having a center of curvature on the optical axis. The optical zone includes a first annular portion extending radially outward from the central region. The first annular portion provides additional refractive power due to radial curvature. One of the front and rear surfaces of the first annular portion has a center of curvature on the optical axis. The other of the front and rear surfaces of the first annular portion has a center of curvature at a first distance from the optical axis.

[0010] According to a second aspect, the present disclosure provides a method for manufacturing a contact lens according to the first aspect. The method comprises the step of forming a contact lens. The contact lens comprises an optical zone. The optical zone includes a central portion having a center of curvature on the optical axis and a first annular portion extending radially outward from the central region. The first annular portion provides radial curvature additional refractive power. One of the front and rear surfaces of the first annular portion has a center of curvature on the optical axis. The other of the front and rear surfaces of the first annular portion has a center of curvature at a first distance from the optical axis.

[0011] According to a third aspect, the disclosure provides a method for suppressing the progression of myopia. The method comprises the step of providing a contact lens according to the first aspect to a person with myopia who can adapt to changing near distances.

[0012] Of course, it will be understood that features described in relation to one aspect of the Disclosure may be incorporated into other aspects of the Disclosure. For example, a method of the Disclosure may incorporate features described with reference to an apparatus of the Disclosure, and vice versa.

[0013] Herein, an embodiment of the present invention will be described for illustrative purposes only, with reference to the attached schematic diagram. [Brief explanation of the drawing]

[0014] [Figure 1A] Figure 1A is a schematic plan view of the surface of a contact lens according to one embodiment of the present disclosure.

[0015] [Figure 1B] Figure 1B is a side view of the lens surface shown in Figure 1A.

[0016] [Figure 2A] Figure 2A is a ray diagram of the lens surface shown in Figure 1A.

[0017] [Figure 2B] Figure 2B shows the optical pattern at the proximal focal plane of the lens surface in Figure 1A, formed from a distant point source.

[0018] [Figure 2C] Figure 2C shows the light pattern at the distal focal plane of the lens surface in Figure 1A, formed from a distant point source.

[0019] [Figure 3] Figure 3 is a partial ray diagram of the lens surface shown in Figures 1A and 1B. Circles indicating the radius of curvature of both the central distance-vision region (dotted line) and the annular additional region (dashed line) of the contact lens are shown.

[0020] [Figure 4A] Figure 4A is a plot (graph) showing the change in sagittal refractive power in the radial direction of the lens surface shown in Figures 1A and 1B.

[0021] [Figure 4B] Figure 4B is a plot (graph) showing the change in the radial curvature refractive power of the lens surface shown in FIGS. 1A and 1B.

[0022] [Figure 5A] FIG. 5A is a schematic plan view of the surface of a contact lens according to an embodiment of the present disclosure, which has an astigmatic optical system.

[0023] [Figure 5B] FIG. 5B is a side view of the lens surface of FIG. 5A. <00OO098>

[0024] [[ID=2o]] [Figure 6A] FIG. 6A is a ray diagram of the lens surface of FIGS. 5A and 5B.

[0025] [Figure 6B] FIG. 6B shows the light pattern at the proximal focal plane of the lens surface of FIGS. 5A and 5B, formed from a distant point source.

[0026] [Figure 6C] FIG. 6C shows the light pattern at the distal focal plane of the lens surface of FIGS. 5A and 5B, formed from a distant point source.

[0027] [Figure 6D] FIG. 6D is a partial ray diagram of the lens surface of FIGS. 5A and 5B. Circles showing the radii of curvature of the central distant region (dash-dotted line) and the annular additional region (dashed line) of the lens surface are both shown.

[0028] [Figure 7A] FIG. 7A is a plot (graph) showing the change in the radial sagittal refractive power of the lens surface shown in FIGS. 5A and 5B.

[0029] [Figure 7B]Figure 7B is a plot (graph) showing the change in refractive power due to the radial curvature of the lens surface shown in Figures 5A and 5B.

[0030] [Figure 8A] Figure 8A is a plan view of a contact lens according to one embodiment of the present disclosure.

[0031] [Figure 8B] Figure 8B is a side view of the contact lens shown in Figure 8A.

[0032] [Figure 9] Figure 9 is a partial ray diagram of the lens shown in Figures 8A and 8B. Circles indicating the radius of curvature of both the central distance-vision region (dotted line) and the annular additional region (dashed line) of the contact lens are shown.

[0033] [Figure 10A] Figure 10A is a plot (graph) showing the change in refractive power due to the radial curvature of the lens shown in Figures 8A and 8B.

[0034] [Figure 10B] Figure 10B is a plot (graph) showing the change in sagittal refractive power in the radial direction of the lens shown in Figures 8A and 8B.

[0035] [Figure 11A] Figure 11A is the ray diagram of the lenses shown in Figures 8A and 8B.

[0036] [Figure 11B] Figure 11B shows the light pattern at the distal focal plane of the lens surface in Figures 8A and 8B, formed from a distant point source.

[0037] [Figure 11C] Figure 11C shows the light pattern at the first proximal focal plane of the lens surface in Figures 8A and 8B, formed from a distant point source.

[0038] [Figure 11D] Figure 11D shows the light pattern at the second proximal focal plane of the lens surface in Figures 8A and 8B, formed from a distant point source.

[0039] [Figure 12] Figure 12 is a flowchart showing a method for manufacturing a lens according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0040] In a first aspect, the disclosure provides a contact lens having an optical zone. The optical zone includes a central portion having a center of curvature on the optical axis, and a first annular portion extending radially outward from the central region. The first annular portion provides additional refractive power due to radial curvature. One of the front and rear surfaces of the first annular portion has a center of curvature on the optical axis. The other of the front and rear surfaces of the first annular portion has a center of curvature at a first distance from the optical axis.

[0041] The surface of the first annular portion having a center of curvature on the optical axis focuses light from a far-point source on the optical axis that is incident on the lens in a direction parallel to the optical axis of the lens to a point on the optical axis. The surface of the first annular portion having a center of curvature at a distance of 1 from the optical axis focuses light from a far-point source on the optical axis that is incident on the lens in a direction parallel to the optical axis of the lens to a point at a distance of 2 from the optical axis.

[0042] The front and rear lens surfaces of the first annular section are aligned to share a common optical axis.

[0043] As used herein, the term contact lens refers to an ophthalmic lens that can be placed on the front of the eye. It will be understood that such contact lenses provide clinically acceptable on-eye movement and do not adhere to a person's eye. Contact lenses can be in the form of corneal lenses (e.g., lenses that rest on the cornea of ​​the eye). Contact lenses can be soft contact lenses, such as hydrogel contact lenses or silicone hydrogel contact lenses.

