Contact lenses and related methods

Abstract

A contact lens (301) and a method for manufacturing such a lens (301) are described. The lens (301) includes an optic zone (302). The optic zone (302) includes a central region (305) having a first optical axis, a center of curvature that lies on the first optical axis, and a diameter that is less than 2.0 mm. The optic zone (302) includes an annular region (303). The annular region (303) includes a plurality of concentric treatment regions (303 a, 303 b), each having a radial sagittal power profile that increases with increasing radial distance from the optical axis.

Description

[Technical Field]

[0001] The present invention relates to contact lenses. The present invention particularly (but not exclusively) relates to contact lenses for slowing the progression of myopia. The present invention particularly (but not exclusively) relates to contact lenses for use by presbyopes. The present invention also relates to methods of making such lenses. [Background technology]

[0002] Many people, both children and adults, need contact lenses to correct myopia (nearsightedness), and many adults may need lenses to correct presbyopia (the inability to focus on nearby objects due to age-related loss of accommodation).

[0003] An uncorrected myopic eye focuses incident light from distant objects at a location in front of the retina. As a result, the light converges toward the plane in front of the retina and diverges toward the retina, reaching the retina out of focus. Conventional lenses for correcting myopia (e.g., eyeglass lenses and contact lenses) reduce the convergence (in the case of contact lenses) or cause the incident light to diverge (in the case of eyeglasses) before it reaches the eye, thereby shifting the focus point onto the retina.

[0004] The internal lens of a presbyopic eye does not change shape to add the required refractive power needed to focus on near objects. Traditional lenses for correcting presbyopia (e.g., spectacle lenses or contact lenses) contain additional positive refractive power that is lacking in bifocal or progressive lenses, which include an area optimized for near vision and an area optimized for distance vision. Presbyopia can also be treated using bifocal or multifocal lenses, or monovision lenses (where each eye is provided with a different prescription, such as one eye provided with a lens for distance vision and the other provided with a lens for near vision).

[0005] Decades ago, it was proposed that the progression of myopia in children and adolescents could be slowed or prevented by undercorrection, i.e., by bringing the focal point closer to the retina but not completely onto it. However, this approach inevitably resulted in decreased distance vision compared to that achieved with lenses that fully correct myopia. Furthermore, the effectiveness of undercorrection in controlling myopia progression is now considered questionable. A more recent approach to correcting myopia is to provide lenses that have both one or more regions that provide full correction of distance vision and one or more regions that undercorrect, i.e., intentionally induce myopic defocus. It has been suggested that this approach can prevent or slow the onset or progression of myopia in children and adolescents while providing good distance vision. In lenses with regions that provide defocus, the region that provides full correction of distance vision is typically referred to as the base power region, and the region that provides undercorrection or intentionally induces myopic defocus is typically referred to as the myopic defocus region or add power region (where the power is more positive or less negative than the power (diopter) of the distance region).

[0006] The surface of the add-power region (typically the anterior surface) has a smaller radius of curvature than the distance-power region, thus providing a more positive or less negative optical power (diopter) to the eye. The add-power region is designed to focus incoming parallel light (i.e., light from farther away) into the eye in front of the retina (i.e., closer to the lens). The distance-power region is designed to focus light to form an image on the retina (i.e., closer to the lens).

[0007] A known type of contact lens that reduces the progression of myopia is the bifocal contact lens, available under the name MISIGHT (CooperVision, Inc.). Unlike bifocal and multifocal contact lenses designed to improve vision in presbyopic individuals, bifocal lenses are constructed with predetermined optical dimensions that provide the use of distance correction (i.e., base power) to view both distant and near objects. The treatment zone of the bifocal lens, which has an add power, provides myopic defocused images at both distant and near viewing distances.

