Eyeglasses

Abstract

The present invention relates to an ophthalmic lens for preventing or slowing the development or progression of myopia. The lens has a first optical axis. The first surface of the lens is shaped to form a first surface power map. The second surface of the lens is shaped to form a second surface power map. The first surface power map and the second surface power map together form a lens power map. The first surface power map, the second surface power map and one of the lens power maps include: a basic area and a myopia control area. The basic area has a basic power, and the basic area focuses light to a focus located on the first optical axis. The myopia control area includes a spiral shape and focuses light to a plurality of focuses offset from the first optical axis. It also relates to a method for manufacturing such an ophthalmic lens.

Description

Technical Field

[0001] The present invention relates to ophthalmic lenses. More particularly, but not exclusively, the present invention relates to ophthalmic lenses for preventing or slowing the development or progression of myopia. Background Art

[0002] Myopia control lenses are ophthalmic lenses that attempt to control the progression of myopia in the wearer. This is typically achieved by subdividing the ophthalmic lens into a plurality of zones. Zones in a first subset of the plurality of zones have a first lens power corresponding to a first focusing distance (e.g., to correct hyperopic vision of an unfocused eye). Zones in a second subset of the plurality of zones have a second lens power (also referred to as an add power) selected to provide myopic defocus.

[0003] In the case of contact lenses for myopia control, the multiple areas are typically formed as concentric circles centered on the optical axis of the contact lens, wherein the concentric circles are staggered between a first lens power that provides corrected vision and a second lens power that provides myopic defocus. Thus, the power map of a typical multifocal contact lens includes at least two staggered concentric circles of the first and second lens powers. However, in weaker light conditions, the pupil of the wearer's eye will dilate to provide a larger aperture for the incoming light, thereby increasing the amount of light received into the eye and thereby providing improved weak light vision. When conditions become brighter, the pupil will contract to provide a smaller aperture and thereby limit the amount of light received into the eye. As the wearer's pupil dilates and contracts, the number of concentric rings on the contact lens that are positioned across the wearer's entrance pupil will also change. When the pupil dilates, a larger number of concentric rings will be positioned across the wearer's entrance pupil. Similarly, when the pupil contracts, fewer concentric rings will be positioned across the wearer's entrance pupil. Because the concentric rings are staggered between the first lens power (vision correction) and the second lens power (myopic defocus), the amount of the second lens power that provides myopic defocus that is positioned across the wearer's entrance pupil will change as the wearer's pupil contracts and dilates. These changes can impair the ability of the lens to provide effective myopia control. In some cases, the pupil may even contract to the extent that none of the second lens power that provides myopic defocus is positioned across the wearer's entrance pupil, resulting in the lens being unable to provide effective control of myopia progression.

[0004] Furthermore, while these lenses have been found to be beneficial in preventing or slowing the development or progression of myopia, the annular myopic defocus zone can produce undesirable visual side effects. Light incident on the annular myopic defocus zone is focused in front of the retina, and thus diverges from the focal point to form an out-of-focus ring at the retina. As a result, wearers of these lenses may see a ring or "halo" around the image formed on the retina, especially for small bright objects (such as street lamps and car headlights). Again, the wearer may utilize the additional focal point in front of the retina caused by the annular myopic defocus zone to focus on nearby objects, rather than using the eye's natural accommodation (i.e., the eye's natural ability to change focus) to focus on nearby objects; in other words, the wearer may inadvertently use the lens in the same manner as a hyperopia correction lens (i.e., reducing the need for their eye to accommodate), which is undesirable (especially in the case of children).

[0005] Several lens designs have been described for reducing the progression of myopia. MISIGHT (CooperVision) is the first such contact lens to receive regulatory approval in the United States. The MiSight contact lens is a bifocal contact lens that provides a myopic out-of-focus image at both near and far viewing distances. The bifocal design includes a central distance correction zone circumscribed by staggered rings of different optical powers.

[0006] The present invention seeks to alleviate the above mentioned problems.Alternatively or additionally, the present invention seeks to provide an improved ophthalmic lens for preventing or slowing the development or progression of myopia. Summary of the invention

[0007] According to a first aspect, the present invention provides an ophthalmic lens for preventing or slowing the development or progression of myopia. The lens has a first optical axis. The first surface of the lens is shaped to form a first surface power map. The second surface of the lens is shaped to form a second surface power map. The first surface power map and the second surface power map Figure 1 A lens power map is formed together. One of the first surface power map, the second surface power map, and the lens power map includes a basic area and a myopia control area. The basic area focuses light to a focus located on the first optical axis. The myopia control area includes a spiral shape and focuses light to a plurality of focuses offset from the first optical axis.

[0008] Providing a myopia control zone that focuses light to a focal point offset from the first optical axis means that the myopia control zone does not form an on-axis image at the wearer's retina. This image may be used unintentionally by the wearer to avoid the need for their eye to adjust to focus on nearby objects. Therefore, a myopia control zone that focuses light to a focal point offset from the first optical axis may reduce the risk of a wearer of the lens suffering from a reduction in the ability to adjust focus due to long-term wear of the myopia control lens.

[0009] In addition, a contact lens having a myopia control zone in the shape of a spiral can provide a constant ratio of both the lens power that provides myopic defocus and the lens power that provides hyperopic focus across the entire range of diameters that include the spiral. Thus, as the pupil contracts or dilates, a contact lens having a myopia control zone in the shape of a spiral can maintain a substantially constant ratio of hyperopic focus and myopic defocus (where the spiral covers the entire lens) or a monotonically varying ratio (where the spiral covers only a radial sub-portion of the lens). Thus, a contact lens having a myopia control zone in the shape of a spiral reduces the variation in the ratio of myopic defocus to hyperopic focus in the presence of variable lighting conditions. Thus, a contact lens according to an embodiment of the present invention can provide effective myopia control in the presence of different pupil dilations.

