Myopia Control Lenses and Related Methods

Abstract

Improved ophthalmic lenses for myopia control, methods for making the ophthalmic lenses, and methods for inhibiting the progression of myopia in an individual are provided. The present invention provides an ophthalmic lens for myopia control. A first surface of the lens varies across the lens to form a first surface power map. A second surface of the lens varies across the lens to form a second surface power map. The first and second surface power maps each comprise a spiral. The spirals formed by the first and second surface power maps twist in opposite directions. Related methods are also described.

Description

[Technical field]

[0001] The present invention relates to ophthalmic lenses and methods for reducing the progression of myopia (i.e., myopia control). More specifically, but not by way of limitation, the present invention relates to ophthalmic lenses for myopia control having a first surface and a second surface, the first and second surfaces providing respective first and second surface power maps, the first and second surface power maps comprising counter-rotating spirals. The present invention also relates to methods of making and using such lenses. [Background technology]

[0002] Myopia control lenses are ophthalmic lenses that attempt to control the progression of myopia in the wearer. This control is typically achieved by subdividing the ophthalmic lens into a plurality of regions. A first subset of the regions is provided with a first lens power corresponding to a first focusing distance (e.g., for correcting distance vision for an unaccommodated eye). A second subset of the regions has a second lens power selected to provide myopic defocus.

[0003] In the case of contact lenses for myopia control, these multiple regions are generally formed as concentric circles centered on the optical axis of the contact lens, which alternate between a first lens power providing corrective vision and a second lens power providing myopic defocus. Thus, the power map of the myopia control contact lens comprises two alternating concentric circles of first and second lens powers. However, under low light conditions, the pupil of the wearer's eye expands to provide a larger opening for the incoming light, increasing the amount of light admitted into the eye, thereby providing improved low light vision. When conditions become brighter, the pupil contracts to provide a smaller opening, thereby limiting the amount of light admitted into the eye. As the wearer's pupil expands and contracts, the number of concentric rings on the contact lens positioned across the wearer's entrance pupil will also change. As the pupil expands, a greater number of concentric rings will be positioned across the wearer's entrance pupil. Similarly, as the pupil contracts, a smaller number of concentric rings will be positioned across the wearer's entrance pupil. These concentric rings alternate between the first and second lens powers, so that as the wearer's pupil constricts and dilates, the amount of the second lens power providing myopic defocus positioned across the wearer's entrance pupil changes. In some cases, the pupil may even constrict to the point where none of the second lens power providing myopic defocus is positioned across the wearer's entrance pupil, resulting in the lens failing to provide effective control of myopia progression.

[0004] In addition to changing pupil size, lens decentration and, in the case of spectacle lenses, movement of the wearer's eye behind the lens can also impede the ability of the lens to provide effective myopia control. Each of the above factors can cause variations in the ratio of the first lens power to the second lens power.

[0005] Several lens designs have been described to attenuate the progression of myopia. MISIGHT (CooperVision) was the first such contact lens to receive regulatory approval in the United States. The MISIGHT contact lens is a bifocal contact lens that provides myopic defocus images at both near and distance viewing distances. The bifocal design comprises a central distance correction section surrounded by a peripheral zone by alternating rings of different optical powers. Another concentric ring lens design, called the Defocus Integrated Soft Contact (DISC) lens, has been developed by Hong Kong Polytechnic University (HKPU) and marketed by Vision Science and Technology Co. Ltd. HKPU and Hoya Vision Care have developed a myopia control spectacle lens called the Defocus Integrated Multiple Segment (DIMS) eyeglasses under the name MyoSmart (Hoya). Additionally, another spectacle lens for myopia control is being developed by Sightglass Vision. Examples of myopia suppressing ophthalmic lenses are described in patent documents including US7766478, US7832859, US8240847, USRE47006, US8950860, US9594259, US9829722, US10061143, US10416476, US10268050, US10429670, US20190212580, US20180275427, US20160377884, and US20170115509.

[0006] It is important to ensure that myopia control lenses reduce the formation of additional undesired images. If the parts of the lens that provide myopic defocus also form additional images, the lens wearer may simply "tune in" to the additional images rather than engaging the accommodation function of his or her eye. This is undesirable. It will be appreciated that if a lens design includes separate areas, only some of which are dedicated to myopia control, the above limitations to prevent unintended image formation apply to the areas dedicated to myopia control and not to the entire lens. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US7766478 [Patent Document 2] US7832859 [Patent Document 3] US8240847 [Patent Document 4] USRE47006 [Patent Document 5] US8950860 [Patent Document 6] US9594259 [Patent Document 7] US9829722 [Patent Document 8] US10061143 [Patent Document 9] US10416476 [Patent Document 10] US10268050 [Patent Document 11] US10429670 [Patent Document 12] US20190212580 [Patent Document 13] US20180275427 [Patent Document 14] US20160377884 [Patent Document 15] US20170115509 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention seeks to alleviate the above-mentioned problems. Alternatively or additionally, the present invention seeks to provide an improved ophthalmic lens for myopia control. [Means for solving the problem]

[0009] According to a first aspect, the present invention provides an ophthalmic lens for inhibiting myopia progression. A first surface of the ophthalmic lens is molded to form a first surface power map. A second surface of the ophthalmic lens is molded to form a second surface power map. The first surface power map comprises a spiral. The second surface power map also comprises a spiral. The spiral formed by the first surface power map and the spiral formed by the second surface power map twist in opposite directions.

[0010] The total power map of the contact lens is determined by the superposition of the first and second surface power maps. The spiral provided by the first surface power map and the spiral provided by the second surface power map twist in opposite directions. The first and second surface power maps can therefore be said to comprise counter-rotating spirals. The superposition of the two counter-rotating spirals formed by the first and second surface power maps results in a lens power map that approximates a pseudo-dartboard pattern of alternating annular rings or multiple defocus segments. The total lens power map varies between a first lens power that provides distance vision and a second lens power that provides near-vision defocus. Since this ophthalmic lens is designed as a myopia suppression lens, the wearer of this ophthalmic lens will generally be between about 5 years old and 18 years old, and therefore the wearer's eye is very likely to be able to accommodate. Thus, although a first lens power is selected for distance vision, it will be appreciated that the wearer, due to his or her ability to accommodate, is able to see for near distances through the portion of the lens that provides the first lens power.