[0008] While these lenses have been found to be beneficial in preventing or slowing the onset or progression of myopia, the annular add-power region can cause undesirable visual side effects. Light focused by the annular add-power region in front of the retina diverges from its focal point, forming a defocused ring on the retina. Thus, under some circumstances, wearers of these lenses may see a ring or "halo" around the image formed on the retina, particularly for small, bright objects such as street lamps or car headlights. Also, rather than using the eye's natural accommodation (i.e., the eye's natural ability to change focal length) to focus on nearby objects, the wearer could theoretically use the additional focal point in front of the retina resulting from the annular add-power region to focus on nearby objects. This, in turn, could result in the wearer unconsciously (without realizing) using the lenses in the same manner as presbyopia-correcting lenses are used, which is undesirable in young subjects and could impair their ability to slow the progression of myopia by filtering out light that is not focused by myopia.

[0009] Further lenses have been developed that can be used to treat myopia and are designed to eliminate the halos observed around focal distance images. In these lenses, an annular region is configured to prevent an on-axis image from being formed in front of the retina, thereby preventing such an image from being used to avoid the eye's need to accommodate to near objects. Rather, the annular region prevents a distant point source from being imaged into a ring-shaped focal line at the near add-power focal plane, thereby preventing a useful image from being produced at that plane. A second advantage of this type of lens is that the light rays that form the ring-shaped image (focal line) can overlap when they reach the retina, resulting in a small spot size of light on the retina without the surrounding "halo" effect.

[0010] It has been recognized that for the treatment of myopia, it may be beneficial to provide a lens that introduces additional myopic defocus. For the treatment of presbyopia, it may be beneficial to provide a lens that extends the depth of focus. Summary of the Invention

[0011] According to a first aspect, the present disclosure provides a contact lens including an optic zone. The optic zone includes a central region having a first optical axis, a center of curvature lying on the first optical axis, and a diameter less than 2.0 mm. The optic zone includes an annular region including a plurality of concentric treatment zones. Each treatment zone has a radial sagittal power profile that increases with increasing distance from the optical axis.

[0012] According to a second aspect, the present disclosure provides a method of manufacturing a lens. The method may include forming a contact lens. The contact lens comprises an optic zone including a central region, the central region having a first optical axis, a center of curvature that lies on the first optical axis, and a diameter that is less than 2.0 mm. The optic zone includes an annular region having a plurality of treatment zones, each treatment zone having a radial sagittal power profile that increases with increasing distance from the optical axis.

[0013] Of course, it will be understood that features described in connection with one aspect of the present disclosure may be incorporated in other aspects of the present disclosure, for example, a method of the present disclosure may incorporate features described with reference to an apparatus of the present disclosure, and vice versa.

[0014] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying schematic drawings. [Brief explanation of the drawings]

[0015] [Figure 1A] FIG. 1A is a plan view of a prior art contact lens used to prevent myopia.

[0016] [Figure 1B] FIG. 1B is a side view of the contact lens of FIG. 1A.

[0017] [Figure 2A] FIG. 2A is a ray diagram of the lens of FIG. 1A.

[0018] [Figure 2B] FIG. 2B shows a light pattern at the near focal plane of the lens of FIG. 1A formed from a distant point source.

[0019] [Figure 2C] FIG. 2C shows a light pattern at the far focal plane of the lens of FIG. 1A formed from a distant point source.

[0020] [Figure 3A] FIG. 3A is a plan view of another contact lens having non-coaxial optics.

[0021] [Figure 3B] FIG. 3B is a side view of the contact lens of FIG. 3A.

[0022] [Figure 4A] FIG. 4A is a ray diagram of the lens of FIGS. 3A and 3B.

[0023] [Figure 4B] FIG. 4B shows the light pattern at the near focal plane of the lens of FIGS. 3A and 3B formed from a distant point source.

[0024] [Figure 4C] FIG. 4C shows the light pattern at the far focal plane of the lens of FIGS. 3A and 3B formed from a distant point source.

[0025] [Figure 4D] Figure 4D is a partial ray diagram of the lens of Figures 3A and 3B, along with circles showing the radii of curvature of the central distance zone (solid line) and the annular additional zone (dashed line) of the contact lens.

[0026] [Figure 5A] FIG. 5A is a plot (graph) showing the change in sagittal power of the lens shown in FIGS. 1A and 1B and the lens shown in FIGS. 3A and 3B.