[0010] It will be appreciated by those skilled in the art that in the case where the power map changes smoothly, the power map may include other lens powers, not just the first lens power associated with hyperopic vision focus and the second lens power associated with myopic defocus. In this case, the power map may also include a transition zone with lens powers other than the first and second powers. It will be appreciated that this does not affect or diminish the advantage described above of providing a constant and stable variation of the ratio of hyperopic focus and myopic defocus positioned across the wearer's entrance pupil. It will be appreciated by those skilled in the art that in embodiments, this advantage may be attributed to the lens having a myopia control zone in a spiral shape having a composition of lens powers at a given radius that does not change as a function of the radial distance from the optical axis of the lens.

[0011] According to a second aspect of the present invention, a method for manufacturing an ophthalmic lens is also provided. The method includes operating a lathe to shape a first surface of at least one of the following: a lens, a mold for a lens, or an insert for manufacturing a mold for a lens. The method further includes operating a lathe to shape a second surface of the lens, mold, or insert to form a second surface power map. The combination of the first surface power map and the second surface power map forms a lens power map having a first optical axis. One of the first surface power map, the second surface power map, and the lens power map includes a basic area and a myopia control area. The basic area focuses light to a focus located on the first optical axis. The myopia control area includes a spiral shape and focuses light to a plurality of focuses offset from the first optical axis.

[0012] According to a third aspect of the present invention, there is also provided a method of preventing or slowing the development or progression of myopia in a person. The method comprises providing the person with an ophthalmic lens according to the first aspect.

[0013] It will of course be appreciated that features described in relation to one aspect of the invention may be incorporated into other aspects of the invention. For example, the method of the invention may incorporate any features described with reference to the apparatus of the invention and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings, in which:

[0015] Figure 1 A schematic plan view showing a contact lens according to an exemplary embodiment of the present invention;

[0016] Figure 2 shows a schematic cross-sectional view of a section of a contact lens according to a first embodiment of the present invention;

[0017] Figure 3 shows a schematic cross-sectional view of a section of a contact lens according to a second embodiment of the present invention;

[0018] Figure 4 a schematic cross-sectional view showing a section of a contact lens according to a third embodiment of the present invention; and

[0019] Figure 5 A flow chart illustrating the steps of a method of manufacturing a contact lens according to a fifth embodiment of the present invention is shown. DETAILED DESCRIPTION

[0020] According to a first aspect of the present invention, an ophthalmic lens (e.g., a contact lens) for preventing or slowing the development or progression of myopia is provided. The lens has a first optical axis. The first surface of the lens is shaped to form a first surface power map. The second surface of the lens is shaped to form a second surface power map. The first surface power map and the second surface power map are Figure 1 A lens power map is formed together. One of the first surface power map, the second surface power map, and the lens power map includes a basic area and a myopia control area. The basic area focuses light to a focus located on the first optical axis. The myopia control area includes a spiral shape and focuses light to a plurality of focuses offset from the first optical axis.

[0021] Conventional lenses for correcting myopia (e.g., spectacle lenses and contact lenses) reduce the convergence (in the case of contact lenses) or cause divergence (in the case of spectacle lenses) of incoming light from distant objects before it reaches the eye, so that the position of the focus is shifted onto the retina. It may be the case that the base power is a positive power (i.e., the base power causes light incident on the lens from an infinitely distant point source on the first optical axis to converge to a focus). The curvature power of the myopia control zone may be greater than the base power. It may be the case that the base power is a negative power (i.e., the base power causes light incident on the lens from an infinitely distant point source on the first optical axis to diverge). In this case, it may be the case that the curvature power of the myopia control zone is less negative than the base power. It may be the case that the base zone is configured to focus light to a focus located on the first optical axis when in use (i.e., when the lens is worn by a user). Therefore, it may be the case that the base zone is configured to focus light to a focus located on the first optical axis in cooperation with the focus provided by the optical configuration of the user's eye. Similarly, it may be the case that the myopia control zone focuses light to a plurality of focal points offset from the first optical axis when in use (i.e. when the lens is worn by a user). It may be the case that the myopia control zone is configured to focus light to a plurality of focal points offset from the first optical axis in cooperation with the focus provided by the optical configuration of the user's eye.

[0022] Ophthalmic lenses may include contact lenses. Ophthalmic lenses may include spectacle lenses. Ophthalmic lenses may include intraocular lenses. As used herein, the term contact lens refers to an ophthalmic lens that can be placed on the front surface of the eye. It should be understood that such contact lenses will provide clinically acceptable on-eye movement rather than being combined with one or both eyes of a person. The contact lens may be in the form of a corneal lens (e.g., a lens placed 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 can be used to prevent or slow the development or progression of myopia. The lens can be used to provide an extended depth of focus to a myopic eye.

[0023] Contact lenses according to embodiments of the present invention may include an optical zone. In these embodiments, the optical zone may cover an optically functional portion of the lens. It may be the case that the optical zone is configured to be positioned on the pupil of the eye when in use. For contact lenses according to the present disclosure, the optical zone includes a basic area and a myopia control area. The optical zone may be surrounded by a peripheral zone. In these embodiments, it may be the case that the peripheral zone is not part of the optical zone, but is located outside the optical zone and on the iris when the lens is worn. The peripheral zone may provide mechanical functions (e.g., increasing the size of the lens to make the lens easier to handle, providing ballasting to prevent the lens from rotating, and / or providing a shaped area that improves the comfort of the lens wearer). The peripheral zone may extend to the edge of the contact lens.

[0024] Contact lenses according to embodiments of the present disclosure may include a vertical weight to orient the lens when the lens is positioned on the wearer's eye. Embodiments of the present disclosure that incorporate vertical weight into a contact lens will rotate to a predetermined repose angle when placed on the wearer's eye under the action of the wearer's eyelid; for example, the vertical weight may be a wedge and the rotation may be caused by the action of the eyelid on the wedge. It is well known in the art to add vertical weight to a contact lens to orient the contact lens; for example, a toric contact lens is vertically weighted to orient the lens so that the orthogonal cylindrical correction provided by the lens is properly aligned for the astigmatism of the wearer's eye. It may be the case that a contact lens of the present disclosure provides a particular benefit to the wearer in a given orientation. For example, a contact lens may provide a particular benefit to the wearer when the meridian of maximum add power is in a particular orientation.