[0044] The contact lens according to this disclosure comprises an optical zone. The optical zone includes a lens portion having an optical function. The optical zone is configured to be positioned over the pupil of the eye when in use. In the case of the contact lens according to this disclosure, the optical zone includes a central portion and a first annular portion extending radially outward from the central portion. The optical zone may include a number of additional annular portions concentric with the first annular portion. The optical zone may be surrounded by a peripheral zone. The peripheral zone is not part of the optical zone but is located outside the optical zone and above the iris when the lens is worn and provides mechanical functions such as increasing the size of the lens to make it easier to handle, providing ballast to prevent the lens from rotating, and / or providing a shape area to improve the comfort of the lens wearer. The peripheral zone may extend to the edge of the contact lens.

[0045] A contact lens according to one embodiment of the present disclosure may include ballast for orienting the lens when positioned over the wearer's eye. Embodiments of the present disclosure incorporating ballast into the contact lens rotate to a predetermined angle of repose by the action of the wearer's eyelid when placed over the wearer's eye. For example, the ballast may be a wedge, and the rotation may be caused by the action of the eyelid on the wedge. Ballasting contact lenses to orient them is well known in the art. For example, toric contact lenses are ballasted to orient the lens so that the orthogonal cylindrical correction provided by the lens aligns precisely with the astigmatism of the wearer's eye.

[0046] The contact lens may be substantially circular in shape and may have a diameter of approximately 4 mm to approximately 20 mm. The optical zone may be substantially circular in shape and may have a diameter of approximately 2 mm to approximately 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.

[0047] The optical axis may lie along the centerline of the lens. The central region can focus (converge) light from a distant point object on the optical axis to a spot on the optical axis at the distal focal plane. As used herein, the term focal plane refers not to a physical surface, but to a plane through which light from a distant object can be traced. Such a plane is also called the image plane (which may be a curved surface) or image shell. The eye focuses light onto the curved retina. 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. Nevertheless, in the art, the curved surface of the retina is generally referred to as a (planar) plane.

[0048] The central part of the lens may be substantially circular in shape and may have a diameter of about 2 mm to about 9 mm, preferably about 2.5 mm to about 4 mm. The central part may also be substantially elliptical in shape.

[0049] The first annular portion may extend radially outward from the periphery of the central portion for a distance of about 0.1 mm to about 4 mm, preferably about 0.5 mm to about 1.5 mm. The radial width of the first annular portion may therefore be about 0.1 mm to about 4 mm, preferably about 0.5 mm to about 1.5 mm. The periphery of the central portion may define a boundary between the central portion and the first annular portion, and therefore the first annular portion may be adjacent to the central portion.

[0050] In the context of this disclosure, the first annular portion is a substantially annular portion surrounding the central portion. It may be substantially circular or substantially elliptical. It may completely surround the central portion. It may partially surround the central portion. The first annular portion may abut the central portion. A blending region may be provided between the central portion and the first annular portion. The blending region should not substantially affect the optical system provided by the central portion and the first annular portion, and the blending region may have a radial width of 0.05 mm or less. However, in some embodiments, it may be about 0.2 mm wide or about 0.5 mm wide.

[0051] The central portion of the lens has a front surface. This front surface is a forward-facing surface that does not come into contact with the wearer's eye when the contact lens is worn by the wearer. The central portion of the lens has a rear surface. This rear surface is a backward-facing surface that comes into contact with the wearer's eye when the contact lens is worn by the wearer. The first annular portion also has a front surface, which is a forward-facing surface that does not come into contact with the wearer's eye when the contact lens is worn by the wearer. The first annular portion also has a rear surface, which is a backward-facing surface that comes into contact with the wearer's eye when the contact lens is worn by the wearer.

[0052] As used herein, the term sagittal refractive power (also called axial refractive power or inclined base refractive power) at a point on the lens surface is used to describe the optical refractive power of a lens obtained using the position at which a ray passing through the lens surface intersects the optical axis of the lens (for this reason, sagittal refractive power is also called axial refractive power). Curvature refractive power (also called local refractive power or instantaneous refractive power) is the refractive power provided by the radius of curvature at a point on the lens surface. In the prior art, when refractive power changes are plotted according to the radius of the lens, sagittal refractive power is usually plotted.

[0053] As those skilled in the art will understand, sagittal refractive power can be calculated from the slope (i.e., the first derivative) of the wavefront that has passed through the lens (for this reason, sagittal refractive power is also called slope-based refractive power). Curvature refractive power can be calculated from the second derivative of the wavefront that has passed through the lens. The wavefront can be measured using a Shack-Hartmann wavefront sensor. For example, curvature refractive power and sagittal refractive power can be understood as follows:

[0054] For a certain spherical wavefront W, at a point at a radial distance r (pupil radius) from a line perpendicular to the center of the wavefront, W(r) = A*r 2 Here, A is a function. The wavefront curvature, i.e., the curvature refractive power Pc, is a function of the second derivative of the wavefront. The wavefront slope, i.e., the sagittal refractive power Ps, is a function of the first derivative of the wavefront and changes with the slope (gradient) of the wavefront.

[0055] For a simple spherical lens, the curvature refractive power Pc is as follows: JPEG2026524773000002.jpg942 For a simple spherical lens, the sagittal refractive power Ps is as follows: JPEG2026524773000003.jpg936 Therefore, in the case of a simple coaxial lens with a spherical wavefront assuming a paraaxial orientation, Pc = Ps, as mentioned above.

[0056] In this specification, radial curvature refractive power is defined as the curvature refractive power in the direction extending radially outward from the optical axis of the lens. In this specification, circumferential curvature refractive power is defined as the curvature refractive power in a constant radial coordinate extending along the circumference of the lens.

[0057] In this specification, radial sagittal refractive power is defined as the sagittal refractive power in the direction extending radially outward from the optical axis of the lens. In this specification, circumferential sagittal refractive power is defined as the sagittal refractive power in a constant radial coordinate extending along the circumference of the lens.

[0058] In the case of low-aberration optical systems (e.g., single-focus lenses), the sagittal and curvature refractive powers may be the same or similar. However, in recently developed myopia-suppressing lenses employing "non-coaxial optical systems," the sagittal and curvature refractive powers can differ significantly. These lenses have surface regions that focus light from an on-axial light source to a region offset from the optical axis. Therefore, the distance at which the local beam of light converges at the focal point can differ significantly from the distance at which it intersects the optical axis of a larger composite lens. In these types of lenses, the distinction between sagittal (axial) refractive power and curvature (local) refractive power becomes important. In non-coaxial optical systems, i.e., optical systems where at least some focusing regions form foci that are not on the optical axis of the lens, explaining only the curvature refractive power or only the sagittal refractive power does not provide a complete explanation of the optical system. Adjacent regions of a lens may have the same curvature refractive power, but their sagittal refractive powers may differ (rays from each region intersect the optical axis at different distances from each other and from the local focal length). For example, in a lens containing non-coaxial lenslets, the resulting sagittal and curvature refractive power values ​​can vary significantly. The curvature refractive power map of such a lens shows a consistent additional refractive power for each lenslet, while the sagittal refractive power map shows the sagittal refractive power of a lenslet that varies with radial distance, i.e., the distance of a point on the lens surface from the optical axis in the direction perpendicular to the optical axis.

