Contact lenses and methods related thereto

Abstract

The invention relates to contact lenses and methods related thereto. A contact lens (201) and a method of making such a lens are described. The lens (201) comprises an optical region (202). The optical region (202) includes a central region (205) having a first optical axis (219), a substantially radial curvature power, a substantially radial sagittal power, and a center of curvature on the first optical axis (219). The optical region (202) comprises an annular region (203), where the annular region (203) has a radial curvature refractive power of X at a point across half a width of the annular region (203), where X is greater than the substantially radial curvature refractive power. The annular region (203) has an off-axis center of curvature at a first distance from the optical axis (219) such that, at a point across half its width, the annular region (203) has a sagittal power of Y, where Y is greater than the substantially radial sagittal power, and where Y is less than X.

Description

[0001] Information about divisional applications

[0002] This case is a divisional application. The parent case of the divisional application is an invention patent application with an application date of December 15, 2022, application number 202280080627.5, and invention name "Contact lenses and methods related thereto". Technical Field

[0003] The present invention relates to contact lenses. The present invention particularly (but not exclusively) relates to contact lenses for slowing the progression of myopia. The present invention also particularly (but not exclusively) relates to contact lenses for use by presbyopes. The present invention also relates to methods of making such lenses. Background Art

[0004] Many people (including children and adults) need contact lenses to correct myopia (short-sightedness) and many adults may need lenses to correct presbyopia (the age-related inability to accommodate and therefore focus on close objects).

[0005] Myopic eyes focus incident light from distant objects to a position in front of the retina. Therefore, the light converges and diverges toward a plane in front of the retina and is out of focus when it reaches the retina. Conventional lenses (e.g., spectacle lenses and contact lenses) used to correct myopia reduce the convergence of incident light from distant objects before it reaches the eye (for contact lenses), or cause it to diverge (for spectacle lenses), so that the focal position is shifted onto the retina.

[0006] Presbyopia is the inability of a person with presbyopia to focus on near objects because the lens does not change shape effectively to accommodate near objects. Conventional lenses (e.g., spectacle lenses and contact lenses) used to correct presbyopia include bifocal or progressive lenses that include a zone optimized for near vision and a zone optimized for distance vision. Presbyopia can also be treated using bifocal or multifocal lenses or single vision lenses (where a different prescription is provided for each eye, one eye is equipped with a distance vision lens, and one eye is equipped with a near vision lens).

[0007] Decades ago it was suggested that the progression of myopia in children or young adults could be slowed or prevented by undercorrection, i.e., moving the focus toward the retina but not completely on the retina. However, such an approach necessarily results in a reduction in distance vision compared to the vision obtained with a lens that fully corrects myopia. Furthermore, it is now doubtful that undercorrection is effective in controlling developing myopia. A more recent approach to correcting myopia is to provide a lens with both one or more zones of full correction that provide distance vision and one or more zones of undercorrection or intentionally induced myopic defocus. It has been suggested that this approach could prevent or slow the development or progression of myopia in children or young adults while providing good distance vision.

[0008] In the case of lenses with zones that provide defocus, the zone that provides full correction for distance vision is often referred to as the base power zone and the zone that provides undercorrection or intentionally induced myopic defocus is often referred to as the myopic defocus zone or add power zone (because the refractive power is more positive or less negative than the power of the distance vision zone). The surface (usually the front surface) of the add power zone has a smaller radius of curvature than the distance vision zone and therefore provides a more positive or less negative refractive power to the eye. The add power zone is designed to focus incident parallel light (i.e., light from a distance) in front of the retina (i.e., closer to the lens) in the eye, while the distance vision zone is designed to focus light and form an image at the retina (i.e., farther from the lens).

[0009] One known type of contact lens that reduces the progression of myopia is a bifocal contact lens sold under the name MISIGHT (CooperVision, Inc.). This bifocal lens is different from bifocal or multifocal contact lenses configured to improve vision for presbyopes because the bifocal lens is configured with specific optical dimensions so that an adaptable person can view both distant and near objects using the hyperopic correction (i.e., base power). The treatment area of ​​the bifocal lens with added power also provides a myopic defocused image at both far and near viewing distances.

[0010] While these lenses have been found to be beneficial in preventing or slowing the development or progression of myopia, the annular add power zone can cause unwanted visual side effects. Light focused by the annular add power zone in front of the retina diverges from the focal point to form a defocused ring at the retina. As a result, wearers of these lenses may see a ring or "halo" surrounding the image formed on the retina, particularly for small, bright objects such as street lamps and car headlights. Furthermore, in theory, the wearer could utilize the additional focal point in front of the retina created by the annular add power zone to focus on near objects, rather than using the eye's natural accommodation (i.e., the eye's instinct to change focus) to focus on near objects; in other words, the wearer could inadvertently use the lens in the same manner as a presbyopia correction lens, which is undesirable for young subjects.

[0011] Further lenses have been developed that can be used to treat myopia and are designed to eliminate the halos observed around focused distance vision images in the MISIGHT (CooperVision, Inc.) lenses and other similar lenses described above. In these lenses, the annular zone is configured so that a single on-axis image is not formed in front of the retina, thereby preventing this image from being used to avoid the eye's accommodation of near objects as is required. Specifically, a point source of distant light is imaged through the annular zone to an annular focal line at the near add power focal plane, resulting in a small spot size of light at the distance focal plane without a surrounding "halo" effect on the retina.

[0012] To treat myopia, it is recognized that it may be beneficial to provide a lens that introduces additional myopic defocus. To treat presbyopia, it may be beneficial to provide a lens that produces an extended depth of focus. Summary of the invention

[0013] According to a first aspect, the present disclosure provides a contact lens comprising an optical zone. The optical zone includes a central zone having a first optical axis, a basic radial curvature power, and a basic radial sagittal power. The central zone has a center of curvature on the first optical axis. The optical zone includes an annular zone, wherein at a point halfway across the annular zone, the annular zone has a radial curvature power of X, wherein X is greater than the basic radial curvature power. The annular zone has an off-axis center of curvature at a first distance from the optical axis. At a point halfway across its width, the annular zone has a radial sagittal power of Y, wherein Y is greater than the basic radial sagittal power, and wherein Y is less than X.

[0014] According to a second aspect, the present disclosure provides a method of manufacturing a lens. The method comprises forming a contact lens according to the first aspect of the present invention.

[0015] It will of course be appreciated that features described with respect 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which:

[0017] Figure 1A is a schematic top view of a contact lens using a treatment zone that provides a myopic defocused image to reduce progression of myopia;

[0018] Figure 1B yes Figure 1A Side view of a contact lens;

[0019] Figure 2A yes Figure 1ARay diagram of the lens;

[0020] Figure 2B Displays the formation of distant point sources Figure 1A The light pattern at the proximal focal plane of the lens;

[0021] Figure 2C Displays the formation of distant point sources Figure 1A The light pattern at the distal focal plane of the lens;

[0022] Figure 3 yes Figure 1A and 1B A partial ray diagram of a lens and circles indicating the radii of curvature of the central distance vision zone (dash-dotted line) and the annular addition zone (dashed line) of the contact lens;

[0023] Figure 4A It is a display Figure 1A and 1B A plot of the variation of the sagittal-sagittal power of a lens shown in FIG.

[0024] Figure 4B It is a display Figure 1A and 1B A plot of the variation in radial curvature power of a lens shown in FIG.