[0025] Contact lenses according to embodiments of the present invention may be generally circular in shape and have a diameter from about 4 mm to about 20 mm. The optical zone may be generally circular in shape and may 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.

[0026] The first optical axis may be along the centerline of the lens. The central region may focus light from a distant object on the first optical axis to a location on the first optical axis at a telefocus surface. As used herein, the term surface does not refer to a physical surface, but rather to a surface that can be drawn by focusing the point at which light from a distant object is 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 the curved retina. In a perfectly focused eye, the curvature of the image shell would match the curvature of the retina, and therefore, the eye does 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.

[0027] It may be the case that the base zone has a curvature centred on a centre of curvature lying on the first optical axis.It may be the case that the myopia control zone has a centre of curvature offset from the optical axis.

[0028] It may be the case that one of the first surface power map, the second surface power map, and the lens power map includes a curvature power map.

[0029] As mentioned above, the myopia control zone includes a spiral shape. It may be the case that the myopia zone forms a spiral shape. It may be the case that the myopia control zone includes more than one (e.g., two) spiral shapes. In this case, it may be the case that the two spiral shapes twist in opposite directions; that is, one spiral twists in a clockwise direction and the other twists in a counterclockwise direction. In the case where the myopia control zone includes more than one spiral shape, it may be the case that those spiral shapes are superimposed so that they combine to form another shape (e.g., different from the shapes that constitute the spiral). It can be said that these spirals rotate in opposite directions. It should be understood that the direction of the spiral twist should be evaluated from the viewpoint of the wearer of the ophthalmic lens. Therefore, it may be the case that a single surface power map of the ophthalmic lens includes two spirals that rotate in opposite directions.

[0030] It may be the case that the spiral is formed so that the curvature power map along the meridian undergoes a progressive shift radially towards or away from the optical axis as the angle of the meridian increases. Thus, a first meridian may be considered to have a curvature power map that defines the curvature power of the surface / lens along the first meridian. A second meridian that is angled adjacent to the first meridian may be considered to have a curvature power map that defines the curvature power of the surface / lens along the second meridian. It may be the case that the curvature power map along the second meridian is substantially the same as the curvature power map of the first meridian, but has undergone a radial translation in a first direction (towards or away from the optical axis). Similarly, the curvature power map along a third meridian that is adjacent to the second meridian may be substantially the same as the curvature power map of the second meridian, but has undergone a radial translation in the first direction (i.e., in the same direction as the translation between the first meridian and the second meridian). Thus, increasing the angle of the meridian being observed produces a steady progression of radial shifts of the curvature degree map.Thus, one skilled in the art will understand that in this context, "progressive shift" refers to a continuous translation in a constant direction.

[0031] It may be the case that one of the first surface power map, the second surface power map, and the lens power map may be considered to include a plurality of imaginary radial bands extending outwardly from the optical axis. In this case, it may be the case that the curvature power map of each of the plurality of imaginary radial bands is substantially the same as an adjacent radial band of the plurality of imaginary radial bands, except that it has been radially shifted toward or away from the optical axis. Thus, the spiral formed by the myopia control zone may have a pixelated appearance, wherein the spiral is simulated by distinct segments. In other embodiments, the progressive radial shifting of the power map along the meridian comprises a smooth continuous shifting. In this case, it may be the case that a smooth spiral is formed.

[0032] It may be the case that the spiral is formed such that an increase in radial distance from the optical axis imparts a progressive rotation of the optical axis about the circle at a radial distance in one of the first surface power map, the second surface power map, and the lens power map. Thus, it may be the case that a first circle of the lens may be considered to have a curvature power map defining the degree of curvature along the first circle. A second circle of the lens radially adjacent to the first circle may be considered to have a curvature power map defining the degree of curvature along the second circle. It may be the case that the curvature power map along the second circle is substantially the same as the curvature power map of the first circle, but has undergone an angular rotation about the optical axis in a first direction (i.e., clockwise or counterclockwise). Similarly, the curvature power map along a third circle radially adjacent to the second circle may be substantially the same as the curvature power map of the second circle, but has undergone an angular rotation about the optical axis in a first direction (i.e., in the same direction as the rotation between the first and second meridians). Thus, increasing radial distance from the optical axis of the observed circle produces a steady progression of the angular shift of the curvature degree map.

[0033] It may be the case that one of the first surface power map, the second surface power map, and the lens power map may be considered to include a plurality of imaginary annular rings. In this case, it may be the case that the power map of each of the plurality of imaginary annular rings is substantially the same as an adjacent annular ring of the plurality of imaginary annular rings except that it has been rotated about the optical axis. Alternatively, the progressive rotation of the circle of one of the first surface power map, the second surface power map, and the lens power map comprises a smooth continuous rotation.

[0034] It may be the case that the helix comprises more than 2 arms, preferably more than 4 arms, more preferably more than 8 arms, and even more preferably more than 16 arms. It may be the case that each arm of the helix twists at least half a rotation, preferably at least one full rotation, more preferably at least one and a half rotations, and even more preferably at least two rotations.

[0035] It may be the case that each arm of the spiral extends from the optical axis of the portion to the periphery of the power map. Contact lenses according to embodiments 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 may provide a substantially constant ratio of base power (corresponding to hyperopic focus) to myopic defocus in the presence of varying pupil dilations. These embodiments may provide a more consistent myopic defocus image under different light conditions than concentric ring lens designs and may also provide a more consistent myopic defocus image when the lens is decentered than concentric ring contact lens designs.

[0036] The myopia control area may be adjacent to the basic area. The blended area may be provided between the basic area and the myopia control area. It may be the case that the blended area does not substantially affect the optical configuration provided by the basic area or the myopia control area. Thus, it may be the case that one of the first surface power map, the second surface power map and the lens power map further includes a blended area. In this case, the blended area may separate the basic area from the myopia control area. The blended area may vary to provide a smooth transition between the basic area and the myopia control area.