[0011] Contact lenses having a power map that approximates a pseudo-dartboard pattern can be effective in providing myopia control. Such lens power maps also provide a more stable ratio of lens powers (i.e., the ratio of lens powers that provide distance vision accommodation to lens powers that provide near vision defocus) in the presence of variations in the wearer's pupil size. As light conditions change, the wearer's pupils will dilate and constrict to adjust the amount of light admitted into the eye. When conditions become brighter, the pupils constrict to reduce the amount of light allowed into the eye. When conditions become darker, the pupils dilate to allow more light into the eye. Some prior art myopia control contact lenses use alternating concentric rings of a first lens power that provides distance vision accommodation and a second lens power that provides near vision defocus, e.g., a central circle of the first lens power surrounded by a peripheral circle of the second lens power. These contact lenses are subject to variations in the ratio of lens power across the wearer's entrance pupil (i.e., the ratio of lens power providing distance vision accommodation to lens power providing near defocus) as the wearer's pupil dilates and constricts. These variations can impair the ability of the lenses to provide effective myopia control. That is, contact lenses according to the present invention are capable of providing effective myopia control in the presence of varying pupil dilation.

[0012] The spiral power map disclosed herein can provide a constant ratio of lens power providing near defocus to lens power providing distance accommodation over the entire diameter range including the spiral. Thus, a contact lens with a spiral power map can maintain either a substantially constant ratio of accommodation to near defocus (if the spiral covers the entire lens) or a monotonically changing ratio (if the spiral covers only a radial sub-portion of the lens) when the pupil contracts or expands. The pseudo-dartboard pattern provided by the superposition of two counter-rotating spirals also provides this same advantage. Thus, a contact lens with a pseudo-dartboard power map reduces the variation in the ratio of near defocus to distance accommodation in the presence of variable lighting conditions.

[0013] It will be appreciated by those skilled in the art that if the power map varies smoothly (e.g., sinusoidally), the power map will comprise lens powers other than simply a first lens power associated with distance vision accommodation and a second lens power associated with near vision defocus. In such a case, the power map will further comprise areas having lens powers between the first and second powers. It will be appreciated that this does not affect or reduce the above-mentioned advantage of providing a consistent and stable variation of the ratio of accommodation and near vision defocus positioned across the wearer's entrance pupil. It will be appreciated by those skilled in the art that this advantage comes from the fact that for spiral and pseudo-dartboard power maps, the configuration of lens power at a particular radius does not vary with radial distance from the optical axis of the lens.

[0014] According to a second aspect of the present invention, there is also provided a method of manufacturing an ophthalmic lens for myopia control. The method comprises operating a lathe to shape first and second surfaces of at least one of a lens, a mold for a lens, or an insert for manufacturing a mold for a lens. The first surface is shaped to form a first surface power map. The second surface is shaped to form a second surface power map. The first surface power map and the second surface power map each comprise a spiral. The spiral formed by the first surface power map and the spiral formed by the second surface power map twist in opposite directions.

[0015] According to a third aspect of the present invention, there is also provided a method of using an ophthalmic lens as described herein. The method may be effective in attenuating the progression of refractive errors, such as attenuating the progression of myopia or hyperopia. The method includes providing the ophthalmic lens to an individual having an eye capable of accommodation. The method may include providing the ophthalmic lens to an individual between about 5 and about 18 years of age. The providing step may be performed by an ophthalmic practitioner, such as an optometrist or an optometrist. Alternatively, the providing step may be performed by a lens distributor who arranges for delivery of the ophthalmic lens to the lens wearer.

[0016] It will of course be appreciated that features described in relation to one aspect of the invention may be incorporated in other aspects of the invention, for example a method of the invention may incorporate any of the features described in relation to an apparatus of the invention, and vice versa.

[0017] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which: [Brief description of the drawings]

[0018] [Figure 1] 1 illustrates a contact lens according to an exemplary embodiment of the present invention. [Diagram 2] FIG. 2 shows a first surface power map of the optical zone of a contact lens according to a first embodiment of the present invention. [Diagram 3] FIG. 2 shows a second surface power map of the optical zone of the contact lens of the first embodiment. [Figure 4] FIG. 2 shows a lens power map of the optical zone of a first embodiment of a contact lens. [Diagram 5] FIG. 2 shows a power map of the optical zone of a contact lens according to a second embodiment. [Figure 6] 10 is a flow diagram illustrating steps of a method according to a fifth embodiment of the present invention. [Figure 7] FIG. 13 shows a spectacle lens according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] According to a first aspect, the present invention provides an ophthalmic lens for myopia control. A first surface of the ophthalmic lens is varied to form a first surface power map. A second surface of the ophthalmic lens is varied to form a second surface power map. It will be appreciated by those skilled in the art that the variation of the surface comprises a variation of the curvature of the surface. The first surface power map and the second surface power map each comprise a spiral. The spiral provided by the first surface power map and the spiral provided by the second surface power map twist in opposite directions.

[0020] The helix formed on each of the first and second surfaces may be formed by substantially periodically varying the power of the respective surface both radially outward from the optical axis of the lens and angularly about the optical axis.

[0021] It will be appreciated by those skilled in the art that the first surface power map does not necessarily have to be formed on the entire first surface. In fact, the first surface power map can be formed on a portion of the first surface. In such a case, the variations of the first surface outside this portion are not relevant to the first surface power map. The same applies to the second surface and the second surface power map. For example, in the case of a contact lens, the surface power map can be formed only by the optical zone of the contact lens, not by the surrounding peripheral zone. Thus, in this case, the above-mentioned portion of the surface corresponds to the optical zone of the contact lens.

[0022] Ophthalmic lenses that provide first and second surfaces with counter-rotating helices can provide lens power profiles that are effective in myopia control. It is believed that myopic defocus may affect eye growth. However, although it has been demonstrated that myopia control lenses are effective in inhibiting myopia progression, the mechanism by which this effect is achieved has not yet been fully grasped or understood. The effectiveness of the disclosed structures and lens designs for use in myopia control does not depend on the correctness of the above-mentioned theories regarding the exact mechanism by which myopia control lenses function.

[0023] The ophthalmic lens may be a contact lens. Alternatively, the ophthalmic lens may be an intraocular lens or a spectacle lens.

[0024] It will be appreciated that a variation in the first surface power map does not necessarily require a variation in the second surface power map. In fact, the first surface power map may vary independently of the second surface power map, and vice versa. Thus, each of the optional features described subsequently for the radial and angular variation characteristics may be applied to the first and second surface power maps together or separately.

[0025] The spiral may be formed on a portion of the lens, for example in the case of a contact lens the spiral may be formed in the optical zone of the lens.

[0026] It will be appreciated that in the case of contact lenses, the lenses will comprise an optical zone that can provide vision correction. Contact lenses and intraocular lenses according to embodiments of the present invention can further comprise a surrounding peripheral zone that does not provide any additional focusing or vision correction. The peripheral zone can only serve to help maintain the contact lens in a fixed position on the wearer's eye. It will be appreciated by those skilled in the art that the surface power map is therefore defined by the variation of the first surface across the optical zone of the lens. Variations of the lens surface outside the optical zone (e.g., within the peripheral zone) are not treated as defining the surface power map in the context of the present invention. Similar considerations apply to intraocular lenses that can further comprise an optical zone and an (optional) peripheral zone.