[0025] Figure 5A is a top view of different contact lenses with non-coaxial optics;

[0026] Figure 5B yes Figure 5A Side view of a contact lens;

[0027] Fig. 6A yes Figure 5A and 5B Ray diagram of the lens;

[0028] Figure 6B Displays the formation of distant point sources Figure 5A and 5B The light pattern at the proximal focal plane of the lens;

[0029] Figure 6C Displays the formation of distant point sources Figure 5A and 5B The light pattern at the distal focal plane of the lens;

[0030] Fig.6D yes Figure 5A and 5B A partial ray diagram of a lens and circles indicating the radii of curvature of the central distance vision zone (dash-dotted line) and the annular addition zone (dashed line) of the contact lens;

[0031] Fig. 7A It is a display Figure 5A and 5B A plot of the variation of the sagittal-sagittal power of a lens shown in FIG.

[0032] Figure 7B It is a display Figure 5A and 5B A plot of the variation in radial curvature power of a lens shown in FIG.

[0033] Fig. 8A is a top view of a lens according to an embodiment of the present disclosure;

[0034] Figure 8B yes Fig. 8A Side view of a contact lens;

[0035] Fig. 9 yes Fig. 8A and 8B A partial ray diagram of a lens and circles indicating the radii of curvature of the central distance vision zone (dash-dotted line) and the annular addition zone (dashed line) of the contact lens;

[0036] Fig. 10A It is a display Fig. 8A and 8B A plot of the variation in radial curvature power of a lens shown in FIG.

[0037] Fig. 10B It is a display Fig. 8A and 8B A plot of the variation of the sagittal-sagittal power of a lens shown in FIG.

[0038] Fig.11A yes Fig. 8A and 8B Ray diagram of the lens;

[0039] Fig. 11B Displays the formation of distant point sources Fig. 8A and 8B The light pattern at the distal focal plane of the lens;

[0040] Fig. 11C Displays the formation of distant point sources Fig. 8A and 8B a light pattern at a first proximal focal plane of the lens;

[0041] Fig.11D Displays the formation of distant point sources Fig. 8A and 8B a light pattern at a second proximal focal plane of the lens;

[0042] Fig. 12A is a top view of a lens according to an embodiment of the present disclosure having a variation in radial curvature power;

[0043] Fig. 12B yes Fig. 12A Side view of a contact lens;

[0044] Fig.13A It was intercepted along line EE Fig. 12A and 12B Schematic diagram of a lens and circles indicating the radii of curvature of the central distance vision zone (dotted line) and the annular addition zone (dashed line) of the contact lens;

[0045] Fig. 13B It was taken along line FF Fig. 12A and 12B Schematic diagram of a lens and circles indicating the radii of curvature of the central distance vision zone (dotted line) and the annular addition zone (dashed line) of the contact lens;

[0046] Fig.14 It is a display Fig. 12A and 12B Schematic diagram of the radial curvature refractive power around the annular zone of the lens shown in FIG. 1 as a function of the sinusoidal variation of the angle θ;

[0047] Fig.15A is a schematic diagram showing sinusoidally varying refractive power around an annular zone of a lens according to an embodiment of the present disclosure with respect to an angle θ;

[0048] Fig. 15B is a schematic diagram showing the sawtooth variation refractive power around the annular zone of the lens according to an embodiment of the present disclosure with the angle θ;

[0049] Fig. 15C is a schematic diagram showing a square wave varying refractive power around an annular zone of a lens according to an embodiment of the present disclosure with an angle θ;

[0050] Fig.16 is a flow chart showing a method of designing a contact lens according to an embodiment of the present disclosure; and

[0051] Fig.17 Is used through Fig.16 Schematic diagram of radial cross-sections of a portion of three modeled lenses modeled using the method described herein. DETAILED DESCRIPTION

[0052] According to a first aspect, the present disclosure provides a contact lens. The lens includes an optical zone including a central zone, the central zone having a first optical axis, a basic radial curvature power and a basic radial sagittal power, and a center of curvature on the first optical axis. The central zone has an annular zone. At a point halfway across the width of the annular zone, the annular zone has a radial curvature power of X. X is greater than the basic radial curvature power. The annular zone has an off-axis center of curvature at a first distance from the optical axis, and such that at a point halfway across its width, the annular zone has a radial sagittal power of Y, wherein Y is greater than the basic radial sagittal power, and wherein Y is less than X.

[0053] As used herein, the term contact lens refers to an ophthalmic lens that can be placed on the front surface of the eye. It will be appreciated that such a contact lens will provide clinically acceptable on-eye mobility and will not stick 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 rests on the cornea of ​​the eye). The contact lens may be a soft contact lens, such as a hydrogel contact lens or a silicone hydrogel contact lens. The lens may be a lens for preventing or slowing the development or progression of myopia, which may be used to provide an extended depth of focus to a myopic eye.

[0054] Contact lenses according to the present disclosure include an optical zone. The optical zone covers the portion of the lens that has optical functionality. The optical zone is configured to be positioned above the pupil of the eye when in use. For contact lenses according to the present disclosure, the optical zone includes a central zone and an annular zone (or zones) surrounding the central zone. The optical zone is 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 it provides mechanical functions, for example, increasing the size of the lens, thereby making the lens easier to handle, providing ballast to prevent rotation of the lens, and / or providing a shaping zone that improves the comfort of the lens wearer. The peripheral zone may extend to the edge of the contact lens.

[0055] Contact lenses according to embodiments of the present disclosure may include ballast to orient the lens when the lens is positioned on the wearer's eye. Embodiments of the present disclosure that incorporate ballast into a contact lens will rotate to a predetermined repose angle under the action of the wearer's eyelid when placed on 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 contact lenses 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 is properly aligned with the astigmatism of the wearer's eye. It is possible that the contact lenses of the present disclosure provide a particular benefit to the wearer at a given orientation. For example, the contact lens may provide a particular benefit to the wearer when the meridian of maximum add power is in a particular orientation.

[0056] The contact lens can be generally circular in shape and have a diameter from about 4 mm to about 20 mm. The optical zone can be generally circular in shape and can have a diameter from about 2 mm to about 10 mm. In some embodiments, the contact lens has a diameter from 13 mm to 15 mm, and the optical zone has a diameter from 7 mm to 9 mm.

[0057] The first optical axis may be along the centerline of the lens. The central zone may focus light from a distant point object on the first optical axis to a point of light at a distal focal plane on the first optical axis. The term surface as used herein does not refer to a physical surface, but rather to a surface that can be drawn by points where light from a distant object will be focused. This surface is also referred to as an image plane (even though it may be a curved surface) or an image shell. The eye focuses light onto a curved retina, and in a perfectly focusing eye, the curvature of the image shell would match the curvature of the retina, so the eye would not focus light onto a flat mathematical plane. However, in the art, the curved surface of the retina is often referred to as a plane.

[0058] The central region may be generally circular in shape and may have a diameter between about 2 mm and 9 mm, and preferably between 2 mm and 7 mm. The central region may be generally elliptical in shape. The annular region may extend radially outward from the periphery of the central region by between about 0.1 mm and 4 mm, preferably between about 0.5 mm and 1.5 mm. For example, the radial width of the annular region may be between about 0.1 mm and about 4 mm, and preferably between about 0.5 mm and about 1.5 mm. The periphery of the central region may define a boundary between the central region and the annular region, and thus the annular region may be adjacent to the central region.

[0059] The annular zone may be adjacent to the central zone. A mixing zone may be provided between the central zone and the annular zone. The mixing zone should not substantially affect the optics provided by the central zone and the annular zone, and the mixing zone may have a radial width of 0.05 mm or less, but it may also be as wide as 0.2 mm, or in some embodiments as wide as 0.5 mm.