[0037] As mentioned above, the base region focuses light to a focal point located on the first optical axis, while the myopia control region focuses light to a plurality of focal points offset from the first optical axis. Thus, light rays from a distant point source traveling through the base region converge toward a point on the first optical axis. Light rays from a distant point source traveling through the myopia control region converge toward one or more points at a distance from the first optical axis.

[0038] It may be that, in addition to focusing light to a plurality of focal points offset from the first optical axis, the myopia control region may also focus light to one or more points located on the first optical axis (e.g., light travels through a particular portion of the myopia control region). Thus, it may be that only a subset of the focal points formed by the myopia control region are offset from the first optical axis. It may be that the spiral formed by the myopia control region comprises a plurality of arms. In this case, it may be that one or more of the plurality of arms focuses light to one or more focal points located on the first optical axis and one or more other of the plurality of arms may focus light to one or more focal points offset from the first optical axis.

[0039] The plurality of focal points formed by the myopia control zone may include at least one focal point for each meridian of the lens / surface power map. Thus, it may be the case that each meridian of the lens / surface power map forms one of the plurality of focal points. In the case where a given meridian of the lens / surface power map comprises more than one arm of a spiral, it may be the case that the myopia control zone at that meridian forms two focal points. Thus, it may be the case that each arm of the spiral in each meridian of the lens / surface power map forms one of the plurality of focal points. Thus, it may be the case that each arm of each meridian of the lens / surface power map comprises its own local focal point, the local focus comprising one of the plurality of focal points of the myopia control zone.

[0040] It may be the case that the offset of the optical axis from the focal point of the myopia control zone is substantially constant across the lens. For example, where the centre of curvature of the myopia control zone is substantially constant across the lens, the focal point of the myopia control zone may form a ring around and centred on the optical axis.

[0041] It may be the case that the offset of the optical axis from the focus of the myopia control zone varies across the lens. In this case, the offset of the optical axis from the focus of the myopia control zone may vary depending on the radial distance from the optical axis. It may be the case that the spiral formed by the myopia control zone includes one or more arms. In this case, the offset of the focus of the myopia control zone may vary so that light incident on a radial edge (e.g., a radially outermost or innermost edge or centerline) of each of the one or more arms is directed toward the focus of the basic area. It may be the case that the offset of the focus of the myopia control zone may vary so that light incident on the centerline of each of the one or more arms is directed toward the focus of the basic area. It will be appreciated that in other embodiments, the offset of the focus may vary so that other portions of the spiral direct incident light toward the focus of the basic area. It will be appreciated by those skilled in the art that in this context, the incident light is from an infinitely distant point source positioned on the first optical axis.

[0042] It may be the case that the base power varies across the surface / lens power map. The base power may vary as a function of radial distance from the optical axis (e.g. linearly, exponentially or monotonically). For example, it may be the case that the base power decays radially outwards from the centre of the portion (e.g. linearly).

[0043] It may be that the spiral varies across the surface / lens power map. It may be that the peak power of one or more arms of the spiral varies as a function of one or both of: radial distance from the optical axis and azimuthal position about the optical axis. It may be that the peak power of at least one arm of the spiral is different from the peak power of the other arms. Thus, it may be said that each arm of the spiral has a different power. It may be that the peak power of each arm of the spiral is different from the peak power of the other arms. It may be that the twist rate of the spiral varies as a function of the radial distance from the center of the portion. The twist rate of the spiral will be understood to mean the rate at which the arms of the spiral rotate around the center of the spiral (i.e. the number of revolutions of the arms around the center of the spiral across a given radial distance). It may be that the width of one or more arms of the spiral is different from the corresponding width of the other arms of the spiral.

[0044] It may be the case that the base zone closely surrounds the optical axis such that the lens comprises a central portion into which the myopia control zone does not extend and an outer portion surrounding the central portion and comprising the myopia control zone. It may be the case that the power of the surface / lens power map is substantially constant. It may be the case that the outer portion comprises a spiral. The central portion providing the base power to the surface / lens power map may increase the amount of base power provided by the surface / lens power map and thereby increase the prominence of the resulting focused image.

[0045] The diameter of the central portion may be less than 50%, preferably less than 40%, more preferably less than 30% of the diameter of the power map. It may be the case that the central portion is smaller than the wearer's smallest pupil size. Embodiments of the present invention having a central portion that is smaller than the wearer's smallest pupil size may maintain myopia control in the presence of different light conditions.

[0046] It may be that the surface / lens power map further includes a transition portion. The transition portion may surround the central portion. The outer portion may surround the transition portion. It may be that the power of the surface / lens power map changes within the transition portion to provide a smooth transition between the central portion and the outer portion. It may be that the transition portion also includes a spiral (e.g., a spiral that continues from the spiral of the myopia control zone). In these embodiments, the magnitude of the spiral in the transition portion may decay (e.g., linearly) between the outermost radius of the transition portion and the innermost radius of the transition portion. It may be that the transition spiral decays from a magnitude equal to the radius of the spiral in the outer portion (e.g., at the outermost radius) to zero (e.g., at the innermost radius).

[0047] It may be the case that the myopia control area is provided by the first surface power map. In these embodiments, the second surface power map may include a further myopia control area. The further myopia control area may also include a spiral (e.g., forming the shape of the spiral) and focus the light to a plurality of focal points offset from the first optical axis. It may be the case that the spiral of the further myopia control area twists in the opposite direction to the spiral of the myopia control area. It should be understood by those skilled in the art that the twisting direction of the spiral should be determined from the perspective of the wearer of the lens. It may be the case that each of the first and second surface power maps includes a single spiral. Therefore, it may be the case that each of the first and second surface power maps does not include more than one spiral. Therefore, it may be the case that each of the first and second surface power maps includes a myopia control area forming a spiral shape. In this case, the spirals formed on each of the first and second surface power maps may be the same but for opposite twisting directions.

[0048] It will be appreciated by those skilled in the art that the total power map of the lens is determined by the superposition of the first surface power map and the second surface power map. In an embodiment, the spirals provided by the first and second surface power maps may twist in opposite directions. Thus, it may be said that the first and second surface power maps comprise counter-rotating spirals. It may be the case that the spiral formed on the first surface power map twists in a counter-clockwise direction and the spiral formed on the second surface power map twists in a clockwise direction. Alternatively, it may be the case that 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 counter-clockwise direction.