[0027] The optic zone of a contact lens according to an embodiment of the present invention may have a diameter between 4 mm and 9 mm depending on the type of contact lens. For example, the diameter of the optic zone may be about 5 mm, about 6 mm, about 7 mm, or about 8 mm. The diameter of the optic zone of a contact lens may be between 7 mm and 9 mm. The optic zone has an optical axis corresponding to its geometric center.

[0028] The period of the radial variation (e.g., the radial variation of both the first and second surface power maps) may be greater than 100 microns. The period of the angular variation (e.g., the radial variation of both the first and second surface power maps) may be greater than 6 degrees.

[0029] In the first and / or second surface power maps, one or both of the radial and angular variations are of constant magnitude across the power maps.

[0030] The period of the radial variation may be greater than 200 microns, preferably greater than 400 microns, more preferably greater than 800 microns. The period of the angular variation may be greater than 6 degrees, preferably greater than 9 degrees, preferably greater than 18 degrees, more preferably greater than 36 degrees. The period of the radial variation may be between 0.1 mm and 10 mm. The period of the radial variation may be between 0.5 mm and 5 mm. The period of the radial variation may be between 1 mm and 2 mm.

[0031] The period of the angular variation may be less than 180 degrees, preferably less than 90 degrees, and more preferably less than 45 degrees. The period of the angular variation may be between 180 degrees and 9 degrees. The period of the angular variation may be between 120 degrees and 24 degrees. The period of the angular variation may be between 90 degrees and 36 degrees. Each of the spirals may include more than two, preferably more than four, and more preferably more than eight arms. It will be appreciated by those skilled in the art that the period of the sinusoidal variation of the angle determines the number of arms on the spiral. Thus, the radial variation may have a period greater than 100 microns, and the angular variation may have a period greater than 6 degrees, preferably greater than 9 degrees, more preferably greater than 18 degrees, and even more preferably greater than 36 degrees. The radial variation may have a period greater than 200 microns, and the angular variation may have a period greater than 6 degrees, preferably greater than 9 degrees, more preferably greater than 18 degrees, and even more preferably greater than 36 degrees. The radial variations may have a period greater than 400 microns and the angular variations may have a period greater than 6 degrees, preferably greater than 9 degrees, more preferably greater than 18 degrees, and even more preferably greater than 36 degrees. The radial variations may have a period greater than 800 microns and the angular variations may have a period greater than 6 degrees, preferably greater than 9 degrees, more preferably greater than 18 degrees, and even more preferably greater than 36 degrees. It will be appreciated that the above applies to either surface of the lens.

[0032] The spiral formed on the first surface power map and the spiral formed on the second surface power map may twist in opposite directions but may otherwise be substantially identical.

[0033] The power can vary smoothly across the power map. The power can vary continuously without any discontinuities. The power can vary at a rate of variation of less than 80 D / mm, preferably less than 40 D / mm, more preferably less than 20 D / mm across the aforementioned portion. The surface can vary smoothly across the portion. The surface can vary continuously without any discontinuities. A smooth variation of the power across the power map can result in a lens surface profile that is easier to manufacture using a lathe. It will be appreciated by those skilled in the art that manufacturing an ophthalmic lens using a lathe can include using a lathe to mold one or more surfaces of a lens (e.g., a contact lens), a mold for a lens (e.g., a mold for a contact lens), and an insert for a lens mold (e.g., an insert for a contact lens mold). Sharp transitions and features can be difficult to achieve using a lathe. Thus, lenses with such features with desired or required definitions often cannot be reproduced when manufactured using a lathe. It will therefore be appreciated that the term smooth in this context also means sufficiently smooth to permit the desired shaping of a surface of a lens, a mold for a lens, or an insert for a lens mold using a lathe.

[0034] The power map may vary as a square wave in one or both of the radial and angular directions. The power map may vary as a rounded square wave in one or both of the radial and angular directions. The power map may vary as a sine wave in one or both of the radial and angular directions.

[0035] Radial and angular variations may be associated with each waveform. In addition, the power maps of these waveforms may be symmetric with a substantially equal balance between near defocus and distance vision correction. Alternatively, the power maps may be biased toward either vision correction or near defocus. Thus, the power maps of these waveforms may be asymmetric in one or both of the radial and angular directions.

[0036] The period of one or both of the radial and angular variations may be substantially constant across the power map.Embodiments of the invention in which the radial and angular variations are substantially constant provide lenses with surface profiles that are easy to manufacture using a lathe.

[0037] The period of one or both of the radial and angular variations can vary with either or both of the radial distance from and angular position about the optical axis of the lens. Embodiments of the invention in which the period of one or both of the radial and angular variations varies with position on the lens can provide lenses in which the properties of the helix (e.g., the twist rate or arm width of the helix) vary within various regions of the optical zone. It will be appreciated that the optical axis of a contact lens is also approximately the center of the optical zone of the contact lens.

[0038] The variations in period of radial variation can be separated, for example, by a blended region of linearly varying lens power. Such a blended region can comprise concentric rings of linearly varying period between a first region having a first period of radial variation and a second region having a second period of radial variation. Thus, the blended region can provide a smooth transition between regions of radial variation of different periods. The regions of radial variation of different periods may be separated by two blended regions and an intervening region of substantially constant lens power. The blended region can have a width (in plan view) of about 25 micrometers to about 200 micrometers.

[0039] Each arm of one or both of the helices may twist through between a quarter turn and 40 turns. It will be appreciated by those skilled in the art that the number of turns that a helix arm twists through is determined by the period of the radial variation and the radius of the surface power map.

[0040] The ratio of the period of radial variation to the period of angular variation may be greater than 0.1 mm:6°. Each arm of one or both of the spirals may be greater than 0.1 mm, preferably greater than 0.5 mm, more preferably greater than 1 mm. Each may be between 0.1 mm and 3 mm in width. Each arm may be between 0.25 mm and 2 mm in width. Each arm may be between 0.5 mm and 1 mm in width. It will be appreciated by those skilled in the art that the width of an arm at a given radius is defined as the perpendicular width of the arm (i.e., the width in a direction perpendicular to the given radius). The width of an arm is defined in this context as the distance between two points immediately adjacent to each side of the arm, both of which have either a maximum or minimum gradient, and which bracket a degree undergoing a single positive or negative deflection. It will be appreciated by those skilled in the art that such a definition of width gives a linear measurement of the arm width along a tangential to a circle of a given radius. Moreover, it will be appreciated by those skilled in the art that a width measurement under this definition will differ from a width measurement of an arm taken as an arc of a circle having a given radius. Unlike width measurements under a linear width definition, such an arc-based measurement is considered to be proportional to the angular period. The magnitude of the difference between the widths obtained by these two methods will depend on the angular period of the particular case at hand.

[0041] Each of the spirals may comprise more than two arms, preferably more than four arms, more preferably more than eight arms, and even more preferably more than 16 arms.