[0059] In some embodiments of the present disclosure, the radial sagittal refractive power of the central portion of the lens is obtained, in whole, from the radial sagittal refractive power of the front surface of the central portion and the radial sagittal refractive power of the rear surface of the central portion.

[0060] Similarly, the radial sagittal refractive power of the first annular portion of the lens is obtained, in whole, from the radial sagittal refractive power of the front surface of the first annular portion and the radial sagittal refractive power of the rear surface of the first annular portion.

[0061] Similarly, the radial curvature refractive power of the central part of the lens is obtained as a whole from the radial curvature refractive power of the front surface of the central part and the radial curvature refractive power of the rear surface of the central part.

[0062] Similarly, the radial curvature refractive power of the first annular portion of the lens is obtained, as a whole, from the radial curvature refractive power of the front surface of the first annular portion and the radial curvature refractive power of the rear surface of the first annular portion.

[0063] The central portion of the lens may have the same radial curvature refractive power as the radial sagittal refractive power. This is referred to herein as the base radial curvature refractive power, base radial sagittal refractive power, or base radial refractive power. The nominal refractive power of the central portion will correspond to the labeled refractive power (power) of the contact lens, as provided on the contact lens packaging (although in practice they may not be the same value). This would be the average sagittal refractive power or average curvature refractive power measured over the central portion (overall) in the radial and circumferential directions. The measured refractive power of the central portion is the average curvature refractive power or average sagittal refractive power measured directly over the central portion (overall) in the radial and circumferential directions. This may differ from the nominal refractive power.

[0064] For lenses used to treat myopia, the base refractive power is negative or near zero, with the central portion correcting distance vision. The base refractive power can be between 0.5 diopters (D) and -15.0 diopters. The base refractive power can range from -0.25D to -15.0D.

[0065] The front surface of the central section may have the same radial curvature refractive force as the rear surface of the central section. Alternatively, the front surface of the central section may have a different radial curvature refractive force than the rear surface of the central section. The radial curvature refractive force of the central section as a whole may be referred to below as the radial curvature refractive force of the base.

[0066] The front surface of the central section may have the same radial sagittal refractive force as the rear surface of the central section. Alternatively, the front surface of the central section may have a different radial sagittal refractive force than the rear surface of the central section. The radial sagittal refractive force of the central section as a whole may be referred to below as the radial sagittal refractive force of the base.

[0067] In some embodiments of this disclosure, the radial curvature refractive power of the first annular portion is greater than the radial curvature refractive power of the base of the central portion. Hereinafter, the difference in radial curvature refractive power between the first annular portion and the central portion may be referred to as the additional radial curvature refractive power. The circumferential curvature refractive power of the first annular portion may be the same as the circumferential curvature refractive power of the central portion. The net radial curvature refractive power of the first annular portion is the sum of the radial curvature refractive power of the base and the additional radial curvature refractive power. For example, in a lens where the radial curvature refractive power of the base is -3.0D and the additional radial curvature refractive power of the first annular portion is +4.0D, the net radial curvature refractive power of the first annular portion is +1.0D.

[0068] In some embodiments of this disclosure, both the front and rear surfaces of the first annular portion provide radial curvature additional refractive power. The radial curvature additional refractive power of the front surface may be the same as that of the rear surface. The radial curvature additional refractive power of the front surface may be different from that of the rear surface. A surface of the first annular portion having a curvature center on the optical axis may provide radial curvature additional refractive power of +0.5D to +4.0D, preferably +2.0D to +3.0D. A surface of the first annular portion having a curvature center at a first distance from the optical axis may provide radial curvature additional refractive power of +4.0D to +20.0D, for example, +10.0D. A surface of the first annular portion having a curvature center at a first distance from the optical axis may provide a greater radial curvature additional refractive power than a surface of the first annular portion having a curvature center on the optical axis.

[0069] The base curvature refractive power of the lens may be positive, and the first annular portion may have a positive additional radial curvature refractive power greater than the base curvature refractive power. In this case, the additional refractive power focal plane is closer to the lens than the distal focal plane. No on-axial image is formed by light passing through the annular portion. Therefore, the wearer of the lens must use the natural accommodation of the eye to focus on nearby objects. The rays focused by the annular portion may not intersect the optical axis of the contact lens at all, or may only intersect after passing through the additional refractive power focal plane.

[0070] The base curvature refractive power of the lens may be negative, and the first annular region may have a negative radial curvature additional refractive power that is smaller (less negative) than the refractive power of the base region, or the first annular region may have a positive curvature refractive power. Considering a lens positioned on the cornea, if the curvature additional refractive power of the first annular region is negative (less negative) than the base refractive power, the additional refractive power focal plane may be anterior to the eye than the distal focal plane. Considering a lens not positioned on the cornea, if the curvature additional refractive power of the first annular region is positive, the additional refractive power focal plane is on the opposite side (image side) from the distal focal plane of the lens (the virtual focal plane on the object side of the lens), and if the curvature additional refractive power of the first annular region is negative (but less negative than the base curvature refractive power), the virtual additional refractive power focal plane is farther from the lens than the virtual distal focal plane.

[0071] The additional refractive power due to the radial curvature of the first annular portion of the lens is, overall, +0.5D to +20.0D, preferably +4.0D to +10.0D.

[0072] The radial curvature-added refractive power of the first annular portion of the lens may have the same value or the same refractive power profile along all meridians of the first annular portion. That is, the radial curvature-added refractive power may be constant in the circumferential direction around the first annular portion.

[0073] In some embodiments of the present disclosure, one of the front and rear surfaces of the first annular portion has a center of curvature on the optical axis. The surface has a radial sagittal refractive power greater than the radial sagittal refractive power of the central portion of the lens (i.e., the surface provides a radial sagittal additional refractive power). The radial sagittal additional refractive power provided by the surface may be substantially constant over the radial width of the first annular portion.

[0074] The front and rear surfaces of the first annular portion have centers of curvature located at a first distance from the optical axis. The surface of the first annular portion is inclined with respect to the central portion of the lens. As used herein, the inclination of the first annular portion means radial inclination, not lateral inclination. Thus, for example, in the radial cross-section of the lens, the outer end of the curve defining the surface of the first annular portion may be shifted above or below its position in the corresponding (hypothetical) uninclined annular portion. Correspondingly, in three dimensions, the circumferential (circumferentially extending) boundary of the first annular portion (formed by the ends of the radial curve) may be shifted above or below its position in the corresponding uninclined annular portion. When the surface of the first annular portion is inclined with respect to the central portion, the center of curvature of that surface is shifted by a first distance from the optical axis. When the surface of the first annular portion is inclined with respect to the central portion, the radial sagittal refractive power of the first annular portion changes, because it is a function of the first derivative of the wavefront. As a result of this inclination, the radial sagittal refractive power on the surface changes over the width of the first annular portion.

[0075] For the surface of the first annular portion having a center of curvature at a first distance from the optical axis, the degree of inclination can be selected such that the radial sagittal refractive power at a point half the radial width of the surface is equal to the average radial sagittal refractive power at the center of the lens.