[0027] [Figure 5B] FIG. 5B is a plot (graph) showing the change in curvature power of the lens shown in FIGS. 1A and 1B and the lens shown in FIGS. 3A and 3B.

[0028] [Figure 6A] FIG. 6A is a plan view of a lens according to one embodiment of the present disclosure.

[0029] [Figure 6B] FIG. 6B is a side view of the contact lens of FIG. 6A.

[0030] [Figure 7] FIG. 7 is a plot (graph) showing the change in sagittal and curvature power of the lens shown in FIGS. 6A and 6B.

[0031] [Figure 8]FIG. 8 is a ray diagram for the lens of FIGS. 6A and 6B.

[0032] [Figure 9A] FIG. 9A is a plan view of a lens according to one embodiment of the present disclosure.

[0033] [Figure 9B] FIG. 9B is a side view of the contact lens of FIG. 9A.

[0034] [Figure 10] FIG. 10 is a plot (graph) showing the variation of sagittal and curvature powers of the lenses shown in FIGS. 9A and 9B.

[0035] [Figure 11] FIG. 11 is a ray diagram of the lens of FIGS. 9A and 9B.

[0036] [Figure 12A] FIG. 12A is a plan view of a lens according to one embodiment of the present disclosure.

[0037] [Figure 12B] FIG. 12B is a side view of the contact lens of FIG. 12A.

[0038] [Figure 13] FIG. 13 is a plot (graph) showing the change in sagittal and curvature power of the lens shown in FIGS. 12A and 12B.

[0039] [Figure 14] FIG. 14 is a ray diagram of the lens of FIGS. 12A and 12B.

[0040] [Figure 15] FIG. 15 is a flowchart illustrating a method of manufacturing a lens according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0041] According to a first aspect, the present disclosure provides a contact lens comprising an optic zone including a central region having a first optical axis, a center of curvature lying on the first optical axis, and a diameter less than 2.0 mm. The optic zone includes an annular region including a plurality of concentric treatment zones. Each treatment zone has a radial sagittal power profile that increases with increasing radial distance from the optical axis.

[0042] As used herein, the term contact lens refers to an ophthalmic lens that can be placed on the front of the eye. It will be understood that such contact lenses provide clinically acceptable on-eye movement and do not bond to the human eye. The contact lens can be in the form of a corneal lens (e.g., a lens that rests on the cornea of ​​the eye). The contact lens can be a soft contact lens, such as a hydrogel contact lens or a silicone hydrogel contact lens. The lens can be a lens used to prevent or slow the onset or progression of myopia. The lens can also be a lens used to provide an extended depth of focus for presbyopic eyes.

[0043] Contact lenses according to the present disclosure include an optic zone. The optic zone encompasses portions of the lens that have an optical function. The optic zone is configured to be positioned over the pupil of the eye during use. In contact lenses according to the present disclosure, the optic zone includes a small central region and an annular region surrounding the central region. The optic zone may be surrounded by a peripheral zone. The peripheral zone is not part of the optic zone, but is located outside the optic zone and above the iris when the lens is worn, and serves a mechanical function, such as increasing the size of the lens to make it easier to handle, providing ballast to prevent lens rotation, and / or providing a geometric region that improves comfort for the lens wearer. The peripheral zone may extend to the edge of the contact lens.

[0044] A contact lens according to an embodiment of the present disclosure may include a ballast for orienting the lens when positioned on a wearer's eye. An embodiment of the present disclosure incorporating a ballast into a contact lens rotates to a predetermined angle of repose when placed on the wearer's eye by the action of the wearer's eyelid. For example, the ballast may be a wedge, and rotation may occur through the action of the eyelid on the wedge. Ballasting contact lenses to orient them is well known in the art. For example, toric contact lenses are ballasted to orient the lens so that the orthogonal cylindrical correction provided by the lens is precisely aligned with the astigmatism of the wearer's eye.