[0060] In the context of the present disclosure, the refractive powers of the central and annular zones of the lens may be defined as radial curvature power, circumferential curvature power, mean curvature power (which is the average of the radial and circumferential curvature powers), radial sagittal power, circumferential sagittal power and mean sagittal power (which is the average of the radial and circumferential sagittal powers).

[0061] The curvature and sagittal power are defined as follows:

[0062] For a wavefront W, at a point at a radial distance r (the pupil radius) from a line normal to the center of the wavefront, W(r) = A*r 2 , where A is a function.

[0063] Wavefront curvature or curvature refractive power Pc It is a function of the second derivative of the wavefront. Wavefront slope or slope-based refractive power P S It is a function of the first derivative of the wavefront and varies with the slope of the wavefront.

[0064] For a simple spherical lens, the curvature power P c is defined as:

[0065]

[0066] Refractive power P based on slope S is defined as

[0067]

[0068] That is, for a simple lens (with the paraxial assumption), P C =P S .

[0069] The radial curvature power is the curvature power in a direction extending radially outward from the center of curvature of the lens. The circumferential curvature power is the curvature power at a constant radial coordinate, extending around the circumference of the lens. The mean curvature provides the average of the radial and circumferential curvature powers.

[0070] Radial sagittal power is the sagittal power in a direction extending radially outward from the center of the lens. Circumferential sagittal power is the sagittal power at a constant radial coordinate, extending around the circumference of the lens.

[0071] The central zone may have a curvature power that is the same as the sagittal power. This is referred to herein as the base curvature power, base sagittal power, or base power. The nominal power of the central zone will correspond to the labeled power of the contact lens as provided on the contact lens packaging (but in reality it may not have the same value). This will be the average sagittal or average curvature power taken across the central zone. The measured power of the central zone is the directly measured average refractive curvature or sagittal power taken across the central zone. This may be different from the nominal power.

[0072] For lenses used in myopia treatment, the base power will be negative or close to zero, and the central zone will correct distance vision. The base power may be between 0.5 diopters (D) and -15.0 diopters. The base power may be from -0.25D to -15.0D.

[0073] The basic refractive power of the central zone may be generated by the curvature of the surface of the lens. The basic refractive power may be generated by the curvature of the front surface of the lens and / or the center of curvature of the back surface of the lens.

[0074] In the context of the present disclosure, an annular zone is a generally annular zone surrounding the optical zone. It may have a generally circular shape or a generally elliptical shape. It may completely surround the optical zone. It may partially surround the optical zone.

[0075] For the embodiments of the present disclosure, the radial curvature power of the annular zone is greater than the basic radial curvature power of the central zone.

[0076] The radial curvature power of the annular zone may be determined by the curvature of at least one surface of the annular zone. The radial curvature power of the annular zone may be generated by the curvature of the front surface and / or the back surface of the lens. The annular zone may have a larger curvature or a smaller radius of curvature than the central zone. The front surface of the annular zone may have a larger curvature or a smaller radius of curvature than the curvature of the central zone. Alternatively or additionally, the back surface of the annular zone may have a curvature greater than the curvature of the central zone.

[0077] The radial curvature power may vary across the annular zone. At a point halfway across the width of the annular zone, the radial curvature power of the annular zone is X. The radial curvature power will be a power that is more positive (or less negative) than the base radial curvature power. The net radial curvature power of the annular zone will be the sum of the base radial curvature power of the central zone and the radial curvature add power of the annular zone. For example, if the base radial curvature power is -3.0D and the radial curvature add power of the annular zone is +4.0D, then the net radial curvature power of the annular zone will be +1.0D.

[0078] The value of X may be between +0.5D and +20.0D. The value of X may be +10.0D greater than the base radial curvature power (i.e., the radial curvature add power at a point halfway across the width of the annular zone may be +10.0D). The value of X may be +11.0D greater than the base radial curvature power (i.e., the radial curvature add power at a point halfway across the width of the annular zone may be +11.0D). The value of X may be +12.0D greater than the base radial curvature power (i.e., the radial curvature add power at a point halfway across the width of the annular zone may be +12.0D).

[0079] The annular zone can be understood to be tilted relative to the central zone. As used herein, the tilt of the annular zone means a circular symmetrical tilt rather than a lateral tilt. The annular zone is tilted around a curve extending around the circumference of the lens so that the outer edge of the annular zone moves in a first direction and the inner edge of the annular zone moves in the opposite direction. Tilting the annular zone will change the radial sagittal power of the annular zone because this is a function of the first derivative of the wavefront, but will not change the radial curvature power of the annular zone, which is a function of the second derivative of the wavefront. Tilting the annular zone relative to the central zone will mean that the center of curvature of the annular zone is shifted away from the first optical axis of the central zone by a first distance. The radial sagittal power of the annular zone may span the width of the annular zone and vary in the embodiments of the present disclosure. At a point halfway across the width of the annular zone, the radial sagittal power of the annular zone is Y. Y will be greater than the basic radial sagittal power of the central zone, but Y will be less than X (the radial curvature power of the annular zone at a point halfway across the width of the annular zone). The radial sagittal power of the annular zone will be more positive than the sagittal power of the central zone. The net radial-sagittal power of the annular zone will be the sum of the basic radial-sagittal power of the annular zone and the radial-sagittal add power. The value of Y may be between +0.5D and +10.0D. The value of Y may be +2.0D greater than the basic radial-sagittal power (i.e., the radial-sagittal add power at a point halfway across the width of the annular zone may be +2.0D). The value of Y may be +4.0D greater than the basic radial-sagittal power (i.e., the radial-sagittal add power at a point halfway across the width of the annular zone may be +4.0D). The value of Y may be +3.0D greater than the basic radial-sagittal power (i.e., the radial-sagittal add power at a point halfway across the width of the annular zone may be +3.0D).

[0080] Example combinations of values ​​for X and Y are described below. Those skilled in the art will immediately appreciate that many other combinations of values ​​for X and Y fall within the scope of the present disclosure.

[0081] The value of X may be +10.0D greater than the base radial curvature power (i.e., the radial curvature add power at a point halfway across the width of the annular zone may be +10.0D), and the value of Y may be +2.0D greater than the base radial sagittal power (i.e., the radial sagittal add power at a point halfway across the width of the annular zone may be +2.0D).

[0082] The value of X may be +12.0D greater than the base radial power (i.e., the radial power addition at a point halfway across the width of the annular zone may be +12.0D), and the value of Y may be +4.0D greater than the base radial power (i.e., the radial power addition at a point halfway across the width of the annular zone may be +4.0D).

[0083] The value of X may be +10.0D greater than the base radial curvature power (i.e., the radial curvature add power at a point halfway across the width of the annular zone may be +10.0D), and the value of Y may be +3.0D greater than the base radial sagittal power (i.e., the radial sagittal add power at a point halfway across the width of the annular zone may be +3.0D).

[0084] The value of X may be +11.0D greater than the base radial curvature power (i.e., the radial curvature add power at a point halfway across the width of the annular zone may be +11.0D), and the value of Y may be +3.0D greater than the base radial sagittal power (i.e., the radial sagittal add power at a point halfway across the width of the annular zone may be +3.0D).

[0085] The value of X may be +12.0D greater than the base radial curvature power (i.e., the radial curvature add power at a point halfway across the width of the annular zone may be +12.0D), and the value of Y may be +3.0D greater than the base radial sagittal power (i.e., the radial sagittal add power at a point halfway across the width of the annular zone may be +3.0D).