[0076] For the surface of a first annular portion having a center of curvature located at a first distance from the optical axis, the average radial sagittal additional refractive power over the radial width of the surface may be zero.

[0077] Alternatively, the surface of the first annular portion, having a center of curvature at a first distance from the optical axis, may provide a radial sagittal additional refractive power in addition to being radially inclined with respect to the central portion. The radial sagittal additional refractive power may be between +0.5D and +4.0D, for example, +2.0D. In this case, both the front and rear surfaces of the first annular portion provide a radial sagittal additional refractive power greater than zero over the radial width of the first annular portion.

[0078] For the surface of the first annular portion having a center of curvature at a first distance from the optical axis, a radial sagittal refractive power profile, which is a ramp function, can be produced depending on the degree of inclination. It may start negative, which is greater (greater negative) than the radial sagittal refractive power at the outer edge of the central portion, and may increase as the radial distance from the optical axis of the lens increases. The radial sagittal refractive power profile traversing the surface from the inner edge of the first annular portion (i.e., the edge closest to the optical axis of the lens) to the outer edge of the first annular portion (i.e., the edge closest to the peripheral region) may be defined by a line with a positive slope of about 1.0 D / mm to about 20.0 D / mm, preferably about 1.0 D / mm to about 6.0 D / mm, or by a curve with an average positive slope of about 1.0 D / mm to about 20.0 D / mm, preferably about 1.0 D / mm to about 6.0 D / mm (the average is obtained along the length of the curve).

[0079] For the surface of the first annular portion having a center of curvature at a first distance from the optical axis, the radial sagittal refractive power at the inner edge of the first annular portion (i.e., the edge closest to the central portion) may be 0.1D to 5.0D smaller than the radial sagittal refractive power at the outer edge of the central portion, and preferably about 0.5D to about 2.5D smaller than the radial sagittal refractive power at the outer edge of the central portion.

[0080] For the surface of the first annular portion having a center of curvature at a first distance from the optical axis, the radial sagittal refractive power at the outermost edge of the first annular portion (i.e., the edge closest to the peripheral region) may be 0.1D to 5.0D greater than the radial sagittal refractive power at the outer edge of the central portion, preferably 0.5D to 2.0D greater.

[0081] The radial sagittal refractive power profile of the first annulus, as a whole, provides additional radial sagittal refractive power over the radial width of the first annulus and has a radial sagittal refractive power profile that increases with increasing radial distance from the optical axis. The radial sagittal refractive power profile of the first annulus, from the inner edge of the first annulus (i.e., the edge closest to the optical axis of the lens) to the outer edge of the first annulus (i.e., the edge closest to the peripheral region), can be defined as a line with a positive slope of about 0.5 D / mm to about 20.0 D / mm, preferably about 0.5 D / mm to about 5.0 D / mm, or a curve with an average positive slope of about 0.5 D / mm to about 20.0 D / mm, preferably about 0.5 D / mm to about 5.0 D / mm (the average is obtained along the length of the curve).

[0082] As described above, the surface of a first annular portion having a center of curvature on the optical axis provides a radial sagittal additional refractive power, which may be substantially constant over the radial width of the surface. The surface of a first annular portion having a center of curvature at a distance of first from the optical axis has a radial sagittal refractive power profile that increases with increasing radial distance from the optical axis. The surface of a first annular portion having a center of curvature at a distance of first from the optical axis may have an average radial sagittal additional refractive power of zero over the radial width of the surface, or it may provide a radial sagittal additional refractive power.

[0083] The radial sagittal refractive power across the first annular portion of the lens may be less than the radial curvature refractive power across the first annular portion of the lens. The first annular portion as a whole has an average radial sagittal additional refractive power between +0.5 and +6.0D, preferably between +2.0D and +4.0D, or between +0.5 and +2.0D. The first annular portion as a whole has an average radial curvature refractive power between +4.0 and +24.0D, preferably between +4.0D and +12.0D. The radial curvature refractive power may be approximately constant across the entire radial width of the first annular portion.

[0084] The lens may comprise at least one additional annular portion concentric with the first annular portion. Each additional annular portion, or any of the additional annular portions, may have any of the features of the first annular portion described above. Similar to the first annular portion, each additional annular portion, or any of the additional annular portions, may provide additional radial curvature refractive power, the radial curvature refractive power of the additional annular portion being the sum of the radial curvature refractive power of the front surface of the additional annular portion and the radial curvature refractive power of the rear surface of the additional annular portion. The additional radial curvature refractive power of each additional annular portion may be between +0.0D and +24.0D, preferably between +4.0D and +12.0D.

[0085] For each additional annular section or any additional annular section, the radial curvature refractive force of one of the front and rear surfaces of the additional annular section may provide a first radial curvature additional refractive force, and the other front and rear surface of the additional annular section may provide a second, different radial curvature additional refractive force. Alternatively, for each additional annular section or any additional annular section, the front and rear surfaces of the additional annular section may provide the same radial curvature additional refractive force.

[0086] For each additional annular section, or any additional annular section, either the front or rear surface of the additional annular section may have a center of curvature on the optical axis. The surface may have a radial sagittal refractive power greater than the radial sagittal refractive power of the central part of the lens (i.e., the surface may provide a radial sagittal additional refractive power). This radial sagittal additional refractive power may be substantially constant over the radial width of the surface.

[0087] For each additional annular section, or any additional annular section, the front and rear surfaces of the additional annular section may have a center of curvature at a certain distance from the optical axis and may be radially inclined with respect to the central section. As a result of this inclination, the surface of each additional annular section, or any additional annular section, having a center of curvature at a certain distance from the optical axis, may have a radial sagittal refractive power profile that increases with increasing radial distance from the optical axis. The gradient of the radial sagittal refractive power profile across the surface may be about 1.0 D / mm to about 20.0 D / mm, preferably about 1.0 D / mm to about 4.0 D / mm. The degree of inclination may be selected such that the radial sagittal refractive power at a point halfway across the radial width of the surface is equal to the average radial sagittal refractive power at the central section of the lens.

[0088] For each additional annular section, or any additional annular section, the radially inclined surface may be inclined with respect to the central section by the same amount as the first annular section, or by a different amount. When the surface of an annular section is inclined with respect to the central section, the center of curvature of that surface is shifted away from the optical axis. The center of curvature of each additional annular section, or any additional annular section, may be shifted away from the optical axis by the same first distance as the center of curvature of the first annular section. Alternatively, the center of curvature of each additional annular section, or any additional annular section, may be shifted away from the optical axis by a different distance from the center of curvature of the first annular section.

[0089] The radial sagittal refractive power profile of each additional annular section or any additional annular section may depend on the radial position of the annular section. Annular sections at greater radial distances from the optical axis may have a larger or smaller radial sagittal refractive power gradient compared to the first annular section. The first annular section may have a radial sagittal refractive power profile that increases according to a first gradient as the radial distance from the optical axis increases, and the second annular section may have a radial sagittal refractive power profile that increases according to a second gradient smaller than the first gradient as the radial distance from the optical axis increases. The first gradient is about 0.5 D / mm to about 20.0 D / mm, preferably about 0.5 D / mm to about 5.0 D / mm. The second gradient is about 0.5 D / mm to about 20.0 D / mm, preferably about 0.5 D / mm to about 3.0 D / mm.