[0045] The contact lens may be substantially circular in shape and have a diameter of about 4 mm to about 20 mm. The optic zone may be substantially circular in shape and have a diameter of about 2 mm to about 10 mm. In some embodiments, the contact lens has a diameter of 13 mm to 15 mm, and the optic zone has a diameter of 7 mm to 9 mm.

[0046] The first optical axis may be along the centerline of the lens. The first optical axis is defined relative to a distant point light source. Light from a distant point light source on the optical axis of the lens (hereinafter referred to as an on-axis distant point light source) is focused onto the optical axis of the lens. The central region may have a substantially circular shape. The central region may have a substantially oval or elliptical shape. The central region has a small diameter of less than 2.0 mm. The central region may have a diameter of less than 1 mm, less than 0.5 mm, or less than 0.25 mm. If the central region is substantially oval or elliptical, the maximum diameter may be less than 2.0 mm, less than 1.0 mm, less than 0.5 mm, or less than 0.25 mm.

[0047] The annular region may extend radially outward from the periphery of the central region. The periphery of the central region may define a boundary between the central region and the annular region, and thus the annular region may be adjacent to the central region. The annular region may be a substantially annular region surrounding the optical zone. It may have a substantially circular or substantially elliptical shape. It may completely surround the optical zone. It may partially surround the optical zone.

[0048] The annular region includes multiple concentric (circular) treatment regions. The annular region may include 2 to 10 concentric treatment regions, preferably 4 to 8 concentric treatment regions. Each treatment region may have a radial width of approximately 0.1 to 2.5 mm, preferably approximately 0.2 to 1.2 mm, and more preferably approximately 0.3 to 1.0 mm. Each treatment region may have the same radial width. Alternatively, multiple treatment regions may have different radial widths.

[0049] Each treatment area may directly abut an adjacent treatment area, i.e., the outer edge of a first treatment area may define a boundary between the first and second treatment areas, and thus the second treatment area may be adjacent to the first treatment area.

[0050] In ophthalmology, the term "sagittal" is used in two different ways: to describe oblique astigmatism and to describe optical surfaces.

[0051] In general optical systems, the term "sagittal" is used to describe oblique astigmatism. Oblique astigmatism occurs when light rays from off-axis locations pass through a lens at an oblique angle. Astigmatism can be attributed primarily to cosine compression, which occurs in the meridian along which the light rays originate. For example, if a light ray originates from the horizontal peripheral field, the surface (and therefore the radius of curvature) appears cosine compressed horizontally. This results in increased power (and therefore increased astigmatism) in that meridian. The power in that meridian is called "tangential" power, and the power in the vertical meridian is called "sagittal" power. This astigmatism causes object points to be imaged into two spatially separated, orthogonal focal lines: a sagittal focal line and a tangential focal line.

[0052] The second use of the term "sagittal" comes from describing optical surfaces. For example, in ophthalmology, it is central to clinical measurements of the anterior surface of the eye (i.e., corneal topography). Terms including "sagittal power," "tilt power," and "axial power" are synonyms used interchangeably to describe the optical power of a lens surface, obtained from the location where a ray of light passing through that surface intersects the optical axis. In the paraxial approximation, sagittal power is equal to the "power" of the lens.

[0053] An optical surface is typically defined by its radius because this radius is directly related to the optical power (power = refractive index difference / radius). In most optical systems, in the paraxial approximation, the surface is considered to have a single radius (i.e., it is assumed to be part of a single sphere). However, in the human eye, the anterior corneal surface is far from spherical, and a single radius is not sufficient to define such a surface because the local radius varies along the lens surface. Similarly, aspheric ophthalmic lenses (e.g., contact lenses) also have local radii that vary along the lens surface.

[0054] Due to the aspheric properties of ocular and contact lens optics, two definitions of radius are employed. The sagittal radius of curvature of a local surface is the distance to the point where the normal to the surface intersects the optical axis. Using the small angle approximation, this is equal to the distance from the pupil center to that point, so that distance from the pupil center is typically used.

[0055] Another radius to consider for a complete picture of a surface's optical power is the local radius of curvature, which is based on the local curvature of the surface. (The sagittal radius is sometimes called the axial radius, and the local radius is sometimes called the instantaneous radius.)