[0042] Each of the arms of the helix can twist through at least half a turn, preferably at least one turn, more preferably at least one and a half turns, and even more preferably at least two turns.

[0043] Each arm of the spiral may extend from the optical axis of the portion to the periphery of the power map. A contact lens according to an embodiment of the present invention in which the arms of the spiral extend from the optical axis of the lens to the periphery of the power map can provide a substantially constant ratio of the first lens power (corresponding to distance vision accommodation) to the second lens power (corresponding to myopic defocus) in the presence of varying pupil dilation. Such an embodiment can provide a more consistent myopic defocus image under varying light conditions compared to a concentric ring lens design. When the ophthalmic lens is a contact lens, the myopic defocus image may be more consistent upon decentration of the lens compared to a concentric ring contact lens design. When the ophthalmic lens is a spectacle lens, the myopic defocus image may be more consistent upon eye rotation compared to other spectacle lens designs.

[0044] It will be appreciated that the lens will have an average lens power. It will further be appreciated that the lens will be divided between a first zone of the lens having a lens power greater than the average and a second zone of the lens having a lens power less than the average. The ratio of the first zone to the second zone may be 10:1 and 1:10. The ratio of the first zone to the second zone may be 5:1 and 1:5. The ratio of the first zone to the second zone may be 3:1 and 1:3. The ratio of the first zone to the second zone may be 2:1 and 1:2. The ratio of the first zone to the second zone may be approximately 1:1.

[0045] The power map may include a central region and an outer region. The central region may immediately surround the optical axis of the lens. The outer region may immediately surround the central region. The power of the central region may not vary periodically across the central region. The outer region may include a helical power profile. Thus, the outer region may include angular and radial variations in the power of the first and / or second surface power maps. The helix may be formed in the central region. In such cases, the helix may not extend into the outer region. Alternatively, the helix may be formed in the outer region. In such cases, the helix may not extend into the central region. Alternatively, the central region may include a helical power profile and the outer region may not vary periodically (e.g., be substantially constant) across the outer region. The non-varying region of the lens may provide vision correction, for example, by providing a power for myopia correction (i.e., providing clear distance vision). Alternatively, the non-variable regions of the lens may provide portions of the lens that do not provide any vision correction and therefore simply allow for normal accommodative vision. Providing a contact lens in which the central or outer regions have a lens power that is free of cyclic power fluctuations can enable the lens to provide simultaneous myopia control and correction.

[0046] Thus, one or more portions of the lens may be arranged to provide a function other than myopia control. For example, a central region of the lens may have a lens power selected to provide vision correction, e.g., myopia correction. It will be appreciated that such regions of the lens may be arranged to provide any type of vision correction that can be provided by known contact and spectacle lenses. Thus, the spiral formed by the first and second surface power maps may be present only in one or more specific myopia control portions of the lens. Such portions of the lens may take any shape that projects radially outward from the center of the lens, e.g., one or more of annular rings, strips, or alternating portions of a pseudo-dartboard pattern. The spiral power profile formed by the first and second surface power maps may be interrupted by annular ring-shaped portions of corrective lens power at a predetermined radial distance from the optical axis of the lens. The lens may comprise a plurality of such corrective ring portions. The spiral power profile may continue between the corrective ring portions.

[0047] Contact lenses according to embodiments of the present invention may include a surrounding peripheral zone which does not provide any additional focusing or vision correction and serves only to help maintain the contact lens in place on the wearer's eye.

[0048] In a conventional manner, when worn on the eye, the contact lens rests on the cornea and the optical zone substantially encompasses the wearer's pupil. In this case, the diameter of the central region may be less than 50% of the diameter of the power map, preferably less than 40%, and more preferably less than 30%. The central region may be smaller than the minimum pupil size of the wearer of the contact lens. Such an embodiment of the invention may provide a central region smaller than the minimum pupil size of the wearer. An embodiment of the invention having a central region smaller than the minimum pupil size of the wearer may maintain vision correction in the presence of changing light conditions.

[0049] The lens may include a transition region. The transition region may surround the central region. The outer region may surround the transition region. The power of the transition region may vary to provide a smooth transition between the central region and the outer region. An embodiment of the present invention that provides a smooth transition between the central region and the outer region may allow easier lathe manufacture of lenses, molds for such lenses, and inserts for such lens molds. In this case, it will be appreciated by those skilled in the art that "smooth" in this context means that the lens profile must be smooth enough to be produced using a lathe. The transition region may also vary as a spiral, for example as an extension of a spiral formed in the outer region. In such an embodiment, the magnitude of the spiral formed in the transition region may decay (e.g., linearly) between the outermost radius of the transition region and the innermost radius of the transition region. The transition spiral may decay from a magnitude equal to that of the spiral formed in the outer region (e.g., at the outermost radius) to zero (e.g., at the innermost radius).

[0050] The period and phase of the radial and angular variations of the second surface power map may be the same as the first surface power map. Thus, the spirals provided by the first surface power map and the second surface power map may be the same except for the opposite twisting directions. By providing first and second surface power maps with counter-rotating spirals, a lens power map that approximates a dartboard pattern of alternating annular rings can be provided. It will be appreciated by those skilled in the art that the lens power map is formed by the superposition of the power maps of the first and second surface power maps. It will also be appreciated that a pseudo-dartboard pattern is thus provided by the combination of the first surface power map and the second power map, each of which retains the ease of manufacture advantages discussed above. Such an embodiment may thus allow for easier manufacturing of lenses with a pseudo-dartboard power map using a lathe.

[0051] The lens power map can include multiple sections. The multiple sections can provide either a first power corresponding to a desired vision correction or a second power corresponding to a desired myopic defocus. Thus, the first power can be between 0 diopters (D) and -10D. The first power can be from -0.25D to -6.00D. The second power provided in the lens of the present invention can be stronger than the first power of the lens, for example, the second power can be 1D to 5D stronger than the first power. The second power can be 1D to 4D stronger than the first power. The second power can be 1D to 5D stronger than the first power. The second power may vary, as occurs when providing discrete defocus segments with stronger powers than the first power, such that some of the above-mentioned segments may have a second power of +1D, some segments may have a second power of +2D, and some segments may have a second power of +3D. The variation in the second power may occur within the same arm or may occur within different arms. These sections may be arranged on the lens to alternate radially and / or angularly between the first and second powers.

[0052] Contact lenses according to embodiments of the present invention may include a ballast to determine the orientation of the lens when placed on the wearer's eye. The contact lens may provide a particular advantage to the wearer in a given orientation. An embodiment of the present invention incorporating a ballast into the contact lens will rotate to a predetermined rest 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 result from the action of the eyelid on the wedge. By placing the ballast within the contact lens, it is possible to ensure that this rest angle corresponds to an orientation of the lens that provides a particular advantage to the wearer.