[0086] The radial curvature refractive power of the annular area may be greater than the circumferential curvature refractive power of the annular area. The circumferential curvature refractive power of the annular area may be the same as the basic circumferential curvature refractive power. The circumferential sagittal refractive power of the annular area may be the same as the circumferential basic sagittal refractive power.

[0087] The radial sagittal power of the annular zone may be greater than the radial sagittal power of the central zone over the width of the annular zone. In known center hyperopia lens designs with an annular zone providing additional power, where the center of curvature of the annular zone coincides with the optical axis of the central zone (this may be referred to as an on-axis annular zone), the radial sagittal power of the annular zone will be greater across the width of the annular zone than the radial sagittal power of the central zone. For known center hyperopia lens designs with annular zones providing additional power, where the center of curvature of the annular zone is displaced away from the optical axis of the central zone (this may be referred to as an off-axis annular zone), due to the inclination of the annular zone relative to the central zone, at the innermost edge of the annular zone, the radial sagittal power of the annular zone may be lower than the radial sagittal power of the central zone. The radial sagittal power may increase as the radial distance toward the outer edge of the annular zone increases. In these known designs, the annular zone may be radially inclined relative to the central zone so that the radial sagittal power at the midpoint across the width of the annular zone matches the radial sagittal power that the central zone would have if it were extended to the midpoint. The lens may have a radial sagittal power at the midpoint of the annular zone that matches the radial sagittal power the central zone would have if it were extended outward to the midpoint.

[0088] The combined effect of the annular zone being tilted relative to the central zone and the small radius of curvature of the annular zone means that the radial sagittal power of the annular zone may be greater than the radial sagittal power of the central zone across the entire width of the annular zone. Alternatively, there may be a drop in the sagittal power of the annular zone towards the boundary between the central zone and the annular zone.

[0089] The radial sagittal power may increase radially outward across the width of the annular region. The radial sagittal power may increase linearly from the innermost edge of the annular region radially outward.

[0090] The radial curvature power may be constant radially outward from the inner edge of the annular zone along a given meridian, or may increase radially outward from the inner edge of the annular zone along a given meridian.

[0091] The radial curvature power may vary along the meridian around the annular zone between a minimum value X1 and a maximum value X2, wherein both X1 and X2 are greater than the basic radial curvature power. Both X1 and X2 may be greater than the basic curvature power. The radial curvature power may vary periodically around the annular zone. The variation may be defined by a sine waveform, a triangular waveform, a square waveform, or a sawtooth waveform. The radial curvature power may vary continuously between X1 and X2. The position around the circumference of the annular zone is defined by an angle θ, wherein θ varies between 0° and 360°, and there may be maximum values ​​of the radial curvature power every 90°, every 45°, every 20°, or every 10°. X1 may be between +0.5D and +10.0D. X2 may be between +2.0D and +20.0D.

[0092] Alternatively and or additionally, the radial sagittal power of the annular zone may vary along the meridian around the annular zone between a maximum value Y1 and a minimum value Y2, wherein both Y1 and Y2 are greater than the basic radial sagittal power. Both Y1 and Y2 may be greater than the basic radial sagittal power. The radial sagittal power may vary periodically around the annular zone. The periodic variation of the radial sagittal power may vary around the entire annular zone or around a portion of the annular zone. The variation may be defined by a sine waveform, a triangular waveform, or a sawtooth waveform. The radial sagittal power may vary continuously between Y1 and Y2. The position around the circumference of the annular zone is defined by an angle θ, wherein θ varies between 0° and 360°, and there may be a maximum radial sagittal power every 90°, every 45°, every 20°, or every 10°. Y1 may be between +0.5 and +9.0D. Y2 may be between +2.0 and +19.0D.

[0093] In an embodiment of the present disclosure, wherein the radial curvature refractive power of the annular zone varies between a minimum value X1 and a maximum value X2, both X1 and X2 may be greater than Y. In an embodiment of the present disclosure, wherein the radial sagittal refractive power of the annular zone varies between a minimum value Y1 and a maximum value Y2, both Y1 and Y2 may be less than X. In an embodiment of the present disclosure, wherein the radial curvature refractive power of the annular zone varies between a minimum value X1 and a maximum value X2, and the radial sagittal refractive power of the annular zone varies between a minimum value Y1 and a maximum value Y2, the changes in the radial curvature refractive power and the radial sagittal refractive power may be in phase or out of phase. At any meridian around the annular zone, the radial curvature refractive power may be greater than the radial sagittal refractive power. Both the radial sagittal refractive power and the radius of curvature of the annular zone may vary with the meridians around the annular zone, so that the radial curvature refractive power of the lens remains constant, or is approximately constant when moving around the annular zone. For example, for a lens with a constant radial curvature power of +3.0D, the radial sagittal power may vary between +2.0D and +3.0D as the meridian moves around the annular zone. For a zone with a radial sagittal power of +3.0D, the radius of curvature of the annular zone will be centered on the first optical axis. For a zone with a radial sagittal power of +2.0D, the center of curvature of the annular zone will be shifted away from the first optical axis, and the radius of curvature of the annular zone may change.

[0094] The contact lens may include at least two concentric annular zones. For each of the at least two annular zones, at a point halfway across the width of the annular zone, the annular zone may have a radial curvature power of X, where X is greater than the base radial curvature power. Each of the at least two annular zones may have an off-axis center of curvature at a first distance from the optical axis, such that at a point halfway across its width, the annular zone has a radial sagittal power of Y, where Y is greater than the base radial sagittal power, and where Y is less than X. Each annular zone may include any of the features of the annular zones described above. For embodiments with at least two concentric annular zones, each annular zone may have the same radial curvature power distribution and the same radial sagittal power distribution, or each concentric annular zone may have a different radial curvature power distribution and / or radial sagittal power distribution. For embodiments with at least two concentric annular zones, the annular zones may be separated by a zone having a base power (i.e., the same power as the central zone).

[0095] The contact lens may include an elastomeric material, a silicone elastomeric material, a hydrogel material, or a silicone hydrogel material, or a combination thereof. As understood in the field of contact lenses, a hydrogel is a material that keeps water in equilibrium and is free of silicone-containing chemicals. A silicone hydrogel is a hydrogel containing silicone-containing chemicals. The hydrogel material and silicone hydrogel material as described in the context of the present disclosure 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 from about 30% to about 70% (wt / wt). In contrast, the silicone elastomeric material as described in the context of the present disclosure has a water content from about 0% to less than 10% (wt / wt). Typically, the silicone elastomeric material used with the present method or apparatus has a water content from 0.1% to 3% (wt / wt). Examples of suitable lens formulations include lens formulations with the following United States General Drug Names (USAN): methafilcon A, ocufilcon A, ocufilcon B, ocufilcon C, ocufilcon D, omafilcon A, omafilcon B, comfilcon A, enfilcon A, stenfilcon A, fanfilcon A, etafilcon A, 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.

[0096] Alternatively, the lens may comprise, consist essentially of, or consist of a silicone elastomeric material. For example, the lens may comprise, consist essentially of, or consist of a silicone elastomeric material having a Shore A hardness from 3 to 50. The Shore A hardness may be determined using conventional methods, as understood by one of ordinary skill in the art (for example, using method DIN 53505). For example, other silicone elastomeric materials may be obtained from NuSil Technology or Dow Chemical Company.

[0097] According to a second aspect, the present disclosure provides a method of manufacturing a lens. The method may include forming a contact lens, wherein the contact lens includes a central zone, the central zone having a first optical axis, a base curvature power, and a base sagittal power, and centered on a center of curvature on the first optical axis. The lens includes an annular zone. The annular zone has a radial curvature power of X. X is greater than the base radial curvature power. The annular zone has an off-axis center of curvature at a first distance from the optical axis, and such that at a point halfway across its width, the annular zone has a radial sagittal power of Y, wherein Y is greater than the base radial sagittal power, and wherein Y is less than X.