[0056] Using the paraxial optics equation (power = refractive index difference / radius), the sagittal radius is used to calculate sagittal power, and the local radius is used to calculate curvature power (also known as local power or instantaneous power, the latter implying a relationship with the local radius of curvature). Sagittal power is also called tilt-based power because it is determined by the tilt of the optical surface.

[0057] As explained further below, when describing an optical wavefront, sagittal power is defined as the slope of the wavefront divided by the radial distance (r) from the optical axis of the lens (typically the center of the lens). That is, it is related to the first derivative of the wavefront. (Local) curvature power is defined by the second derivative of that wavefront.

[0058] For low-aberration optical systems (e.g., single-vision lenses), the sagittal and curvature powers can be similar. For a given wavefront W, at a radial distance r from a line perpendicular to the center of the wavefront (typically the center of the lens), W(r) = A*r 2 where A is a function. The curvature power is TIFF2025536204000002.tif10150, and for a simple spherical lens, TIFF2025536204000003.tif9150. Sagittal refractive power is TIFF2025536204000004.tif9150, and for a simple spherical lens, TIFF2025536204000005.tif9150. Therefore, for a simple lens with a spherical wavefront, under the paraxial assumption, Pc = Ps.

[0059] However, in some recently developed myopia control lenses employing "non-coaxial optics," the tilt and curvature power values ​​can differ significantly from one another. These lenses have surface regions that focus light from an on-axis source onto an area off the optical axis, and the distance at which local ray bundles are focused can be significantly different from the distance at which they intersect the optical axis. For these types of lenses, the distinction between sagittal (axial) power and curvature (local) power becomes important. For non-coaxial optics, a description of curvature power alone does not provide a complete description of the optical system. Adjacent regions of a lens may have the same fixed curvature power but do not have a fixed sagittal power (rays from each region intersect the optical axis at a distance different from the local focal length and from each other). For example, for lenses containing non-coaxial lenslets, the resulting sagittal and curvature power values ​​can differ significantly. A curvature power map of such a lens would show consistent add power for each lenslet, but a sagittal power map would show a drop-off in sagittal power with increasing radial distance.

[0060] Sagittal power is directly related to the position of the light rays at the image plane (the retinal surface of the eye), and therefore to image quality. When non-coaxial optical systems are implemented, these relationships do not generally exist for curvature power.

[0061] In practice, one exemplary manner for measuring the wavefront of light passing through an ophthalmic lens is to use an aberrometer, such as a Shack-Hartmann aberrometer. A Shack-Hartmann aberrometer contains a planar, regular array of small lenses. In use, the wavefront to be measured is sampled by a two-dimensional array of small lenses (lenslets), which focus different portions of the wavefront into different focal spots. When the wavefront is planar, the spatial arrangement of the resulting point spread function reflects the arrangement of the lenses, which thus focus the wavefront into a regular array of corresponding focal spots.

[0062] On the other hand, if the wavefront is tilted, the array of focal spots will be shifted in X and Y, and in the presence of other optical aberrations, the focal array will not replicate the geometry of the lenslet array. Rather, a portion of the wavefront that is non-planar arrives at the lens at an angle (i.e., not at normal incidence), and the lens focuses that portion of the wavefront to a focal spot that is laterally displaced from its position if the wavefront were planar. The size of the lateral shift depends on the average local tilt of the portion of the wavefront imaged by the lens with respect to the planar wavefront. The distance the focal point is shifted by the lens array provides a measure of the wavefront tilt at the corresponding portion of the wavefront.

[0063] The phase of the wavefront is typically estimated from discrete tilt measurements using numerical fitting or integration methods. A more common approach is to fit the tilt data using a set of polynomials that are derivatives of a set of basis functions (Zernike polynomials). The wavefront W(x,y) is expressed by the coefficients A series of k-polynomials of degree n with TIFF2025536204000006.tif6150 It is represented as TIFF2025536204000007.tif6150. The file is TIFF2025536204000008.tif11150.