[0049] The superposition of two counter-rotating spirals formed by the first surface power map and the second surface power map results in a lens power map that simulates a pseudo dartboard pattern of staggered annular rings or multiple out-of-focus segments. Thus, in this case, the entire lens power map changes between a first lens power (provided by the basic area) providing hyperopic vision and a second lens power (provided by the myopia control area) providing myopic defocus. In this case, the lens power map may include a plurality of segments. The plurality of segments may provide a first degree corresponding to hyperopic focus or a second degree corresponding to myopic defocus. The segments may be arranged on the lens power map such that they are radially and / or angularly staggered between hyperopic focus and myopic defocus.

[0050] As previously discussed, a contact lens having a myopia control zone in the shape of a spiral can maintain a substantially constant ratio of hyperopic focus and myopic defocus (where the spiral covers the entire lens) or a monotonically varying ratio (where the spiral covers only a radial sub-portion of the lens) as the pupil contracts or dilates. The pseudo-dartboard pattern provided by the superposition of two counter-rotating spirals also provides this same benefit. Thus, a contact lens having a power map that simulates a pseudo-dartboard pattern can effectively provide myopia control. A contact lens having a pseudo-dartboard power map reduces the variation in the ratio of myopic defocus to hyperopic focus in the presence of variable lighting conditions. This lens power map provides a more stable ratio of lens powers (i.e., the ratio of lens powers that provide myopic defocus to lens powers that provide hyperopic vision focus) in the presence of variations in the wearer's pupil size.

[0051] Since the ophthalmic lenses are intended as myopia control lenses, the wearers of the ophthalmic lenses will typically be between the ages of about 5 and 18 and therefore, the wearer's eyes are likely to be able to focus. It should therefore be understood that although the primary lens power is selected for distance vision, the wearer can also see near distances through the primary zone due to the wearer's ability to focus.

[0052] Contact lenses according to embodiments of the present invention may include elastomeric materials, silicone elastomeric materials, hydrogel materials, or silicone hydrogel materials, or combinations thereof. As understood in the field of contact lenses, hydrogels are materials that maintain water in a state of equilibrium and do not have silicone-containing chemicals. Silicone hydrogels are hydrogels containing silicone-containing chemicals. As described in the context of the present disclosure, hydrogel materials and silicone hydrogel materials have an equilibrium water content (EWC) of at least 10% to about 90% (wt / wt). In some embodiments, the hydrogel material or silicone hydrogel material has an EWC of from about 30% to about 70% (wt / wt). In contrast, as described in the context of the present disclosure, silicone elastomeric materials have a water content of from about 0% to less than 10% (wt / wt). Typically, silicone elastomeric materials used with the methods or apparatus of the present invention have a water content of from 0.1% to 3% (wt / wt). Examples of suitable lens formulations include those with the following United States Adopted Drug Names (USAN): methafilcon A, ocufdcon A, ocufdcon B, ocufilcon C, ocufilcon D, omafilcon A, omafilcon B, comfdcon A, enfilcon A, stenfdcon A, fanfdcon A, etafdcon A, senofdconA, senofilcon B, senofilcon C, narafilcon A, narafilcon B, balafilcon A, samfdconA, lotrafdcon A, lotrafilcon B, somofdcon A, riofdcon A, delefilcon A, verofilconA, kalifilcon A, and the like.

[0053] Alternatively, the lens may include, consist essentially of, or consist of a silicone elastomeric material. For example, the lens may include, 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 (e.g., using method DIN 53505). Other silicone elastomeric materials may be obtained from, for example, NuSil Technology or Dow Chemical.

[0054] According to a second aspect of the present invention, a method for manufacturing an ophthalmic lens is also provided. The method includes operating a lathe to shape a first surface of at least one of the following: a lens, a mold for a lens, or an insert for manufacturing a mold for a lens. The method further includes operating a lathe to shape a second surface of the lens, mold, or insert to form a second surface power map. The combination of the first surface power map and the second surface power map forms a lens power map having a first optical axis. One of the first surface power map, the second surface power map, and the lens power map includes a basic area and a myopia control area. The basic area focuses light to a focus located on the first optical axis. The myopia control area includes a spiral shape and focuses light to a plurality of focuses offset from the first optical axis.

[0055] The lens may include any of the features set forth above.

[0056] 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 mold part and the male mold part with a bulk lens material. The method may further include curing the bulk lens material to form a lens.

[0057] The lens may be formed using a turning process. The lens may be formed by a molding process, a spin casting process, or a turning process, or a combination thereof. As understood by those skilled in the art, molding refers to molding 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.

[0058] The method of manufacturing a lens may include designing a 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.

[0059] The method may include modeling a first lens (e.g., a contact lens). The first lens may have a basic area, the basic area having a basic power, focusing light to a focal point located on a first optical axis. The first lens may include a myopia control area, the myopia control area forming a spiral shape and focusing light to a focal point located on the first optical axis. The myopia control area may provide an additional power greater than the basic power (e.g., a curvature additional power). The method may include modeling a second lens (e.g., a contact lens). The second lens may have the same basic area as the first lens. The basic area of ​​the second lens may have the same basic power as the first lens, and may focus light to a focal point located on the first optical axis. The second lens may have a myopia control area forming a spiral shape. The myopia control area may provide an additional power greater than the basic power (e.g., a curvature additional power). The clear power of the second lens will be the sum of the basic power of the second lens and the additional power. The clear power of the second lens may be greater than the clear power of the first lens. The method of designing a lens may include, within the model, tilting the myopia control area of ​​the second lens while keeping the inner edge of the myopia control area fixed. The method may include translating at least a portion of the basic area so that the outer edge of the myopia control area matches the corresponding edge of the basic area of ​​the first lens. The method may include, within the model, tilting each arm of the spiral formed by the myopia control area while keeping the inner edge of the arm of the spiral fixed. The method may include translating at least a portion of the basic area so that the outer edge of the arm of the spiral matches the corresponding edge of the basic area of ​​the first lens. The method may include providing a blending area between the basic area and the myopia control area. The blending area may provide a smooth transition between the basic area and the myopia control area. The method may include performing a tilt (and, where applicable, a translation) on each meridian of the lens separately. Tilting the myopia control area of ​​the second lens may divide the focus into a plurality of focal points and move those focal points away from the first optical axis. Tilting the annular area of ​​the second lens will produce a third modeled lens (e.g., a third contact lens), i.e., a tilted second lens. The third lens or the tilted second lens will have a myopia control area that produces the same clarity as the untilted second lens but has a plurality of off-axis focal points.