[0098] The lens may include any of the features set out above.

[0099] The manufacturing method may include forming a female mold part having a concave lens forming surface and a male mold part having a convex lens forming surface. The method may include filling a gap between the female and male mold parts with a bulk lens material. The method may further include curing the bulk lens material to form a lens.

[0100] The contact lens may be formed using a turning process. The lens may be formed by a molding process, a spin molding process, or a turning process, or a combination thereof. As understood by those skilled in the art, molding refers to modeling a lens by placing a lens forming material between a female mold part having a concave lens component forming surface and a male mold part having a convex lens component forming surface.

[0101] The method of manufacturing a lens may include designing a contact lens, wherein the designed lens is a lens according to an embodiment of the present disclosure and includes any of the features described above. The lens may be designed using modeling, which may be computer-implemented modeling.

[0102] The method may include modeling a first contact lens. The first contact lens may have a central zone, the central zone having a first optical axis. The central zone may have a base optical power and may be centered at a center of curvature on the first optical axis. The first contact lens may have an annular zone surrounding the central zone. The annular zone may have a radius of curvature centered at the first optical axis, wherein the curvature of the annular zone produces an additional optical power, wherein the net optical power of the annular zone is the sum of the base optical power and the additional optical power. The method may include modeling a second contact lens. The second contact lens may have the same central zone as the first contact lens. The central zone of the second lens may have the same base optical power as the first lens and may be centered at a center of curvature on the first optical axis. The second contact lens may have an annular zone surrounding the central zone. The annular zone of the second lens may have a radius of curvature centered at the first optical axis, and the curvature of the second annular zone of the second lens may produce an additional optical power greater than the additional optical power of the first contact lens. The net optical power of the second lens will be the sum of the base optical power and the additional optical power of the second lens. The net refractive power of the second lens may be greater than the net refractive power of the first lens. The method of designing a lens may include tilting an annular zone of the second lens within a model so that an outer circumference or outer edge of the annular zone matches an outer edge of an annular zone of the first lens while keeping an inner edge of the annular zone fixed. Tilting the annular zone of the second lens will move the center of curvature of the annular zone away from the first optical axis. Tilting the annular zone of the second lens will produce a third modeled lens, i.e., the tilted second lens. The third lens or the tilted second lens will have an annular zone that produces the same net refractive power as the untilted second contact lens, but with an off-axis center of curvature.

[0103] The method of manufacturing a lens may include manufacturing a lens based on a modeled third contact lens (i.e., tilting the second lens). Since a lens based on the third modeled lens will have a higher curvature than a lens based on the first modeled lens, such a lens may have a higher positive spherical aberration. A lens manufactured based on the third contact lens design may also have an extended depth of focus compared to a lens based on the first or second modeled lenses.

[0104] Figure 1A Schematic top view showing a contact lens 1 using a treatment zone providing a myopic defocused image to reduce the progression of myopia. Figure 1B exhibit Figure 1ASchematic side view of a lens 1 of FIG. 1 . The lens 1 includes 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 lens, thereby making the lens 1 easier to handle, providing ballast to prevent rotation of the lens 1, and providing a shaping zone that improves the comfort of the wearer of the lens 1. The optical zone 2 provides the optical functionality of the lens 1, and the optical zone includes an annular zone 3 and a central zone 5. The lens 1 has a basic radial curvature refractive power that is equal to the basic radial sagittal refractive power. The basic refractive power is generated by the radius of curvature of the surface of the lens 1. The center of curvature of the central zone 5 is located on the first optical axis 19 ( Figure 2A The annular zone 3 has a radial curvature refractive power greater than the basic radial curvature refractive power. The radial curvature refractive power of the annular zone 3 is provided by the curvature radius 6 of the annular zone 3, which is smaller than the curvature radius 7 of the central zone 5, as shown in FIG. Figure 3 The curvature center of the annular zone 3 is located on the first optical axis 19. The annular zone 3 has a greater refractive power than the central zone 5. Figure 2A As shown in FIG. 1 , the focus 11 of the annular zone 3 and the focus 15 of the central zone 5 share a common optical axis 19. The focus 11 of the annular zone 3 is located on the proximal focal plane 13, and the focus of the central zone 5 is located on the distal focal plane 17 further away from the back surface of the lens. Figure 2C , for a point source at infinity, the light focused by the central area 5 forms a focused image 23 at the far focal plane 17. The light focused by the central area 5 also produces an unfocused blurred light spot 27 at the near focal plane 13.

[0105] like Figure 2B , the light rays focused by the annular zone 3 form a focused image 21 at the proximal focal plane 13. The light rays focused by the annular zone 3 diverge after the proximal focal plane 13, and the divergent light rays produce an unfocused ring 25 at the distal focal plane 17. As discussed above, the unfocused ring image 25 can cause the wearer of the lens 1 to see a "halo" around the focused distance image.

[0106] Figure 4A It is a display Figure 1A and 1B A plot 31 showing the variation of the sagittal refractive power of the lens 1 shown in FIG. Figure 4B It is a display Figure 1A and 1B A plot 33 showing the variation in radial curvature refractive power of lens 1 is shown. Figure 4A and 4BThe variation in power along the radial diameter of lens 1 is shown. For this lens 1, because annular zone 3 has greater power than central zone 5, and because annular zone 3 has a coaxial center of curvature, the radial sagittal power across annular zone 3 (indicated by curve 35) is greater than across central zone 5. The radial curvature power across annular zone 3 (indicated by curve 37) is also greater than across central zone 5.

[0107] Figure 5A A schematic top view of another contact lens 101 with non-coaxial optics is shown. Figure 5B yes Figure 5A A schematic side view of a lens 101. Figure 1A The lens 101 includes 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 lens, thereby making the lens 101 easier to handle, providing ballast to prevent rotation of the lens 101, and providing a shaping zone that improves the comfort of the wearer of the lens 101. The optical zone 102 provides the optical functionality of the lens 101, and the optical zone includes an annular zone 103 and a central zone 105. The lens 101 has a basic radial curvature refractive power, which is equal to the basic radial sagittal refractive power. The basic refractive power is generated by the radius of curvature of the surface of the lens 101. The center of curvature of the central zone 105 is located at the first optical axis 119 ( Fig. 6A The annular zone 103 has a radial curvature refractive power greater than the basic radial curvature refractive power. The radial curvature refractive power of the annular zone 103 is provided by the curvature radius of the annular zone 103, which is smaller than the curvature radius of the central zone 105. However, Figure 1A and 1B Compared with lens 1, Figure 5A and 5B In the lens 101 shown in FIG. 1 , the curvature of the annular region 103 cannot be defined by a single sphere, and the center of curvature of the annular region 103 is not located on the first optical axis 119. Fig.6D The annular region 103 is tilted relative to the central region 105 so that Figure 1A and 1B In the case of the lens 1, the outer edge of the annular zone 103 is higher than its inner edge (at Figure 5B ), which changes the radial sagittal power of the annular zone 103, but does not change the radial curvature power of the annular zone 103. Fig.6D , the front surface of the central region 105 defines a portion of the surface of a sphere of larger radius 107. The front surface of the annular region 103 defines a curved annular surface with smaller radius 106.