[0053] The present invention provides, according to a second aspect, a method of manufacturing an ophthalmic lens (e.g., a contact lens) for myopia control. The method comprises operating a lathe to shape first and second surfaces of one of a lens (e.g., a contact lens), a mold for a lens (e.g., a mold for a contact lens), or an insert for manufacturing a mold for a lens (e.g., an insert for a mold for a contact lens). The first surface forms a first surface power map. The second surface forms a second surface power map. Each of the first and second surface power maps comprises a helix. The helix formed by the first surface power map and the helix formed by the second surface power map twist in opposite directions.

[0054] Each of the helices may be formed by substantially periodically varying the power of the respective surface both radially outward from the optical axis of the lens and angularly about the optical axis.

[0055] The method may comprise operating a lathe to shape the surface of the lens. Alternatively or additionally, the method may include operating a lathe to shape the surface of a mold for the lens. Alternatively or additionally, the method may include operating a lathe to shape the surface of an insert for the manufacture of a mold for the lens. It will be appreciated by those skilled in the art that the more the object of lathe shaping is removed from the lens, the less the definition of the features that will be reproduced on the resulting lens. Thus, for example, shaping the surface of the lens using a lathe allows the surface of the mold for the lens to be defined with more surface features than would be achievable when shaping using a lathe.

[0056] In embodiments of the invention where the lens is a contact lens or an intraocular lens, the first and second surface power maps may be formed by molding the optical zones of the first and second surfaces. It will be appreciated that the optical zone of a mold or an insert for a mold refers to the portion of the mold that corresponds to the optical zone of a contact lens manufactured using that mold or insert.

[0057] Lenses, e.g., contact lenses, according to the present invention can be formed by a cast molding process, a spin casting process, or a lathing process, or a combination thereof. As will be understood by those skilled in the art, cast molding refers to the molding of lens members by placing a lens-forming material between a female mold member having a concave lens member-forming surface and a male mold member having a convex lens member-forming surface.

[0058] In embodiments where the ophthalmic lens comprises a contact lens, the contact lens material is visually clear (although it may include handling tinting) when used as a portion of the contact lens or as the entire contact lens. The contact lens material may be a hydrogel material, a silicone hydrogel material, or a silicone elastomer material, as understood in the art. In other words, the contact lens of the present invention can comprise, consist essentially of, or consist of a hydrogel material, a silicone hydrogel material, or a silicone elastomer material. As understood in the contact lens field, a hydrogel is a material that retains water in an equilibrium state and is absent of silicone-containing chemicals. A silicone hydrogel is a hydrogel that includes silicone-containing chemicals. The hydrogel and silicone hydrogel materials used herein have an equilibrium water content (EWC) of at least 10% to about 90% (wt / wt). The hydrogel or silicone hydrogel material can have an EWC of about 30% to about 70% (wt / wt). In comparison, the silicone elastomer materials used herein have a water content of about 0% to less than 10% (wt / wt). Typically, the silicone elastomer materials used with the method or device of the present invention have a water content of 0.1% to 3% (wt / wt). Alternatively, examples of contact lenses of the present invention can be made from a rigid gas-permeable material such as polymethylmethacrylate (PMMA).

[0059] The method can include forming a contact lens in a molding assembly that includes a first mold part and a second mold part assembled together. In the case of a hydrogel lens or a silicone hydrogel lens, the lens can be produced by polymerizing a hydrogel or silicone hydrogel lens formulation with a polymerization initiator in a lens-shaped cavity formed between the first and second mold parts. In the case of a silicone elastomer lens, the lens can be produced by curing, vulcanizing, or catalyzing the reaction of a liquid silicone elastomer material in a lens-shaped cavity formed between the first and second mold parts, such as by hydrosilylation. The surface of each mold part that forms the contact lens-shaped cavity can be convex, concave, flat, or a combination thereof. After the contact lens is formed, the two mold parts are separated such that the contact lens remains attached to one surface of the mold parts. As a result, a contact lens is provided on the surface of the first or second mold part. It may be desirable to place the lens member on a face of a mold part that was not used to produce the first lens member, but this may require additional steps to achieve the desired alignment of the member relative to the mold part. The lenses can then be removed from the attached mold part and further processed, such as by extraction and hydration, inspected, packaged, and sterilized.

[0060] FIG. 1 shows a contact lens 10 according to an embodiment of the present invention. The contact lens 10 comprises an optical zone 11 and a peripheral zone 13. The optical zone 11 comprises the portion of the lens through which the wearer of the contact lens sees. The optical zone 11 forms a lens designed to provide vision correction to the wearer. The peripheral zone 13 surrounds the optical zone 11 and does not provide any vision correction to the wearer. The peripheral zone 13 can perform other functions. For example, the peripheral zone 13 can function to help maintain the contact lens on the wearer's eye. The peripheral zone 13 can include a ballast to maintain a predetermined orientation of the contact lens on the wearer's eye.

[0061] The two surfaces of the contact lens are shaped to vary across the optical zone 11 to form a first and a second surface power map. The first and second surface power maps together form a lens power map. Thus, the optical zone can be said to provide a first surface power map, a second surface power map, and a lens power map. Within the optical zone, the power map can include one or more distinct regions. The exemplary contact lens shown in FIG. 1 comprises a central region 15, an outer region 17, and a transition region 19. The outer region 17 surrounds the transition region 19. The transition region 19 surrounds the central region 15. The central region 15 and the outer region 17 can provide different lens power arrangements to provide different vision corrections. The transition region 19 can function to provide a smooth transition between the central region 15 and the outer region 17. It will be appreciated that the contact lens shown in FIG. 1 is provided by way of example only, and other contact lenses according to the invention can include more or fewer regions. For example, contact lenses according to embodiments of the present invention may exclude a transition region, or may even include only a single region throughout the optical zone 11. Contact lenses according to embodiments of the present invention may include additional regions, for example, formed as concentric circles.

[0062] In accordance with a first exemplary embodiment of the present invention, a contact lens for myopia control is provided. It will be appreciated that alternative embodiments may comprise an intraocular lens or a spectacle lens. The contact lens comprises a first surface and a second surface. In this exemplary embodiment, the first surface comprises an outer surface of the contact lens and the second surface comprises an inner surface of the contact lens. It will be appreciated by one of ordinary skill in the art that the outer surface is a convex surface of the contact lens adjacent a wearer's eyelid and the inner surface is a concave surface of the contact lens adjacent a wearer's eyeball.

[0063] The first surface is shaped to form a first surface power map. In this exemplary embodiment, the first surface power map is formed by only a portion of the first surface. This portion of the first surface is in this case defined by and corresponds to the optical zone of the contact lens. It can therefore be said that the first surface power map is given by the variation of the first surface in the optical zone.