[0060] The method of manufacturing a lens may include manufacturing a lens based on a modeled third lens (i.e., a tilted 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, this 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.

[0061] It may be that the method further comprises the step of designing the lens. Designing may comprise defining, for a first meridian of one of the first surface, the second surface, and the lens, a curvature power distribution along the meridian. Designing may further comprise defining, for a second meridian of one of the first surface, the second surface, and the lens adjacent to the first meridian, a second curvature power distribution along the meridian. It may be that the second curvature power distribution is substantially identical to an adjacent radial zone of the plurality of radial zones except having been radially shifted toward or away from the optical axis.

[0062] According to a third aspect of the present invention, there is also provided a method for preventing or slowing the development or progression of myopia in a person. The method comprises providing the person with a lens (eg, a contact lens) according to the first aspect.

[0063] Figure 1 A schematic plan view of a contact lens 100 according to an example embodiment of the present invention is shown. The contact lens 100 includes an optical zone 101 that roughly covers the pupil and a peripheral zone 103 located above the iris. The peripheral zone 103 provides mechanical functions, including increasing the size of the lens so that the lens 100 is easier to handle, providing a sag to prevent rotation of the lens 100, and providing a shaped area that improves the comfort of the wearer of the lens 100. The optical zone 101 provides the optical functionality of the lens 100. The optical zone 101 includes a basic zone 105 and a myopia control zone 107. The myopia control zone 107 forms a spiral shape.

[0064] exist Figure 1 In the specific embodiment illustrated in FIG. 1 , the spiral formed by the myopia control region 107 includes three arms. However, it should be understood that in other embodiments, the spiral may have more or fewer arms. Similarly, although in FIG. Figure 1 In the exemplary embodiment illustrated in , the helix twists in a counterclockwise direction, but in other embodiments, the helix may twist in a clockwise direction.

[0065] exist Figure 1 In the illustrated embodiment of the present invention, the lens 100 includes a central portion into which the myopia control zone 107 does not extend. The lens further includes an outer portion that includes the myopia control zone 107. The central portion has a substantially constant lens power that is equal to the base power (e.g., within the base zone). In other embodiments, the lens does not include a central portion or an outer portion; instead, the spiral formed by the myopia control zone extends from the periphery of the optical zone 101 to the optical axis of the lens 100.

[0066] Figure 2A schematic cross-sectional view of a section through a contact lens 200 according to a first embodiment of the present invention is shown. The contact lens 200 has an optical axis 201. The contact lens 200 has a first surface power map including a base area 205 that focuses light to a focal point 209 located on the optical axis 201. The first surface power map further includes a myopia control area 207 that forms a spiral shape. In this example, the second surface power map of the contact lens 200 does not provide additional focusing. Therefore, the lens power map of the contact lens 200 is the same as the first surface power map. It should be understood that due to Figure 2 A cross-sectional view of the contact lens 200 is shown so only a section through the arms of the spiral is visible. The myopia control zone 207 focuses light to a plurality of focal points 211 that are offset from the optical axis 201. In this particular embodiment, the offset of the focal points 211 from the optical axis 201 is substantially constant across the lens 200. Thus, the focal points 211 form a ring around and centered on the optical axis 201. It will be appreciated that in embodiments where the myopia control zone 207 forms a spiral that does not intersect one or more meridians of the lens, the focal points 211 will form an interrupted ring, where the interrupted locations in the ring correspond to those meridians that do not intersect the spiral.

[0067] Figure 3 A schematic cross-sectional view of a section through a contact lens 300 according to a second embodiment of the present invention is shown. The contact lens 300 has an optical axis 301. The contact lens 300 has a first surface power map including a base area 305 that focuses light to a focal point 309 located on the optical axis 301. The first surface power map further includes a myopia control area 307 that forms a spiral shape. Again, in this example, the second surface power map of the contact lens 300 does not provide additional focusing, and therefore the lens power map of the contact lens 300 is the same as the first surface power map. It should be understood that due to Figure 3 A cross-sectional view of the contact lens 300 is shown so that only a section through the arms of the spiral is visible. The myopia control region 307 focuses light to a plurality of focal points 311 that are offset from the optical axis 301. In this particular embodiment, the curvature of the myopia control region 307 is such that the offset of the focal points 311 of the myopia control region 307 from the optical axis 301 varies according to the radial distance from the optical axis 301. In this example, the offset of the focal points 311 from the optical axis 301 varies so that light incident on the radially outermost edge of each of the one or more arms is directed toward the focal point 309 of the base region 305. Thus, the focal points 311 form a spiral around the optical axis 301. Those skilled in the art will appreciate that in this context, the incident light is from an infinitely distant point source positioned on the first optical axis.

[0068] Figure 4A schematic cross-sectional view of a section through a contact lens 400 according to a third embodiment of the present invention is shown. The contact lens 400 is identical to the contact lens 300 of the third embodiment (with a myopia control zone 407), except that the offset of the focus 411 from the optical axis 401 is changed so that light incident on the centerline of each of the one or more arms is directed toward the focus 409 of the base zone 405. Those skilled in the art will appreciate that the centerline of the arms of the spiral extends along the vertical midpoint of the arms.