[0090] In comparison between the first annular portion and each additional annular portion or any additional annular portion, the radial curvature refractive power of the lens (of the latter) may be less than the radial curvature refractive power of the first annular portion. The region of the lens between multiple concentric annular portions may hereafter be referred to as the distance refractive power portion. The lens may comprise multiple concentric additional annular portions, which may be separated by a distance portion having a radial curvature refractive power of the base.

[0091] Contact lenses can be toric contact lenses. For example, toric contact lenses may include an optical zone that is shaped to correct a person's astigmatism.

[0092] Contact lenses may include elastomer materials, silicone elastomer materials, hydrogel materials, or silicone hydrogel materials, or combinations thereof. As understood in the field of contact lenses, a hydrogel is a material that maintains water in equilibrium and does not contain silicone-containing compounds. A silicone hydrogel is a hydrogel that contains silicone-containing compounds. As described in the context of this disclosure, hydrogel materials and silicone hydrogel materials have an equilibrium water content (EWC) of at least 10% to about 90% (wt / wt). In some embodiments, the hydrogel material or silicone hydrogel material has an EWC of about 30% to about 70% (wt / wt). In comparison, as described in the context of this disclosure, silicone elastomer materials have a water content of about 0% to less than 10% (wt / wt). Typically, the silicone elastomer materials used in the Method or Apparatus have a water content of 0.1% to 3% (wt / wt).Examples of suitable lens formulations (compositions) include those with the following US generic names (USAN): metafilcon A, ocufilcon A, ocufilcon B, ocufilcon C, ocufilcon D, omafilcon A, omafilcon B, comfilcon A, enfilcon A, stenfilcon A, fanfilcon A, etafilcon A, cenophil 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.

[0093] For example, the lens may comprise a hydrogel contact lens or a silicone hydrogel contact lens having a lens diameter of 13mm to 15mm.

[0094] According to a second aspect, the present disclosure provides a method for manufacturing a contact lens, comprising the step of forming a contact lens, the contact lens comprising an optical zone, the optical zone comprising a central portion having a center of curvature on the optical axis, and a first annular portion extending radially outward from the central region, the first annular portion providing radial curvature additional refractive power, one of the front and rear surfaces of the first annular portion having a center of curvature on the optical axis, and the other of the front and rear surfaces of the first annular portion having a center of curvature at a first distance from the optical axis.

[0095] The lens may include any of the features described above in relation to the first embodiment.

[0096] A method for manufacturing the lens may include a step of tilting one annular portion of the lens surface relative to the central portion so that the center of curvature of the surface is separated from the optical axis by a first distance. In practice, this tilting step may include a step of incorporating the tilt into the optical design of the front or rear surface of the first annular portion of the lens.

[0097] The manufacturing method may include the step of providing a female mold member having a concave lens forming surface and a male mold member having a convex lens forming surface. One of the concave lens forming surface and the convex lens forming surface is configured to produce the surface of a first annular portion having a center of curvature at a first distance from the optical axis of the lens. The surface will be radially inclined with respect to the central portion. The other of the concave lens forming surface and the convex lens forming surface is configured to produce the surface of a first annular portion having a center of curvature on the optical axis of the lens. The method may include the step of forming a lens using the female mold member and the male mold member. The method may include the step of filling the gap between the female mold member and the male mold member with bulk lens material. The method may further include the step of curing the bulk lens material to form a lens.

[0098] The method may include a step of casting a contact lens by causing polymerization of the contact lens compound placed between the female and male mold members of a contact lens molding assembly. Alternatively, the method may include a step of turning the surface of the contact lens. For example, one or both surfaces of the contact lens may be machined using a lathe to provide desired optical properties.

[0099] Contact lenses can be molded contact lenses. Lenses can be formed by a casting process, a spin-casting process, a turning process, or a combination thereof. As understood by those skilled in the art, casting refers to the process of forming a lens by placing lens forming material between a female mold having a concave lens forming surface and a male mold having a convex lens forming surface.

[0100] A third aspect of this disclosure provides a method of using the contact lenses described herein. This method may be effective in suppressing the progression of refractive error abnormalities, such as the progression of myopia. When the lenses of the present invention are used to suppress the progression of myopia, the method may include the step of providing the contact lenses to a person whose eyes can adjust (adapt) to a range of near distances (e.g., in the range of about 15 cm to about 40 cm). Some embodiments of the method include the step of providing ophthalmic lenses to a person who is about 5 to about 25 years old. This providing step may be performed by an ophthalmologist, such as an optician or optometrist. Alternatively, this providing step may be performed by a lens distributor who arranges delivery of the ophthalmic lenses to the lens wearer.

[0101] Figure 1A shows a schematic plan view of the lens surface 1 of a contact lens according to one embodiment of the present disclosure. In some embodiments of the contact lens of the present disclosure, this lens surface 1 may be the front or rear surface of the contact lens. Figure 1B shows a schematic side view of the lens surface 1 of Figure 1A. The lens surface 1 comprises an optical zone 2 that generally covers the pupil and a peripheral zone 4 located above the iris. The peripheral zone 4 provides mechanical functions, including increasing the size of the contact lens to make it easier to handle, providing ballast to prevent rotation of the contact lens, and providing a shape area that improves the comfort of the contact lens wearer. The optical zone 2 provides optical functions, and the optical zone 2 includes an annular region 3 and a central region 5. The contact lens has a radial curvature refractive power of the base, which is equal to the radial sagittal refractive power of the base. The refractive power of the base results from the radius of curvature of the central region 5. The center of curvature of the central region 5 is on the first optical axis 19 (shown in Figure 2A). The annular region 3 has a radial curvature refractive power greater than that of the base. The radial curvature refractive power of the annular region 3 is provided by the radius of curvature 6 of the annular region 3, which is smaller than the radius of curvature 7 of the central region 5, as shown in Figure 3. The center of curvature of the annular region 3 lies on the first optical axis 19. The annular region 3 has a greater refractive power than the central region 5. As shown in Figure 2A, 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. The focal point 11 of the annular region 3 is on the proximal focal plane 13, and the focal point of the central region 5 is on the distal focal plane 17, which is further away from the rear surface of the lens. As shown in Figure 2C, for a point source at infinity, the rays focused by the central region 5 form a focused image 23 at the distal focal plane 17. The rays focused by the central region 5 also produce out-of-focus blur spots 27 at the proximal focal plane 13.

[0102] As shown in Figure 2B, the rays focused by the annular region 3 form a focal image 21 at the proximal focal plane 13. The rays focused by the annular region 3 diverge after the proximal focal plane 13, and these diverging rays produce an out-of-focus annular (ring-shaped) image 25 at the distal focal plane 17. As mentioned above, the out-of-focus annular image 25 can result in a wearer of a contact lens having such a lens surface 1 seeing a "halo" around the focused distant image.