[0108] At the distal focal plane 117, light rays traveling through the central region 105 are focused. The annular region 103 acts as a beam stop, which results in a small spot size 133 of the light 124 at the distal focal plane 117, as shown in FIG. Figure 6C Displayed in.

[0109] No single image is formed at the near-end focal plane 113. Figure 6B As shown in FIG. 1 , at the near focal plane 113 , for a point source at infinity, light rays traveling through the central region 105 produce a blur circle 128 , Figure 1A , 1B However, light from a distant point source traveling through the annular region 103 produces a focusing ring 122, such as Figure 6B , which surrounds the blur circle 128. Figure 6B Shows the light pattern produced for a distant point source. Figure 1A and 1B Compared with the lens 1, Figure 5A and 5B The lens 101 does not produce a single image or coaxial image at the near focal plane 113, which can be used to avoid the need for the eye to adapt to near objects. For distant elongated objects, the focused image formed at the near focal plane 113 is the convolution of (i) a focused image of the elongated object that would be obtained using a conventional lens having the optical power of the annular zone 103 and (ii) an optical transfer function representing the optical effect of the annular zone 103.

[0110] and Figure 1A and 1B Compared with lens 1, no ring or "halo" effect appears at the distal focal plane 117.

[0111] Fig. 7A It is a display Figure 5A and 5B A plot 131 of the variation of the sagittal power of the lens 101 shown in FIG. 1 , and Figure 7B It is a display Figure 5A and 5B A plot 133 of the variation in refractive power of a lens based on radial curvature is shown. Fig. 7A and 7B1 shows the variation in power along the radial diameter of the lens 101. For this lens 101, since the annular zone 103 has greater power than the central zone 105, and this means that the radial curvature power (indicated by curve 137) across the annular zone 103 is greater than across the central zone 105. However, the annular zone 103 is tilted relative to the central zone 105, so that the annular zone 103 has an off-axis center of curvature. The tilt of the annular zone 103 relative to the central zone 105 means that the radial sagittal power is more negative at the boundary between the central zone 105 and the annular zone 103 than the radial sagittal power of the central zone, as shown by curve 135. The radial sagittal power may increase with increasing radial distance towards the outer edge of the annular zone 103.

[0112] Fig. 8A A schematic top view of a contact lens 201 according to an embodiment of the present disclosure is shown. Figure 1A and 1B Lenses 1 and Figure 5A and 5B The lens 101 includes 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, thereby making the lens 201 easier to handle, providing ballast to prevent rotation of the lens 201, and providing a shaping zone that improves the comfort of the wearer of the lens 201. The optical zone 202 provides the optical functionality of the lens 201, and the optical zone includes an annular zone 203 and a central zone 205. The central zone 205 of the lens 201 has a basic radial curvature refractive power that is equal to the basic radial sagittal refractive power. In this example embodiment of the present disclosure, the basic radial curvature refractive power of the central zone is 0.0D, which is equal to the basic radial sagittal refractive power of the central zone 205. This basic refractive power is generated by the radius of curvature of the surface of the lens 201. The center of curvature 244 of the central zone 205 is located at the first optical axis 219 ( Fig. 9 The annular zone 203 has a radial curvature refractive power greater than the basic radial curvature refractive power. The radial curvature refractive power of the annular zone 203 is provided by the curvature radius of the annular zone 203, which is smaller than the curvature radius of the central zone 205.

[0113] At point A halfway across the width of the annular zone (at Fig. 8A and 8B The radial curvature power of the annular zone has a value of about +3.5D. Fig. 8A and 8B For the example lens 201 shown in FIG. 2 , for a given radial position, the radial curvature power is constant at all meridians around the annular zone 203. This means that the radial curvature power will be constant along the Fig. 8A and 8BThe dashed curve 241 shown in FIG. 1 has the same value, which is a curve extending around the annular region 203 at a point halfway across the width of the annular region 203. In this example embodiment of the present disclosure, X is approximately +3.5D. Similar to Figure 5A and 5B In the lens shown in FIG. 2 , the annular zone 203 of the lens 201 has been tilted relative to the central zone 205 so that the center of curvature 243 of the annular zone 203 deviates from the first optical axis 219. Fig. 9 . Tilting the annular zone 203 relative to the central zone 205 reduces the radial sagittal power at the boundary between the central zone 205 and the annular zone 203. At point A, halfway across the width of the annular zone 203, the radial sagittal power has a value Y, which is greater than the base radial sagittal power, but less than X. For this example embodiment, for a given radial position, Y is about +2.25D, and the radial sagittal power is constant at all meridians around the annular zone 203. This means that the radial sagittal power will be along Fig. 8A and 8B The dashed curve 241 shown in , which has the same value, is a curve extending around the annular region 203 .

[0114] At the distal focal plane 217, light rays traveling through the central zone 205 are focused. Light rays traveling through the annular zone 203 are directed toward the sagittal additional focal plane 218.

[0115] Fig. 10A It is a display across Fig. 8A and 8B 231 shows the variation of the curvature power of the radial diameter of the lens 201 shown in FIG. This plot 231 shows the average values ​​of the radial and circumferential curvature powers. Across the central zone 205, the curvature power of the lens 201 is constant and approximately zero. At the boundary between the central zone 205 and the annular zone 203, the curvature power shows a sharp increase, as indicated by curve 235. This is due to the increase in the radial curvature power. The circumferential curvature power will not change significantly at the boundary between the central zone 205 and the annular zone 203, but the radial curvature power will increase, and therefore the average curvature power (indicated by curve 235) will increase to the average value of the circumferential curvature power and the radial curvature power at the boundary between the central zone 205 and the annular zone 203.

[0116] Fig. 10B It is a display across Fig. 8A and 8B233 shows the variation of the sagittal power of the lens 201 as a function of the radial diameter shown in FIG. This plot 233 shows the average values ​​of the radial and circumferential sagittal power. Across the central zone 205 of the lens 201, the sagittal power is constant and has a value of 0.0D. At the boundary between the central zone 205 and the annular zone 203, the sagittal power of the annular zone 203 increases sharply due to the increase in the radial sagittal power, as indicated by curve 237. The radial sagittal power increases in an approximately linear manner extending radially outward across the width of the annular zone 203. Fig. 7A Compared to the sagittal power curve shown for a lens with an off-axis add power annular zone 203 in FIG. 1 , there is no drop in sagittal power at the boundary between the central zone 205 and the annular zone 203. This is because the annular zone 203 has been tilted relative to the central zone in a manner that increases the radial sagittal power at the boundary between the central zone 205 and the annular zone 203. The increase in sagittal power at the boundary between the central zone 205 and the annular zone 203 will not be as great as for a lens with an on-axis add power annular zone (e.g., as in FIG. 1 ). Figure 1A and 1B as big as shown in Figure 1.