[0064] Differentiating this equation gives the relationship between the slope of the wavefront and the derivative of the Zernike polynomial. TIFF2025536204000009.tif28170 TIFF2025536204000010.tif19170

[0065] coefficient TIFF2025536204000011.tif6150 is obtained by fitting differentiated Zernike polynomials to the measured wavefront slope using equations (2) and (3). The wavefront W(x,y) is then calculated using the coefficients obtained by fitting the first derivatives of the basis functions to the measured wavefront slope data. A set of Zernike basis functions with TIFF2025536204000012.tif6150 Calculated as TIFF2025536204000013.tif6150.

[0066] The second approach is typically applied to data that cannot be fitted by a polynomial (e.g., when the lens power profile has abrupt local changes) and uses numerical integration, for example, by calculating the value at a point from the values ​​at neighboring points and the rate of change of that value at the neighboring points.

[0067] The effect of a given lens on the wavefront is measured by inserting that lens into the measurement path at a position optically conjugate to the lenslet array.

[0068] Thus, the wavefront slope can be measured at intervals across the lens, for example across the optical zone of a contact lens. For example, to measure the wavefront slope every 104 μm across a 10 mm aperture, a single-pass Shack-Hartmann aberrometer with a 540 nm light source, such as the ClearWave® (available from www.lumetrics.com), can be used.

[0069] In the real world, the wavefront being measured will not be an ideal plane or spherical wavefront. An aberrometer's measurement of an optical wavefront is typically quantified by comparing it to a standard reference case, such as a plane wave or a spherical wave predicted from the known refractive power of the lens being measured. The former approach results in a wavefront error map that includes all the optical power and aberrations (low and high orders) of the lens.

[0070] However, the wavefront being measured is often known not to be planar even in theory, for example, because it is known to be a diverging or converging wavefront from a lens with negative or positive refractive power. Thus, in an aberrometer, the focal spot resulting from a converging or diverging wavefront is expected to be shifted from a normal array, and the lens aberrations can be isolated by subtracting the expected spherical wavefront from the measured wavefront. Specifically, in an aberrometer, the measured shift of the individual spot images can differ from the expected shift, and the wavefront error is calculated from the difference. The wavefront error map obtained by subtracting the expected spherical wavefront (resulting from a lens of a specified refractive power) from the measured wavefront does not include the optical power of the lens, but may include lower-order aberrations (e.g., prismatic, defocus, astigmatism) and higher-order aberrations (e.g., coma, spherical aberration).

[0071] As previously mentioned, numerical fitting or integration methods can be used to calculate a pupil wavefront error map from the measured wavefront tilt. The wavefront error map can be corrected for prism (which can be removed from the wavefront error data because it can corrupt the sagittal power calculation).

[0072] With the wavefront error map oriented so that the principal curvature directions are horizontal (x) and vertical (y), the wavefront error W(x,y) can be calculated using local horizontal and vertical gradients that can be obtained from the measured wavefront error, for example, using numerical differentiation methods. TIFF2025536204000014.tif10150. The sagittal power (i.e., tilt power or axial power) at each sample position is now the wavefront error tilt divided by the distance r of the sample position from the lens center. Thus, for example, the radial sagittal power is Defined as TIFF2025536204000015.tif9150.

[0073] where: The file is TIFF2025536204000016.tif6150.

[0074] The mean curvature power is defined as the local average curvature of the wavefront error, i.e. The file is TIFF2025536204000017.tif11150.

[0075] Laplacian operator TIFF2025536204000018.tif11150 averages the local curvature across all X and Y directions. The Laplacian curvature power is defined as twice the mean curvature. The Laplacian curvature of a sphere of a given radius will be twice the Laplacian curvature of a cylinder with the same radius (similarly, the mean curvature of a sphere will be twice the mean curvature of a cylinder).

[0076] The radial curvature power is Defined as TIFF2025536204000019.tif10150.

[0077] Similarly, the curvature refractive power in the circumferential direction (i.e., tangential direction) along the direction of the change angle θ perpendicular to the radius is Defined as TIFF2025536204000020.tif10150.