[0103] Figure 4A is a plot (graph) 31 showing the change in sagittal refractive power in the radial direction of the lens surface 1 shown in Figures 1A and 1B, and Figure 4B is a plot (graph) 33 showing the change in curvature refractive power in the radial direction of the lens surface 1 shown in Figures 1A and 1B. Figures 4A and 4B show the change in refractive power along the radial diameter of the lens surface 1. In the case of this lens surface 1, the annular region 3 has an on-axial curvature center and provides additional sagittal refractive power in the radial direction, so the sagittal refractive power in the radial direction (shown by curve 35) is greater over the annular region 3 than over the central region 5, and the sagittal refractive power in the radial direction is approximately constant over the radial width of the annular region 3. The curvature refractive power in the radial direction (shown by curve 37) is also greater over the annular region 3 than over the central region 5, and the curvature refractive power in the radial direction is approximately constant over the radial width of the annular region 3.

[0104] Figure 5A shows a schematic plan view of another lens surface 101 of a contact lens according to some embodiments of the present disclosure, the lens surface 101 having a non-coaxial optical system. In some embodiments of the contact lens according to the present disclosure, this lens surface 101 may be the front or rear surface of the contact lens 101. Figure 5B is a schematic side view of the lens surface 101 of Figure 5A. Similar to lens surface 1 of Figure 1A, the lens surface 101 comprises an optical zone 102 that generally covers the pupil and a peripheral zone 104 located above the iris. The peripheral zone 104 provides mechanical functions, including increasing the size of the contact lens to make the lens 101 easier to handle, providing ballast to prevent rotation of the contact lens 101, and providing a shape region that improves the wearer's comfort of the contact lens 101. The optical zone 102 provides optical functions, and the optical zone 102 includes an annular region 103 and a central region 105. The lens surface 101 has a base radial curvature refractive power, which is equal to the base radial sagittal refractive power. The refractive power of the base results from the radius of curvature of the lens surface 101. The center of curvature of the central region 105 lies on the first optical axis 119 (shown in Figure 6A). The annular region 103 has a radial curvature refractive power greater than the base radial curvature refractive power. The radial curvature refractive power of the annular region 103 is provided by the radius of curvature of the annular region 103, which is smaller than the radius of curvature of the central region 105. However, in contrast to the lens surface 1 in Figure 1A, in the case of the lens 101 shown in Figures 5A and 5B, the curvature of the annular region 103 cannot be defined by a single sphere, and the center of curvature of the annular region 103 does not lie on the first optical axis 119. This is shown in Figure 6D. The annular region 103 is inclined with respect to the central region 105, and the outer edge of the annular region 103 is higher than its inner edge than in the case of lens surface 1 in Figures 1A and 1B (see Figure 5B). This changes the radial sagittal refractive power of the annular region 103, but does not change the radial curvature refractive power of the annular region 103. As shown in Figure 6D, the central region 105 defines a portion of the surface of a larger radius sphere 107. The annular region 103 defines a curved annular surface 106 with a smaller radius.

[0105] At the distal focal plane 117, the light rays passing through the central region 105 are focused (converged). The annular region 103 acts as an optical beam stop, which results in a small spot size 133 of light 124 at the distal focal plane 117, as shown in Figure 6C.

[0106] No single image is formed at the proximal focal plane 113. As shown in Figure 6B, at the proximal focal plane 113, for a point source at infinity, rays passing through the central region 105 produce a blur circle 128, similar to the lenses in Figures 1A and 1B and 2A and 2B. On the other hand, rays from a distant point source passing through the annular region 103 produce a focused ring 122, which surrounds the blur circle 128, as shown in Figure 6B. Figure 6B shows the light pattern produced for a distant point source. In contrast to lens surface 1 in Figures 1A and 1B, lens surface 101 in Figures 5A and 5B does not produce a single image or an axial image at the proximal focal plane 113, which could be used to avoid the need for the eye to adapt to a proximal object. For a distant augmented object, the focal image formed at the proximal focal plane 113 is a convolution of (i) the focal image of the augmented object that would be obtained with a conventional lens having the refractive power of the annular region 103, and (ii) an optical transfer function representing the optical effect of the annular region 103.

[0107] In contrast to the lenses in Figures 1A and 1B, the annular or "halo" effect does not occur at the distal focal plane 117.

[0108] Figure 7A is a plot (graph) 131 showing the change in sagittal refractive power in the radial direction of the lens surface 101 shown in Figures 5A and 5B. Figure 7B is a plot (graph) 133 showing the change in radial curvature refractive power of the lens 101 shown in Figures 5A and 5B. Figures 7A and 7B show the change in refractive power along the radial diameter of the lens surface 101. In the case of this lens 101, the annular region 103 provides additional radial curvature refractive power, and the radial curvature refractive power (shown by curve 137) is greater across the annular region 103 than across the central region 105. However, the annular region 103 is tilted relative to the central region 105, and the annular region 103 has an off-axis curvature center. The inclination of the annular region 103 relative to the central region 105 means that, as shown by curve 135, the radial sagittal refractive force at the boundary between the central region 105 and the annular region 103 is even more negative than the radial sagittal refractive force of the central region. The radial sagittal refractive force may increase with increasing radial distance toward the outer edge of the annular region 103.

[0109] In some embodiments of the present disclosure, the contact lens comprises an optical zone, the optical zone including a central portion having a center of curvature on the optical axis, and an annular portion extending radially outward from the central portion. The lens has a front surface and a rear surface. One of the front and rear surfaces of the first annular portion has a center of curvature on the optical axis, and the other of the front and rear surfaces of the first annular portion has a center of curvature at a first distance from the optical axis.

[0110] In some embodiments of this disclosure, a lens surface having an annular region with a center of curvature on the optical axis may be a lens surface 1 as shown and described in Figures 1A to 4D.

[0111] A lens surface having an annular region with a center of curvature located at a first distance from the optical axis may be a lens surface 101 as shown and described in Figures 5A to 7D.

[0112] Figure 8A shows a schematic plan view of a contact lens 2001 according to one embodiment of the present disclosure. The lens 2001 includes a lens front (not shown), which is similar to lens surface 1 shown and described in Figures 1A to 4D. The lens 2001 also includes a lens rear (not shown), which is similar to lens surface 101 shown and described in Figures 5A to 7B. These lens front and rear surfaces are aligned to share a common optical axis 219.