[0117] like Fig.11A In the display, for Fig. 8A and 8B In the lens 201 shown in FIG. 1 , at the distal focal plane 217, light traveling through the central region 205 will form a focused image 223, as shown in FIG. Fig. 11B . Light traveling through the annular region 203 will produce an unfocused ring 225 at the distal focal plane 217. At the first proximal focal plane 218, for a point source at infinity, light traveling through the central region 205 will produce a first blur circle 227 and light traveling through the annular region 203 will produce a second blur circle 229, as shown in FIG. Fig. 11C At the second proximal focal plane 220, light traveling through the central region 205 will generate a third blur circle 231 and light traveling through the annular region 203 will generate a focus ring 233 located within the third blur circle 231, as shown in FIG. Fig.11D Displayed in. Fig. 12A A schematic top view of a contact lens 301 according to an embodiment of the present disclosure is shown. Fig. 8A and 8BThe lens 201 of the present invention includes an optical zone 302 that generally covers the pupil, and a peripheral zone 304 located above the iris. The peripheral zone 304 provides mechanical functions, including increasing the size of the lens, thereby making the lens 301 easier to handle, providing ballast to prevent rotation of the lens 301, and providing a shaping zone that improves the comfort of the wearer of the lens 301. The optical zone 302 provides the optical functionality of the lens 301, and the optical zone 302 includes an annular zone 303 and a central zone 305. The lens 301 has a basic radial curvature refractive power that is equal to the basic radial sagittal refractive power. In this example embodiment of the present disclosure, the basic radial curvature refractive power of the central zone is -2.0D, and the basic radial sagittal refractive power of the central zone is -2.0D. The basic refractive power is generated by the radius of curvature of the surface of the lens 301. The center of curvature of the central zone 305 is located on the first optical axis. The annular zone 303 has a radial curvature refractive power greater than the basic radial curvature refractive power. The radial curvature power of the annular zone 303 varies with the meridian around the annular zone 303. In this example embodiment, the radial curvature power is approximately constant as it extends radially outward along any meridian. Fig. 12A and 12B The radial curvature power varies between a minimum value X1 and a maximum value X2, as indicated by the dashed line 341 in FIG. 3 . Both X1 and X2 are greater than the base curvature power of the central zone 305. X1 is +2.0D and X2 is +10.0D. The radial curvature power varies sinusoidally around the annular zone, with Fig.14 Using an angle θ to define positions around the circumference of the annular zone 303, where θ varies between 0° and 360°, for this example embodiment, the radial curvature power has a maximum value of X2 at a point halfway across the width of the annular zone 303 every 180°, such that the radial curvature at points A and C is X2. The radial curvature power has a minimum value of X1 at a point halfway across the width of the annular zone 303 every 180°, such that the radial curvature at points B and D is X1.

[0118] The radial curvature power of the annular zone 303 is produced by the curvature of the surface of the annular zone 303. At all points around the annular zone 303, the radius of curvature of the annular zone 303 is less than the radius of curvature 307 of the central zone 305. At all points around the annular zone 303, the annular zone 303 has an off-axis center of curvature. In this example embodiment, the radius of curvature of the annular zone 303 varies with the meridian, and this produces a varying radial curvature power. Fig.13A As shown in FIG. 1 , the radial diameter along which the radial curvature has a maximum value ( Fig. 12A The radius of curvature 306e of the annular region 303 will be the smallest ( Fig.13A ).like Fig. 13BAs shown in FIG. 1 , the radial diameter along which the radial curvature has a minimum value ( Fig. 12A As shown in FIG. 5 , the radius of curvature 306f of the annular region 303 will be the largest.

[0119] For this lens 301, the sagittal power has a constant value Y at a point halfway across the width of the annular zone 303, and a constant value around the annular zone 305. Y is less than X, but Y is greater than the base power of the central zone 305 of the lens 301, as shown in FIG. Fig.14 Schematically shown in .

[0120] In other embodiments of the present disclosure (not shown), the lens is similar to Figures 8A to 11D The lens shown and described in FIG. 1, but at point A halfway across the width of the annular zone (eg Fig. 8A and 8B ), the radial curvature refractive power of the annular zone is approximately +10.0D greater than the basic radial curvature refractive power of the central zone (i.e., the radial curvature additional refractive power is approximately +10.0D), and the radial sagittal refractive power of the annular zone is approximately +2.0D greater than the basic radial sagittal refractive power of the central zone (i.e., the radial sagittal additional refractive power is approximately +2.0D).

[0121] In other embodiments of the present disclosure (not shown), the lens is similar to Figures 8A to 11D , but at point A halfway across the width of the annular zone, the radial curvature power of the annular zone is approximately +12.0D greater than the base radial curvature power of the central zone (i.e., the radial curvature add power is approximately +12.0D), and the radial sagittal power of the annular zone is approximately +4.0D greater than the base radial sagittal power of the central zone (i.e., the radial sagittal add power is approximately +4.0D). Advantageously, this lens will exhibit a sharp increase in radial sagittal power at the boundary between the central zone and the annular zone. The increase in radial sagittal power may exceed +2.0D. For lens wearers with relatively small pupil diameters (for example, younger lens wearers), this sharp increase in radial sagittal power at the boundary between the central zone and the annular zone may improve the therapeutic effect of the annular zone.

[0122] In other embodiments of the present disclosure (not shown), the lens is similar to Figures 8A to 11D The lens shown and described in FIG. 1, but at point A halfway across the width of the annular zone (eg Fig. 8A and 8B ), the radial curvature refractive power of the annular zone is approximately +11.0D higher than the basic radial curvature refractive power of the central zone (i.e., the radial curvature additional refractive power is approximately +11.0D), and the radial sagittal refractive power of the annular zone is approximately +3.0D higher than the basic radial sagittal refractive power of the central zone (i.e., the radial sagittal additional refractive power of the annular zone is approximately +3.0D).

[0123] In other embodiments of the present disclosure (not shown), the lens is similar to Figures 8A to 11D The lens shown and described in FIG. 1, but at point A halfway across the width of the annular zone (eg Fig. 8A and 8B ), the radial curvature refractive power of the annular zone is approximately +12.0D higher than the basic radial curvature refractive power of the central zone (i.e., the radial curvature additional refractive power is approximately +12.0D), and the radial sagittal refractive power of the annular zone is approximately +3.0D higher than the basic radial sagittal refractive power of the central zone (i.e., the radial sagittal additional refractive power of the annular zone is approximately +3.0D).

[0124] In other embodiments of the present disclosure (not shown), the lens is similar to Figures 8A to 11D The lens shown and described in FIG. 1, but at point A halfway across the width of the annular zone (eg Fig. 8A and 8B ), the radial curvature power of the annular zone is approximately +10.0D greater than the basic radial curvature power of the central zone (i.e., the radial curvature add power is approximately +10.0D), and the radial sagittal power of the annular zone is approximately +3.0D greater than the basic radial sagittal power of the central zone (i.e., the radial sagittal add power is approximately +3.0D). In other embodiments of the present disclosure, the lens may have an annular zone with a radial curvature power that varies with the meridian in a stepped manner or in a sawtooth manner. The variation may be periodic or non-periodic. There may be peaks in the radial curvature power every 180°, every 90°, every 20°, every 10°, or every 5°. By way of example, in Fig.15A C shows the periodic variation of the radial refractive power, which can be the variation of the radial sagittal or curvature refractive power.

[0125] In other embodiments of the present disclosure, both the radial curvature power and the radial sagittal power may vary with the meridian around the annular zone. The variation of the radial sagittal power may be in phase or out of phase with the variation of the radial curvature power. At all points around the circumference of the annular zone, the radial sagittal power may be less than the radial curvature power, but greater than the base power of the central zone.

[0126] In other embodiments of the present disclosure, the lens may include two or more concentric annular zones. For each of the annular zones, at a point halfway across the width of the annular zone, the annular zone has a radial curvature power of X, where X is greater than the base radial curvature power. Each of the at least two annular zones may have an off-axis center of curvature at a first distance from the optical axis, such that at a point halfway across its width, the annular zone has a radial sagittal power of Y, where Y is greater than the base radial sagittal power, and where Y is less than X. Each concentric annular zone may be separated by a zone having a base power (i.e., the same power as the central zone).