[0069] In addition to the following features, a fourth exemplary embodiment of the present invention includes a contact lens as described with respect to the first embodiment. Unlike the first embodiment, the second surface power map of the contact lens of the third embodiment includes a further myopia control area that forms a spiral shape and focuses light to further multiple focal points offset from the first optical axis. The spiral formed by the further myopia control area is substantially the same as the spiral formed by the myopia control area on the first surface power map except that it twists in the opposite direction. Therefore, it can be said that the contact lens of the third embodiment has two myopia control areas that form counter-rotating spirals. Therefore, the lens power map of the contact lens of the third embodiment forms a pseudo-dartboard pattern of staggered annular rings of multiple segments of hyperopic focus and myopic defocus. The entire lens power map changes between a first lens power (provided by the basic area) that provides hyperopic vision and a second lens power (provided by the myopia control area) that provides myopic defocus.

[0070] Figure 5 A method 500 of manufacturing a lens (eg, a contact lens) according to a fifth embodiment of the present invention is shown.

[0071] An optional first step of the method, represented by item 510, includes designing a lens. It may be that the lens includes a first surface power map and a second surface power map. In this case, it may be that the combination of the first surface power map and the second surface power map includes the lens power map. Designing the lens may include a first sub-step, represented by item 511, defining a curvature power distribution along a first meridian of one of the first surface power map, the second surface power map, and the lens power map. Designing the lens may include a second sub-step, represented by item 513, defining a second curvature power distribution along a second meridian of one of the first surface, the second surface, and the lens adjacent to the first meridian. It may be that the second curvature power distribution is substantially identical to adjacent radial zones of the plurality of radial zones except that it has been radially shifted toward or away from the optical axis. Designing the lens may include a third sub-step represented by item 515, namely defining a further curvature power distribution for a further meridian such that the first, second and further curvature power maps are substantially identical except that they have been radially shifted towards or away from the optical axis. It may be the case that the radial shifting of the curvature power maps is such that the curvature power maps are progressively shifted in the same direction as the angle of the meridian being viewed increases.

[0072] A second step of method 500 , represented by item 530 , includes operating a lathe to shape a first surface of at least one of: a lens, a mold for a lens, or an insert for a mold for manufacturing a lens.

[0073] The third step of method 500, represented by item 550, includes operating a lathe to shape a second surface of the lens, mold, or insert to form a second surface power map.

[0074] The first surface and the second surface are shaped so that one of the first surface power map, the second surface power map, and the lens power map includes a basic area and a myopia control area. The basic area has a basic power and focuses light to a focus located on the first optical axis. The myopia control area forms a spiral shape and focuses light to a plurality of focuses offset from the first optical axis.

[0075] It will be appreciated by those skilled in the art that the method can include forming the first and second surfaces such that the lens includes any of the features described above with respect to the contact lenses of the present invention.

[0076] Although the present invention has been described and illustrated with reference to specific embodiments, it will be appreciated by those skilled in the art that the present invention lends itself to many different variations not explicitly described herein. By way of example only, specific possible variations will now be described.

[0077] In the described embodiments, the surface power map of the lens includes a central portion having a substantially constant power, an outer portion incorporating a myopia control zone, and a transition zone that provides a smooth transition between the central portion and the outer portion. However, some alternative embodiments do not incorporate a transition portion. Further alternative embodiments do not incorporate distinct central and outer portions. Instead, in these embodiments, the spiral formed by the myopia control zone extends outward from the center of the power map all the way to the radial periphery of the power map.

[0078] In some embodiments of the present invention, the spiral formed by the myopia control zone changes its rotational direction at a predetermined radial distance from the optical axis of the lens. For example, the spiral may rotate in a clockwise direction between the optical axis of the lens and the predetermined radial distance, and rotate in a counterclockwise direction beyond the predetermined radial distance. The lens may incorporate more than one change in the rotational direction of the spiral. Thus, the spiral may, for example, change from clockwise rotation to counterclockwise rotation before reverting to clockwise rotation again. It should be understood by those skilled in the art that the lens may incorporate any number of changes in the rotational direction of the spiral. It should also be understood that each of those changes in direction may occur at any selected radial distance from the optical axis of the lens. Therefore, a surface or lens power map according to an embodiment of the present invention may include annular rings interlaced between clockwise rotating spirals and counterclockwise rotating spirals. In these embodiments, it may be the case that each counter-rotating spiral changes its rotational direction at the same radial distance from the optical axis of the lens.

[0079] In some embodiments, between portions of the power map having different directions of rotation, there may be regions where the power map does not vary as a spiral. For example, the region may have a substantially constant power. For example, from the center of the lens to a first radial distance, the myopia control region may form a clockwise rotating spiral before forming a counterclockwise rotating spiral, followed by a region of substantially constant power. Thus, the power map may appear to include, for example, a plurality of annular rings that are interlaced between a spiral and a substantially constant power, wherein the rings that make up the spiral are also interlaced between clockwise and counterclockwise rotation.

[0080] Similarly, in some embodiments, the spiral formed by the myopia control zones may be interrupted by one or more areas (e.g., rings) where the power map does not change as a spiral. These areas may have a substantially constant power (e.g., a base power). Thus, for example, the power map may include annular rings that are interleaved between the spiral formed by the myopia control zones and the base power. In these embodiments, the spiral may change its rotational direction between each interruption, or it may continue its previous rotational direction. Thus, the spiral may maintain a constant rotational direction across the lens, but may be interrupted by areas of substantially constant lens power.

[0081] While the lenses described above have base regions with substantially constant base powers and myopia control regions that form a regular spiral shape, it will be appreciated by those skilled in the art that other embodiments of the invention do not necessarily require this. For example, in other embodiments, the base power varies across the surface / lens power map. The base power may vary as a function of radial distance from the optical axis (e.g., linearly, exponentially, or monotonically). For example, it may be the case that the base power decays radially outward from the center of the portion (e.g., linearly).

[0082] It may be that the spiral formed by the myopia control zone varies across the surface / lens power map. It may be that the peak power of one or more arms of the spiral formed by the myopia control zone varies according to one or more of the following: radial distance from the optical axis and azimuthal position about the optical axis. It may be that the peak power of at least one arm of the spiral is different from the peak power of the other arms. Therefore, it can be said that each arm of the spiral has a different power. It may be that the peak power of each arm of the spiral is different from the peak power of the other arms. It may be that the twist rate of the spiral varies according to the radial distance from the center of the portion. The twist rate of the spiral will be understood to mean the rate at which the arms of the spiral rotate around the center of the spiral (i.e. the number of revolutions of the arms around the center of the spiral across a given radial distance). It may be that the width of one or more arms of the spiral is different from the corresponding width of the other arms of the spiral.