[0064] The optical zone of the contact lens provides any vision correction by the lens. The contact lens according to the embodiment of the present invention may further comprise a surrounding peripheral zone that does not provide any additional focusing or vision correction. In such a contact lens, the peripheral zone may only serve to help maintain the contact lens in a fixed position on the wearer's eye. Thus, it will be appreciated by those skilled in the art that in such an embodiment, the first surface power map is defined by the variation of the first surface across the optical zone of the lens. Similarly, the second surface power map is defined by the variation of the second surface across the optical zone. Variations of the lens surface outside the optical zone (e.g., within the peripheral zone) do not affect the surface power map in these embodiments.

[0065] It will be appreciated that the first surface power map indicates the modification provided by the shape of this surface to the overall contact lens power map. Thus, a contact lens having two surfaces (an inner and an outer surface) will have two surface power maps, the combination of which determines the overall contact lens power map.

[0066] FIG. 2 shows a first surface power map 100. The first surface power map 100 forms a spiral. The spiral comprises a plurality of arms 101 (four in this example). Each of the arms 101 comprises one of a peak arm 101a and a trough arm 101b. It will be appreciated that the peak arm 101a is the arm with a positive deviation from the average power of the surface power map (or the periodically varying region of the surface power map) and the trough arm 101b is the arm with a negative deviation from the average power of the surface power map (or the periodically varying region of the surface power map). The spiral is formed by substantially periodically varying the power both radially outward from the optical axis of the contact lens and angularly around the optical axis. It will be appreciated that the optical axis of the contact lens corresponds to the optical axis of the optical zone of the contact lens. The power varies between a first lens power and a second lens power. The first surface power map in this exemplary embodiment has a base lens power of -3.0 D with an add power of +3.0 D. Thus, the first lens power is -3.0 D and the second lens power is +0 D. It will be appreciated by those skilled in the art that the specific values ​​of the first and second lens powers (and thus the base lens powers and add powers) provided are merely examples, and that the actual values ​​used in a given context will be dictated by the needs of the intended wearer.

[0067] In this exemplary embodiment, the period of the radial variation is 1.2 mm and the period of the angular variation is 90 degrees. However, it will be appreciated that other periods of radial and / or angular variation may be used in alternative embodiments. The period of the radial variation need only be greater than 100 microns and the period of the angular variation need only be greater than 6 degrees.

[0068] In this particular embodiment, the power varies smoothly in both radial and angular directions across the first surface power map 100 in a substantially sinusoidal manner. Having the surface power map vary smoothly across the first surface power map allows for easier manufacturing using a contact lens lathe or an apparatus for manufacturing contact lenses (e.g., a mold or an insert for a mold). However, in alternative embodiments, the power can vary according to other waveforms. For example, the power can vary as a square wave or a rounded square wave in one or both of the radial and angular directions. Thus, in alternative embodiments, the power does not necessarily vary smoothly across the first surface power map.

[0069] In this exemplary embodiment, the positive and negative excursions of the sine wave are of equal length such that the sine wave can be said to have a 50% duty cycle. Alternative embodiments include variations having other duty cycles. Thus, in such embodiments, the positive excursion may be of a different length than the negative excursion.

[0070] It will be appreciated that the width of the helix arms 101 is determined at least in part by the ratio of the period of radial variation to the period of angular variation. In this exemplary embodiment, each helix arm 101 is approximately 500 microns in width. It will be appreciated that alternative embodiments may incorporate arms 101 having different widths. Similarly, it will be appreciated that the width of an arm 101 is defined as its perpendicular width.

[0071] Similarly, in this exemplary embodiment, the period of the radial and angular variations are each substantially constant across the first surface power map, but in alternative embodiments, the period of at least one of the radial and angular variations can vary according to one or both of the radial distance from the optical axis of the lens and the angular position about the optical axis of the lens.

[0072] In alternative embodiments, the period of the angular variation is less than 180°. It will be appreciated by those skilled in the art that the period of the angular variation determines the number of arms 101 on the helix. Thus, in such an embodiment, the helix comprises at least two arms. It will also be appreciated that certain values ​​of angular variation, particularly those that are unit fractions of 360°, can be particularly advantageous in providing a surface power profile that does not have angular discontinuities.

[0073] In this exemplary embodiment, each arm 101 of the spiral twists through an angle of 270 degrees (or 0.75 turns). In alternative embodiments of the invention, each arm 101 of the spiral can twist through between a quarter turn (90 degrees) and 40 turns.

[0074] In this particular embodiment, the first surface power map 100 comprises a central region 103 and an outer region 105. The central region 103 immediately surrounds the optical axis of the contact lens. The outer region 105 surrounds the central region 103. The power of the central region 103 does not vary periodically across this region, e.g., may be substantially constant. The outer region 105 comprises a helical power profile, and thus comprises angular and radial variations in power.

[0075] In an alternative embodiment of the invention, the central region includes a helical power profile and the outer region does not vary periodically throughout itself (e.g., the outer region can have a substantially constant lens power). In another alternative embodiment of the invention, each arm 101 of the helix extends from the center of the first surface power map to the periphery of the first surface power map. Thus, such an embodiment does not include distinct central and outer regions.

[0076] In this exemplary embodiment, the central region 103 has a diameter of 2 mm, which corresponds to 25% of the 8 mm diameter of the power map. In this exemplary embodiment, the power map corresponds to the optical zone of the contact lens. The optical zone through which the wearer sees thus provides the first surface power map 100 shown in FIG. 2. In addition, the contact lens may include a surrounding peripheral zone that does not provide additional focusing or vision corrections, but serves only to help maintain the contact lens in place on the wearer's eye. In other embodiments, the diameter of the central region may be less than 25% of the diameter of the power map (or optical zone). However, it will be appreciated that in alternative embodiments of the invention, the diameter of the central region 103 may take other values. Similarly, it will be appreciated that the ratio of the diameter of the central region 103 to the diameter of the power map may take other values. For example, the diameter of the central region 103 may be less than 30% of the diameter of the power map (or optical zone).

[0077] In an embodiment, the central region 103 may be smaller than the minimum pupil size of the wearer of the contact lens. Such an embodiment maintains effective myopia control even when the wearer's pupil is constricted to its minimum size. If the central region 103 is larger than the minimum pupil size, then only the central region 103 will be positioned over the wearer's entrance pupil when the wearer's pupil is constricted to its minimum size. Since the power of the central region 103 does not vary as a spiral over this region, the lens may not provide effective myopia control for any pupil size smaller than the central region 103. It will be appreciated that in eyeglasses according to embodiments of the present invention, the wearer's eye can move independently of the lens. Thus, such lenses can provide effective myopia control despite this independent movement when the central region is smaller than the wearer's minimum pupil size.

[0078] This exemplary embodiment further comprises a transition region 107. The transition region 107 surrounds the central region 103. The outer region 105 surrounds the transition region 107. The power of the transition region 107 varies to provide a smooth transition between the central region 103 and the outer region 105. It will be appreciated that such a transition region 107 is not required, and thus alternative embodiments do not include the transition region 107. It will be appreciated that "smooth" in this context is defined as being smooth enough that the corresponding lens curvature can be reproduced by a lathe. In this exemplary embodiment, the transition region is approximately 300 microns in width. However, it will be appreciated that transition regions of other widths can be used.