[0113] The lens 2001 comprises an optical zone 202 that generally covers the pupil and a peripheral zone 204 located above the iris. The peripheral zone 204 provides mechanical functions, including increasing the size of the lens to make the lens 2001 easier to handle, providing ballast to prevent rotation of the lens 2001, and providing a shape region to improve the wearer's comfort of the lens 2001. The optical zone 202 provides the optical functions of the lens 2001, and the optical zone 202 includes an annular portion 203 and a central portion 205. The central portion 205 of the lens 2001 has a radial curvature refractive power of the base, which is equal to the radial sagittal refractive power of the base. In this exemplary embodiment of the present disclosure, the radial curvature refractive power of the base of the central portion is 0.0D, which is equal to the radial sagittal refractive power of the base of the central portion 205. The refractive power of this base is a consequence of the curvature of the front and rear surfaces of the lens 2001, and the radial curvature refractive power of the base of the central section 205 is the sum of the radial curvature refractive power of the front surface of the central section 205 and the radial curvature refractive power of the rear surface of the central section 205. The curvature center 244 of the central section 205 lies on the first optical axis 219 (shown in Figure 9). The annular section 203 has a radial curvature refractive power greater than the radial curvature refractive power of the base, i.e., the annular section 203 provides additional radial curvature refractive power. The radial curvature refractive power of the annular portion 203 is, as a whole, the result of the radius of curvature of the front surface of the annular portion 203 and the radius of curvature of the rear surface of the annular portion 203, and the radial curvature refractive power of the annular portion 203 is the sum of the radial curvature refractive power of the front surface of the annular portion 203 and the radial curvature refractive power of the rear surface of the annular portion 203. In this embodiment, the radial curvature refractive power of the rear surface of the lens is +2D, and the radial curvature refractive power of the front surface of the lens is +1.5D. At the distal focal plane 217, rays passing through the central region 205 are focused. Rays passing through the annular region 203 are guided toward the sagittal additional focal plane 218.

[0114] The front surface of the annular section 205 also provides an additional radial sagittal refractive force of approximately 2.0D. The radial sagittal refractive force profile is substantially constant across the radial width of the front surface of the annular section 205.

[0115] The rear surface of the annular section 203 is radially inclined with respect to the central section 205, so that the center of curvature 243 of the rear surface of the annular section 203 is offset from the first optical axis 219. This is shown in Figure 9. Inclining the rear surface of the annular section 203 with respect to the central section 205 reduces the radial sagittal refractive power at the boundary between the central section 205 and the annular section 203. Considering only the rear surface of the annular section 203, the average radial sagittal additional refractive power over the radial width of the annular section 203 is zero, and the radial sagittal refractive power over the radial width increases according to a linear gradient of 1 D / mm.

[0116] Figure 10A is a plot (graph) 231 showing the change in radial curvature refractive power over the radial diameter of lens 2001 shown in Figures 8A and 8B. This plot 231 shows the average radial and circumferential curvature refractive power of lens 2001 as a whole, which is the sum of the refractive power of the front and rear surfaces of the lens. Throughout the central portion 205, the curvature refractive power of lens 2001 is constant and approximately zero. At the boundary between the central portion 205 and the annular portion 203, the curvature refractive power shows a sharp increase, as shown by curve 235. This is due to the additional radial curvature refractive power of the front and rear surfaces of lens 2001. At the boundary between the central portion 205 and the annular portion 203, the circumferential curvature refractive force does not change significantly, but the radial curvature refractive force increases. Therefore, at this boundary with the central portion 205, the average curvature refractive force (shown by curve 235) increases to the average of the circumferential curvature refractive force and the radial curvature refractive force.

[0117] Figure 10B is a plot (graph) 233 showing the change in sagittal refractive power over the radial diameter of lens 2001 shown in Figures 8A and 8B. This plot 233 shows the average radial and circumferential sagittal refractive power of lens 2001 as a whole, which is the sum of the refractive power of the front and rear surfaces of the lens. Throughout the central portion 205 of lens 2001, the sagittal refractive power is constant and has a value of 0.0D. At the boundary between the central portion 205 and the annular portion 203, the sagittal refractive power of the annular portion 203 increases sharply, as shown by the curve 237. This is due to the additional radial sagittal refractive power at the front of the annular portion 203. The radial sagittal refractive power increases roughly linearly outward radially over the width of the annular portion 203 as a result of the radial inclination of the rear surface of the annular portion 203. The radial sagittal refractive power profile across the annular portion 203 is, as a whole, a combination of the radial sagittal additional refractive power on the front surface of the annular portion 203 (having a profile similar to the profile of lens surface 1 shown in Figure 4A) and the radial sagittal additional refractive power on the rear surface of the annular portion 203 (resulting in a profile similar to the profile of lens surface 101 shown in Figure 7A).

[0118] As shown in Figure 11A, in the case of the lens 2001 shown in Figures 8A and 8B, considering the lens as a whole (i.e., the front and rear surfaces of the lens 203), at the distal focal plane 217, rays passing through the central part 205 form a focused image 223, as shown in Figure 11B. Rays passing through the annular part 203 generate an out-of-focus ring 225 at the distal focal plane 217. As shown in Figure 11C, for a point light source at infinity, at the first proximal focal plane 218, rays passing through the central part 205 generate a first blurring circle 227, and rays passing through the annular part 203 generate a second blurring circle 229. As shown in Figure 11D, in the second proximal focal plane 220, rays passing through the central part 205 generate a third blurring circle 231, and rays passing through the annular part 203 generate a ring 233 focused within the third blurring circle 231.

[0119] In embodiments of the present disclosure shown and described in Figures 8A to 11D, the lens has one annular portion. In other embodiments (not shown), the lens has multiple concentric annular portions.

[0120] In the embodiments of the present disclosure shown and described in Figures 8A to 11D, the rear surface of the annular portion has a center of curvature located at a first distance from the optical axis of the lens, and the front surface of the annular portion has a center of curvature located on the optical axis of the lens. In other embodiments (not shown), the front and rear surfaces of the lens can be reversed such that the front surface of the annular portion has a center of curvature located at a first distance from the optical axis of the lens, and the rear surface of the annular portion has a center of curvature located on the optical axis of the lens.

[0121] In the embodiments of the present disclosure shown and described in Figures 8A to 11D, the rear surface of the annular portion is radially inclined with respect to the central portion, and the average radial sagittal refractive power over the radial width of the rear surface of the annular portion is zero. That is, on average, over the radial width, the rear surface of the annular portion does not provide additional radial sagittal refractive power. In other embodiments of the present disclosure (not shown), both the rear and front surfaces of the annular portion provide additional radial sagittal refractive power, and one of the rear or front surfaces of the annular region is radially inclined with respect to the central portion. In these embodiments, the radial sagittal refractive power over the width of the annular portion is the sum of the radial sagittal refractive power of the front surface of the annular portion and the radial sagittal refractive power of the rear surface of the annular portion.