[0127] In other embodiments of the present disclosure, the lens may include two or more concentric annular zones. At least one of the annular zones is Figure 5A and 6A , and for at least one of the other annular zones, at a point halfway across the width of the annular zone, the annular zone has a radial curvature power of X, where X is greater than the base radial curvature power. Each of the at least two annular zones may have an off-axis center of curvature at a first distance from the optical axis, such that at a point halfway across its width, the annular zone has a radial sagittal power of Y, where Y is greater than the base radial sagittal power, and where Y is less than X.

[0128] Fig.16 A method 501 for designing a contact lens is shown, wherein the lens is a lens according to an embodiment of the present disclosure. In a first step 503, the method involves modeling a first contact lens. The first contact lens has a central zone having a first optical axis. The central zone has a basic refractive power and is centered on a center of curvature on the first optical axis. In this example, the central zone of the first contact lens has a basic refractive power of -3.0D. The first contact lens has an annular zone surrounding the central zone. The annular zone has a radius of curvature centered on the first optical axis. The curvature of the annular zone produces an additional refractive power. In this example, the annular zone has a curvature that produces an additional refractive power of +2.0D. The net refractive power of the annular zone is the sum of the basic refractive power and the additional refractive power, and thus in this example, the net refractive power of the annular zone is -1.0D. In a second step 505, the method involves modeling a second contact lens. The second contact lens has the same central zone as the first contact lens, and thus, in this example, the second contact lens has a basic refractive power of -3.0D. The second contact lens is also centered on the center of curvature on the first optical axis. The second contact lens has an annular zone surrounding the central zone. The annular zone of the second lens has a radius of curvature also centered on the first optical axis, but the curvature of the annular zone produces an additional refractive power greater than the additional refractive power of the first lens. In this example, the curvature of the second annular zone produces an additional refractive power of +4.0D. The net refractive power of the second lens is the sum of the basic refractive power and the additional refractive power, and therefore in this example, the net refractive power of the second lens is +1.0D. In a third step 507, the method includes tilting the annular zone of the second lens within the mold so that the outer edge of the second annular zone matches the outer edge of the annular zone of the first lens while keeping the inner edge of the second annular zone fixed. This produces a third lens (corresponding to the tilted second lens) having an annular zone with the same net refractive power as the untilted second lens. In this example, the third lens or the tilted second lens has an annular zone with a net refractive power of +1.0D, but with a center of curvature that is not on the first optical axis.

[0129] Fig.17601, 603, 605 are schematic diagrams of three modeled lenses 601, 603, 605 modeled as part of the method of designing lenses described above. The three lenses share a common central zone 607 having a curvature centered on the first optical axis that provides a base power of -3.0D. The first lens 601 has an annular zone 601a having a curvature that produces an additional power of +2.0D, such that the net power of the annular zone is -1.0D. The center of curvature of the annular zone 601a of the first lens 601 is centered on the first optical axis. The second lens 603 has an annular zone 603a having a curvature that produces an additional power of +4.0D, such that the net power of the annular zone is +1.0D. The center of curvature of the annular zone 603a of the second lens 603 is also centered on the first optical axis. The inner edge of the annular zone 601a of the first lens 601 and the inner edge of the annular zone 603a of the second lens 603 coincide at point 607. The third lens 605 is a tilted version of the second lens 603. The annular zone 605a of the third lens 605 has a curvature that produces an additional refractive power of +4.0D, has the same additional refractive power and the same net refractive power as the second lens 603. The inner edge of the annular zone 605a of the third lens coincides with the same point 607 as the first lens 601 and the second lens 603, but the outer edge of the annular zone 605a of the third lens 605 has been tilted to coincide with the outer edge of the annular zone 601a of the first lens 601 at point 611. The annular zone 605a of the third lens 605 has a net refractive power of +1.0D, but has a center of curvature that is not on the first optical axis.

[0130] Those of ordinary skill in the art will appreciate that the features of these example embodiments may be combined in other embodiments falling within the scope of the present disclosure.

[0131] Although in the foregoing description, reference is made to wholes or elements with known obvious or foreseeable equivalents, such equivalents are incorporated herein as if individually set forth. Reference should be made to the claims for determining the true scope of the present disclosure, which should be interpreted as covering any such equivalents. The reader will also understand that wholes or features of the present disclosure described as advantageous, convenient, or the like are optional and do not limit the scope of the independent claims. In addition, it should be understood that such selected wholes or features, while having possible benefits in some embodiments of the present disclosure, may not be desired and therefore may not exist in other embodiments.

Claims

1. A contact lens, the lens comprising an optical zone, comprising: a central area, the central area having a first optical axis, a basic refractive power, a center of curvature on the first optical axis, and a first radius of curvature; and an annular zone, wherein the annular zone is inclined relative to the central zone and has an additional refractive power of radial curvature greater than the basic refractive power, wherein Light rays traveling through the central region form a focused image at a distal focal plane, and light rays traveling through the annular region do not form a light spot at the distal focal plane; and The radial sagittal refractive power increases at the boundary between the central zone and the annular zone, and the radial sagittal refractive power increases with increasing radial distance toward the outer edge of the annular zone.

2. A contact lens according to claim 1, wherein the increase in sagittal-sagittal power at the boundary between the central zone and the annular zone is greater than +2.0D.

3. A contact lens according to claim 1 or claim 2, wherein the basic refractive power of the central zone is generated by the curvature of the front surface and / or the back surface of the lens.

4. A contact lens according to any preceding claim, wherein the radial curvature power of the annular zone is produced by the curvature of the front and / or back surface of the lens.

5. A contact lens according to any preceding claim, wherein at a point halfway across the radial width of the annular zone, the annular zone has a radial curvature power that is +10.0D greater than the base power.

6. A contact lens according to claim 1 or any one of claims 3 to 5, wherein at a point halfway across the radial width of the annular zone, the annular zone has a radial sagittal power that is +2.0D greater than the base power.

7. A contact lens according to any one of claims 1 to 4, wherein at a point halfway across the radial width of the annular zone, the annular zone has a radial sagittal refractive power that is +4.0D greater than the basic refractive power, and a radial curvature refractive power that is +12.0D greater than the basic refractive power.

8. A contact lens according to any preceding claim, wherein the base refractive power of the lens is between 0.5D and -15.0D.

9. A contact lens according to any preceding claim, wherein the lens comprises an elastomeric material, a silicone elastomeric material, a hydrogel material or a silicone hydrogel material or a mixture thereof.

10. A contact lens according to any preceding claim, wherein the lens is formed using a turning process or a moulding process.

11. A method for manufacturing a contact lens, the method comprising: A contact lens according to any preceding claim is formed using a turning process or a moulding process.

12. The method of claim 11, comprising the step of designing the contact lens, wherein designing the contact lens comprises: (a) Modeling a first contact lens, the first contact lens having: a central region, wherein the central region has a base refractive power and a center of curvature on a first optical axis; and an annular zone surrounding the central zone, the annular zone having a radius of curvature centered on the first optical axis, wherein the curvature of the annular zone produces a first additional refractive power greater than the basic refractive power; (b) modeling a second contact lens, wherein the second contact lens has a central zone that is the same as the first contact lens, and an annular zone surrounding the central zone, wherein the annular zone has a radius of curvature centered on the optical axis, and the annular zone produces a second add power that is greater than the first add power of the first contact lens; (c) within the mold, tilting the annular zone of the second contact lens so that an outer edge of the annular zone matches an outer edge of the annular zone of the first lens, thereby producing a third contact lens, wherein the annular zone of the third lens has the second add refractive power of the annular zone of the second contact lens, but the center of curvature is the first distance from the first optical axis.

13. The method of claim 12, comprising manufacturing a lens based on the modeled third contact lens.

Images