[0083] Although the embodiments of the present invention have been described above with respect to a method of manufacturing a lens, a mold of a lens, or an insert for a mold of a lens using a lathe, it should be understood that other manufacturing methods are also possible. For example, the mold or insert may also be manufactured using additive manufacturing technology (e.g., by 3D printing).

[0084] An embodiment of the present invention also provides a lens (e.g., a contact lens) for preventing or slowing the development or progression of myopia, wherein:

[0085] The lens has a first optical axis;

[0086] The first surface of the lens is shaped to form a first surface power map;

[0087] The second surface of the lens is shaped to form a second surface power map;

[0088] The first surface degree map and the second surface degree map Figure 1 to form a lens power map; and

[0089] One of the first surface power map, the second surface power map, and the lens power map comprises:

[0090] a base region having a curvature providing a base power and centered about a center of curvature located on the first optical axis; and

[0091] A myopia control zone comprises a spiral shape and has a center of curvature offset from the optical axis.

[0092] Although in the foregoing description, mention has known obvious or foreseeable equivalent whole or element, but these equivalents are incorporated herein as if set forth individually. The claims should be referenced to determine the true scope of the present invention that should be interpreted as covering any of these equivalents. The reader should also understand that the whole or feature of the present invention described as preferably, advantageously, conveniently or the like is optional, and does not limit the scope of the independent claims. In addition, it should be understood that these optional wholes or features, although they may be beneficial in some embodiments of the present invention, may not be desired and therefore may not exist in other embodiments.

Claims

1. An ophthalmic lens for preventing or slowing the development or progression of myopia, wherein: The lens has a first optical axis; The first surface of the lens is shaped to form a first surface power map; The second surface of the lens is shaped to form a second surface power map; The first surface power map and the second surface power map together form a lens power map; and One of the first surface power map, the second surface power map, and the lens power map comprises: a base area having a base power, the base area focusing light to a focus located on the first optical axis; and a myopia control zone comprising a spiral shape and focusing light into a plurality of focal points offset from the first optical axis, wherein the plurality of focal points: forming a ring around and centered on the first optical axis, or When the spiral shape includes a spiral that does not intersect one or more meridians of the lens, an interrupted ring is formed, wherein the interrupted positions in the interrupted ring correspond to the one or more meridians that do not intersect the spiral.

2. The ophthalmic lens of claim 1, wherein: The one of the first surface power map, the second surface power map, and the lens power map comprises a curvature power map; and The spiral is formed so that the degree map along a meridian undergoes a progressive shift radially toward or away from the optical axis as the angle of the meridian increases.

3. The ophthalmic lens of claim 2, wherein: The one of the first surface power map, the second surface power map, and the lens power map comprises a plurality of imaginary radial zones extending outward from the optical axis; and The degree of curvature map of each of the plurality of imaginary radial zones is substantially identical to the adjacent radial zone of the plurality of imaginary radial zones, except having been shifted radially toward or away from the optical axis.

4. The ophthalmic lens of claim 2, wherein the radial shift of the power map along a meridian of said one of the first surface power map, the second surface power map, and the lens power map comprises a smooth continuous shift.

5. The ophthalmic lens of claim 1, wherein the offset of the optical axis from the focal point of the myopia control zone is substantially constant across the lens.

6. The ophthalmic lens of claim 1, wherein said one of the first surface power map, the second surface power map, and the lens power map further comprising a blended region; The blending region separates the base region from the myopia control region; and The blending region varies to provide a smooth transition between the base region and the myopia control region.

7. The ophthalmic lens of claim 1, wherein the primary region closely surrounds the optical axis such that the lens comprises: a central portion into which the myopia control area does not extend; and An outer portion surrounds the central portion and includes the myopia control zone.

8. The ophthalmic lens of claim 7, wherein: The lens includes a transition portion; The transition portion surrounds the central portion and the outer portion surrounds the transition portion; and The transition portion changes to provide a smooth transition between the central portion and the outer portion.

9. The ophthalmic lens of claim 1, wherein: The myopia control area is provided by the first surface power map; the second surface power map comprising a further myopia control region comprising a spiral shape and focusing light to a further plurality of focal points offset from the first optical axis; The spiral formed by the further myopia control zone twists in an opposite direction to the spiral formed by the myopia control zone.

10. The ophthalmic lens of claim 1 wherein the myopia control zone provides an additional power of curvature greater than the base power.

11. A method of manufacturing an ophthalmic lens, the method comprising: operating a lathe to shape a first surface of at least one of: a lens, a mold for a lens, or an insert for a mold for making a lens; operating a lathe to shape a second surface of the lens, mold, or insert to form a second surface power map; in: The combination of the first surface power map and the second surface power map forms a lens power map having a first optical axis; and One of the first surface power map, the second surface power map, and the lens power map comprises: a primary area having a primary power, the primary area focusing light to a focal point located on the first optical axis; and a myopia control zone comprising a spiral shape and focusing light into a plurality of focal points offset from the first optical axis, wherein the plurality of focal points: forming a ring around and centered on the first optical axis, or When the spiral shape includes a spiral that does not intersect one or more meridians of the lens, an interrupted ring is formed, wherein the interrupted positions in the interrupted ring correspond to the one or more meridians that do not intersect the spiral.

12. The method according to claim 11, further comprising: The ophthalmic lens is designed by: defining, for a first meridian of said one of the first surface, the second surface, and the lens, a curvature power distribution along the meridian; defining a second curvature degree profile along a second meridian adjacent to the first meridian for said one of the first surface, the second surface, and the lens; Wherein the second degree of curvature distribution is substantially the same as the adjacent radial band of the plurality of radial bands except having been shifted radially toward or away from the optical axis.

Images