[0079] It will be appreciated by those skilled in the art that the second surface of the contact lens forms a second surface power map. The second surface power map is also provided by only a portion of the second surface that also corresponds to the optical zone of the contact lens. The second surface power map 200 (FIG. 3) also varies substantially periodically both angularly around the optical axis of the lens and radially outward from the optical axis. Thus, the second surface power map 200 also comprises a spiral. As with the first surface, the spiral also comprises a number of arms 201, including peak arms 201a and trough arms 201b. In this exemplary embodiment, the period of the radial and angular variations of the second surface power map 200 is the same as the first surface power map 100. However, it will be appreciated by those skilled in the art that alternative embodiments can incorporate variations on the second surface power map 200 having a different period than one or both of the periods of the first surface power map 100. The period of angular variation of the second surface power map 200 may be greater than 6 degrees. Similarly, in an alternative embodiment, the period of radial variation of the second surface power map 200 may be greater than 100 microns. In this exemplary embodiment, the second surface power map 200 also comprises a central region 203, an outer region 205, and a transition region 207.

[0080] The spiral formed by the second surface power map 200 twists in the opposite direction to the spiral formed by the first surface power map 100. Thus, in this particular embodiment, the spiral provided by the first surface power map 100 and the spiral provided by the second surface power map 200 may be the same except for the opposite twist directions. The power map of the contact lens is determined by the superposition of the power map of the first surface power map 100 and the power map of the second surface power map 200. Figure 4 shows the total lens power map of the contact lens of the first embodiment.

[0081] The superposition of the two counter-rotating spirals formed by the first surface power map 100 and the second surface power map 200 results in a lens power map that approximates a pseudo-dartboard pattern of annular rings of alternating segments. The lens power approximately alternates both radially and angularly between the first and second lens powers. Because the power alternates angularly between the first and second lens powers, the contact lens also provides a monotonic variation in the ratio of the first lens power to the second lens power as the wearer's pupil constricts. Thus, the contact lens 300 also provides a more constant ratio of lens power providing near defocus to lens power providing distance vision accommodation under variable light conditions.

[0082] Because both the first surface power map 100 and the second surface power map 200 include a central region, an outer region, and a transition region, the overall lens power map of the contact lens 300 also comprises a central region 303, an outer region 305, and a transition region 307.

[0083] FIG. 5 shows a contact lens according to a second embodiment of the present invention. The second embodiment is substantially the same as the first embodiment, except that the spiral provided by the second surface power map is rotated through a phase shift of 45 degrees. As can be seen from FIG. 5, the superposition of the first and second surface power maps with two counter-rotating spirals results in a pseudo-dartboard power map similar to the second embodiment. Thus, the superposition of the two counter-rotating spirals results in a dartboard lens power map regardless of the relative phase of the first and second spirals. Again, the overall lens power map of the contact lens 400 comprises a central region 403, an outer region 405, and a transition region 407.

[0084] FIG. 7 shows a spectacle lens 700 according to a third embodiment of the invention. The spectacle lens comprises first and second surfaces providing substantially the same first and second surface power maps as described with respect to the first embodiment of the invention. However, it will be appreciated by those skilled in the art that the spectacle lens does not include an optical zone in the same sense as the contact lens of the first embodiment. Thus, in this case, the first and second surface power maps are provided by at least a portion of the spectacle lens, for example substantially all of the spectacle lens. It will be appreciated that alternative embodiments of the invention comprise spectacle lenses having substantially the same surface power profile as described with respect to the second embodiment of the invention. The spectacle lens 700 comprises a central region 715, an outer region 717, and a transition region 719. In this exemplary embodiment, the spiral formed by the first and second surface power maps does not extend to the leftmost edge of the spectacle lens 717. Instead, the spiral extends only to the dashed line 701. The spiral may decay in magnitude (e.g., linearly) from the boundary between the transition region 719 and the outer region 717 as it extends outward to the dashed line 701. In other embodiments, the spiral may have a substantially constant magnitude across the outer region 717. In such embodiments, the eyeglass lens 700 may further comprise a narrow blend region extending along the dashed line 701. It will be further appreciated that in other embodiments, the spiral continues outward to the edge of the eyeglass lens 700. In this exemplary embodiment, the central region 715 (and the transition region 719 and outer region 717 surrounding it) is not positioned at the geometric center of the eyeglass lens 700, but can be said to be offset from the geometric center of the eyeglass lens 700. It will be appreciated by those skilled in the art that such an offset can serve to place the central region in a portion of the eyeglass lens 700 through which the wearer most often gazes.

[0085] According to a fourth embodiment of the present invention there is provided an intraocular lens comprising first and second surfaces providing first and second surface power maps substantially the same as described with respect to the first embodiment of the present invention. It will be appreciated that alternative embodiments of the present invention comprise intraocular lenses having substantially the same surface power profiles as described with respect to the second embodiment of the present invention.

[0086] FIG. 6 shows a flow diagram illustrating steps of a method 500 for manufacturing a lens, for example a contact lens, according to a fifth embodiment of the present invention.

[0087] The first step of method 500, represented by element 501, comprises operating a lathe to shape a first surface of one of a lens, a mold for a lens, or an insert for manufacturing a mold for a lens. The first surface is shaped to form a first surface power map. The first surface power map comprises a spiral. The surface may be shaped to vary substantially periodically both radially outward from and angularly about an optical axis of the contact lens.

[0088] A second step of method 500, represented by element 503, comprises operating a lathe to shape a second surface of the lens, mold, or insert. The second surface is shaped to form a second surface power map. The second surface power map comprises a spiral. The second surface may be shaped to vary substantially periodically both radially outward from and angularly about the optical axis of the contact lens. The second surface is shaped such that the spiral formed by the first surface power map twists in an opposite direction to the spiral formed by the second surface power map.

[0089] When the first and second surfaces are included on a mold for a lens or an insert for a mold for a lens, method 500 can include an optional third step represented by element 505. The third step 505 comprises manufacturing a lens using the mold of the insert for the mold for the lens.

[0090] Although the invention has been described and illustrated with reference to specific embodiments, it will be appreciated by those skilled in the art that the invention is susceptible to many different variations not specifically exemplified herein. By way of example only, certain possible variations are now described below.

[0091] In both the first and second embodiments, each of the surface power maps of the contact lens comprises a central region having a substantially constant power, an outer region incorporating a helical power profile, and a transition region providing a smooth transition between the central and outer regions. However, some alternative embodiments do not incorporate a transition region. Yet other alternative embodiments do not incorporate distinct central and outer regions. Instead, in such embodiments, the helical profile extends all the way from the center of each of the surface power maps to a radial surrounding zone of the surface power map.