[0122] Figure 12 is a flowchart showing a method for manufacturing an ophthalmic lens according to one embodiment of the present invention. In a first step 1001, a female mold member having a concave lens forming surface and a male mold member having a convex lens forming surface are provided. The concave lens forming surface is configured to generate a first annular portion of the lens having a curvature center at a first distance from the optical axis of the lens. The convex lens forming surface is configured to generate a first annular portion of the lens having a curvature center on the optical axis of the lens. In a second step 1003, the lens is cast using the male and female mold members. Step 1003 includes filling the gap between the female and male mold members with bulk lens material and curing the bulk lens material to form a lens. The lens comprises an optical zone. The optical zone includes a central region having a curvature center on the optical axis of the lens and a first annular portion extending radially outward from the central region. The first annular portion provides additional curvature refractive power. In this embodiment, the front surface of the annular section is manufactured using the lens-forming surface of a concave female mold member, and this front surface is configured to produce a first annular portion of a lens having a center of curvature at a first distance from the optical axis of the lens. The rear surface of the annular section is manufactured using the lens-forming surface of a convex male mold member, and this rear surface is configured to produce a first annular portion of a lens having a center of curvature on the optical axis of the lens. In other embodiments, the lens-forming surfaces of the female and male mold members may be reversed such that the concave lens-forming surface of the female mold member is configured to produce an annular portion of a lens having a center of curvature on the optical axis of the lens, and the convex lens-forming surface of the male mold member is configured to produce an annular portion of a lens having a center of curvature at a first distance from the optical axis of the lens. In this case, the front surface of the annular portion will have a center of curvature on the optical axis of the lens, and the rear surface of the annular portion will have a center of curvature at a first distance from the optical axis of the lens.

[0123] The preceding description refers to integers or elements that have known, obvious, or predictable equivalents, but such equivalents are incorporated herein as if they were described separately. Reference to the claims should be made to determine the true scope of this disclosure. The claims should be interpreted as encompassing all such equivalents. Readers will also understand that integers or features of this disclosure described as advantageous or convenient are optional and do not limit the scope of the independent claims. Furthermore, it should be understood that such optional integers or features may be beneficial in some embodiments of this disclosure but undesirable in others, and therefore may not be present in others.

Claims

1. A contact lens equipped with an optical zone, The optical zone is A central part having a center of curvature on the optical axis, The first annular portion extends radially outward from the central portion, Includes, The first annular portion provides additional refractive force due to radial curvature, One of the front and rear surfaces of the first annular portion has a center of curvature on the optical axis, The front and rear surfaces of the first annular portion have a center of curvature that is a first distance away from the optical axis. Contact lenses characterized by the following features.

2. The front surface of the first annular portion provides a first radial curvature additional refractive force, The rear surface of the first annular portion provides a second different radial curvature additional refractive force. The contact lens according to feature 1.

3. The surface of the first annular portion having a center of curvature on the optical axis provides additional refractive power of radial curvature from +0.5D to +4.0D. The surface of the first annular portion having a curvature center located at a first distance from the optical axis provides additional refractive power in the radial curvature range of +4.0D to +20.0D. A contact lens according to feature 1 or 2.

4. The surface of the first annular portion having a center of curvature located at a first distance from the optical axis has a radial sagittal refractive power profile that increases as the radial distance from the optical axis increases. A contact lens according to any one of features 1 to 3.

5. The surface of the first annular portion having a center of curvature at a first distance from the optical axis has a radial sagittal refractive power profile defined by a line with a gradient of 1.0 D / mm to 6.0 D / mm, or a curve with an average gradient of 1.0 D / mm to 6.0 D / mm. A contact lens according to any one of features 1 to 4.

6. The surface of the first annular portion having a center of curvature located at a first distance from the optical axis has an average radial sagittal additional refractive power of zero over the radial width of the first annular portion. A contact lens according to any one of features 1 to 5.

7. For the surface of the first annular portion having a center of curvature located at a first distance from the optical axis, the radial sagittal refractive power at the inner edge of the first annular portion is 0.5D to 2.5D smaller than the radial sagittal refractive power at the outer edge of the central portion. A contact lens according to any one of features 1 to 6.

8. For the surface of the first annular portion having a center of curvature located at a first distance from the optical axis, the radial sagittal refractive power at the outer edge of the first annular portion is 0.5D to 2.5D greater than the radial sagittal refractive power at the outer edge of the central portion. The contact lens according to feature 7.

9. Both the front and rear surfaces of the first annular portion provide a greater-than-zero radial sagittal additional refractive force over the radial width of the first annular portion. A contact lens according to any one of features 1 to 5.

10. The first annular portion has an average radial sagittal additional refractive power of +0.5D to +6.0D. A contact lens according to any one of features 1 to 9.

11. The first annular portion has a radial sagittal refractive power profile that increases as the radial distance from the optical axis increases. A contact lens according to any one of the features 1 to 10.

12. The first annular portion has a radial sagittal refractive power profile defined by a line having a gradient of 0.5 D / mm to 5.0 D / mm, or a curve having an average gradient of 0.5 D / mm to 5.0 D / mm. The contact lens according to feature 11.

13. The first annular portion has an average radial curvature refractive power of +4.5D to +24.0D. A contact lens according to any one of features 1 to 12.

14. at least one additional annular portion concentric with the first annular portion Equipped with, Each additional annular section provides additional refractive force due to radial curvature. For each additional ring section, One of the front and rear surfaces of the additional annular portion has a center of curvature on the optical axis, The other of the front and rear surfaces of the additional annular portion has a center of curvature that is a first distance away from the optical axis. A contact lens according to any one of features 1 to 13.

15. The radial sagittal refractive force gradient of each additional annular section depends on the radial position of that annular section. The contact lens according to feature 14.

16. The first annular portion has a radial sagittal refractive power profile that increases according to a first gradient as the radial distance from the optical axis increases. The second annular portion has a radial sagittal refractive power profile that increases according to a second gradient that is smaller than the first gradient as the radial distance from the optical axis increases. The contact lens according to feature 14 or 15.

17. Multiple concentric additional annular sections Equipped with, The plurality of additional annular portions are separated by distance portions having a base radial curvature refractive force. A contact lens according to any one of features 14 to 16.

18. The first annular portion extends radially outward by 0.5 mm to 1.5 mm from the periphery of the central portion. A contact lens according to any one of features 1 to 17.

19. The lens includes an elastomer material, a silicone elastomer material, a hydrogel material, a silicone hydrogel material, or a mixture thereof. A contact lens according to any one of features 1 to 18.

20. A method for manufacturing a contact lens according to any one of claims 1 to 19, The process of forming contact lenses Equipped with, The contact lens has an optical zone, The optical zone is A central part having a center of curvature on the optical axis, The first annular portion extends radially outward from the central portion, Includes, The first annular portion provides additional refractive force due to radial curvature, One of the front and rear surfaces of the first annular portion has a center of curvature on the optical axis, The front and rear surfaces of the first annular portion have a center of curvature that is a first distance away from the optical axis. A method characterized by the following:

21. A step of providing a female mold member having a concave lens forming surface, A step of providing a male member having a convex lens forming surface, A step of forming the contact lens using the female member and the male member, Furthermore, The concave lens forming surface and the convex lens forming surface are configured to generate a first annular portion having a center of curvature located at a first distance from the optical axis of the contact lens. The other of the concave lens forming surface and the convex lens forming surface is configured to generate a first annular portion having a center of curvature on the optical axis of the contact lens. The method according to the present invention, characterized by the present invention.

22. A process of casting the contact lens using the male mold member and the female mold member. The method according to 21, further comprising the following:

23. A method to suppress the progression of myopia, A process to provide a contact lens according to any one of claims 1 to 19 to a person with myopia who can adapt to changing near distances. A method characterized by comprising:

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