[0092] In the first and second embodiments, the spiral formed on the first surface power map twists in a counterclockwise direction and the spiral formed on the second surface power map twists in a clockwise direction, however, in an alternative embodiment, the spiral formed on the first surface power map twists in a clockwise direction and the spiral formed on the second surface power map twists in a counterclockwise direction.

[0093] In some embodiments of the present invention, the spiral formed on one or both of the first and second surface power maps changes rotation direction at a predetermined radial distance from the optical axis of the lens. For example, the spiral can rotate clockwise between the optical axis of the lens and a predetermined radial distance, and counterclockwise beyond the predetermined radial distance. The lens can incorporate more than one variation in the rotation direction of the spiral. Thus, the spiral can change, for example, from clockwise to counterclockwise and then back to clockwise again. It will be appreciated by those skilled in the art that the lens can incorporate any number of spiral rotation direction changes. It will also be appreciated that each of these direction changes may occur at any selected radial distance from the optical axis of the lens. Thus, the power map can comprise annular rings that alternate between clockwise and counterclockwise rotating spirals. In such an embodiment, each counter-rotating spiral may change rotation direction at the same radial distance from the optical axis of the lens.

[0094] In some embodiments, between the regions of the ophthalmic lens having different rotation directions, there can be a region where the power map does not change as a spiral. For example, this region can have a substantially constant power. For example, from the center of the lens to a first radial distance, the lens can change as a clockwise spiral, followed by a region of substantially constant power, and then change as a counterclockwise spiral. Thus, the power map can appear to include, for example, a plurality of annular rings that alternate between a spiral power and a substantially constant power, and the spiral region also alternates between a clockwise rotation and a counterclockwise rotation.

[0095] Similarly, in some embodiments, the spiral can be interrupted by one or more regions, e.g., rings, where the power map does not change as the spiral. Such regions can have a substantially constant power. Thus, for example, the power map can comprise annular rings that alternate between a spiral power and a substantially constant power. In such embodiments, the spiral can change rotational direction between each interruption, or can continue in the previous rotational direction. Thus, the spiral can maintain a constant rotational direction across the lens, but may be interrupted by regions of substantially constant lens power.

[0096] Although embodiments of the present invention have been described above with respect to methods of manufacturing contact lenses, molds for contact lenses, or inserts for molds for contact lenses using a lathe, it will be appreciated that other manufacturing methods are possible. For example, the molds or inserts may be manufactured using additive manufacturing techniques, such as by 3D printing.

[0097] Wherever the above description refers to an integer or element having a known, obvious or foreseeable equivalent, such equivalent is incorporated herein as if it were individually set forth. Reference should be made to the claims to determine the true scope of the invention, which should be interpreted as including all such equivalents. Similarly, it will be recognized by the reader that integers or features of the invention described as being preferred, advantageous, convenient, etc. are optional and do not limit the scope of the independent claims. It is further to be understood that such optional integers or features, while being possible benefits in some embodiments of the invention, may be undesirable in other embodiments and therefore may be absent. [Explanation of symbols]

[0098] 300 Contact Lenses 303 Central area 305 Outer area 307 Transition Zone

Claims

1. An ophthalmic lens for inhibiting the progression of myopia, comprising: an outer surface that is convex and shaped to form a first surface power map; and an inner surface that is concave and shaped to form a second surface power map, the first surface power map comprises a spiral; the second surface power map comprises a spiral; the spiral formed by the second surface power map is twisted in an opposite direction to the spiral formed by the first surface power map; An ophthalmic lens characterized by:

2. 2. The ophthalmic lens according to claim 1, wherein the lens is a contact lens or a spectacle lens.

3. An ophthalmic lens as described in claim 1 or claim 2, characterized in that the powers of the inner and outer surfaces vary continuously across the first and second surface power maps.

4. 4. An ophthalmic lens as claimed in claim 3, wherein the powers of the inner and outer surfaces vary both radially and angularly as a rounded square wave or a sine wave.

5. 5. An ophthalmic lens as claimed in any one of claims 1 to 4, characterized in that each of the first and second surface power maps has a power that varies periodically both radially outward from the optical axis of the lens and in an angular direction around the optical axis of the lens.

6. An ophthalmic lens as described in Claim 5, characterized in that the period of the power that changes periodically radially outward from the optical axis of the lens and the period of the power that changes periodically in an angular direction around the optical axis of the lens are each constant across the first and second surface power maps.

7. An ophthalmic lens as described in claim 5, characterized in that one or more of the periods of the power that change periodically radially outward from the optical axis of the lens and the periods of the power that change periodically in an angular direction around the optical axis of the lens change according to one or both of the radial distance from the optical axis of the lens and the angular position of the lens about the optical axis.

8. The period of the power that varies periodically radially outward from the optical axis of the lens has a period greater than 100 microns; The period of the power that varies periodically in an angular direction about the optical axis of the lens has a period greater than 6 degrees.

8. The ophthalmic lens according to claim 5, wherein the ophthalmic lens is a crystalline lens.

9. An ophthalmic lens according to any one of claims 1 to 8, wherein each spiral comprises at least four arms.

10. 10. An ophthalmic lens according to any one of claims 1 to 9, wherein each arm of each spiral twists through at least half a turn.

11. The lens comprises a central region surrounding an optical axis of the lens and an outer region surrounding the central region; the helix is ​​formed in the outer region; the spiral does not extend into the central region; 11. An ophthalmic lens according to any one of claims 1 to 10.

12. The lens comprises a central region surrounding an optical axis of the lens and an outer region surrounding the central region; the spiral is formed within the central region; the helix does not extend into the outer region; 11. An ophthalmic lens according to any one of claims 1 to 10.

13. 13. An ophthalmic lens according to claim 11 or 12, wherein the central region has a diameter that is less than 50% of the diameter of the helix.

14. the lens comprises a transition region, the transition region surrounding the central region, and the outer region surrounding the transition region; the power of the transition region varies to provide a continuous transition between the central region and the outer region; 14. An ophthalmic lens according to any one of claims 11 to 13.

15. 1. A method of manufacturing an ophthalmic lens, comprising: The concave and convex surfaces of one of a lens, a mold for a lens, or a corresponding insert for manufacturing a mold for a lens are the convex surface forms a first surface power map; the concave surface defines a second surface power map; each of the first surface power map and the second surface power map comprises a spiral; and the spiral formed by the second surface power map twists in an opposite direction to the spiral formed by the first surface power map; operating the lathe to form the 23. A method comprising:

16. 1. A method for inhibiting myopia progression in an individual, comprising: providing a multifocal ophthalmic lens according to any one of claims 1 to 14 to an individual in need of inhibition of myopia progression; 23. A method comprising:

17. 10. The ophthalmic lens of claim 1, wherein each spiral comprises a plurality of arms, each of the plurality of arms including a peak arm and a trough arm.

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