[0078] For example, consider a lens with a central region with spherical power and an annulus with additional power surrounding the central region. The annulus is a toroidal surface, not a spherical one, and the additional power is focused at off-axis rings rather than on the optical axis. The annulus has a greater radial curvature than a circumferential, or tangential, curvature. As previously mentioned, aberrometers typically subtract the spherical power of the lens. The remaining curvature exists radially across the annulus, and in the circumferential direction, the remaining curvature is flat (because the spherical curvature has been removed). A local x-y differentiator, such as a Laplacian operator, measures the average change in tilt. If the remaining circumferential curvature change after the spherical power is subtracted is zero, the measured power will be half the radial curvature. Therefore, the measured curvature power derived using the Laplacian operator is doubled to give the measured radial curvature power of the toroid.

[0079] In some embodiments of the present disclosure, each treatment region is tilted radially relative to the central region. As a result, each treatment region has a radial sagittal power profile that increases with increasing radial distance from the optical axis. The radial sagittal power profile of the central region may be generally flat. Alternatively, the radial sagittal power profile across the central region may have a curved profile. The radial sagittal power profile across the central region may have a quadratic or parabolic shape. As used herein, tilt of a treatment region refers to a radial tilt, not a lateral tilt. Thus, for example, in a radial cross-section of the lens, the outer edge of the arc defining the anterior surface of the first annular region may be displaced upward or downward from its position in the corresponding non-tilted treatment region. Correspondingly, in three dimensions, the circumferential boundary of the treatment area (formed by the ends of the radial arcs) may be displaced upward or downward from its position in a corresponding non-tilted treatment area. In practice, the tilt may be embodied in the optical design of the anterior surface of the treatment area of ​​the lens. Alternatively, the tilt may be embodied in the optical design of the posterior surface of the treatment area of ​​the lens, or in the optical design of both the anterior and posterior surfaces of the treatment area of ​​the lens.

[0080] Tilting a treatment region radially relative to the central region moves the center of curvature of the treatment region away from the optical axis. The greater the radial tilt relative to the central region, the greater the shift in the center of curvature of the treatment region, resulting in a steeper gradient of the radial sagittal power profile. Light rays passing through a radially tilted treatment region from a distant point source focus at an off-axis point rather than at a single point on the optical axis. For an annular treatment region with constant radial sagittal power, light rays passing through a radially tilted treatment region from a distant point source form an annular ring at the focal plane. The diameter of the annular ring depends in part on the tilt of the treatment region relative to the central region. The diameter of the annular ring also depends on the radial distance of the treatment region from the optical axis and the radial additive power of the treatment region.

[0081] In a lens with multiple concentric annular regions that provide focusing, light can be thought of as being "focused" by the multiple annular regions in two different ways.

[0082] In a first form of focusing, light is focused by the local curvature of the annular region. Considering a transverse 2D cross section through the lens, in the approximation of geometrical optics, adjacent light rays from a single distant light source passing through the radial width of the annular region (i.e., passing through a single "side" of the annular region, i.e., through a portion of the radius between the inner circumference of the annular region and the outer circumference of the annular region) are focused to a single point by the local curvature of the annular region, with multiple points from each radial width around the annular region forming a focal ring around the optical axis of the lens. This local focusing resulting from the local curvature within the radial width of the annular region is referred to herein as focusing, and the surface containing the focal ring is referred to as the focal plane. The curvature optical power of the annular region depends on the degree of (local) focusing.

[0083] In a second form of focusing, light is focused by the collective global curvature of one or more annular regions. Considering again a transverse 2D cross section through a lens, in the approximation of geometrical optics, a ray from a single distant light source passing through the midpoint of the radial width of an annular region travels in a direction determined by the radial position of the annular region on the lens and the radial "slope" of the annular region. The slope can be selected to ensure that rays passing through the radial width midpoints on opposite "sides" of the annular region converge to a single point on the optical axis. When a lens contains multiple annular regions, rays passing through the radial width midpoints of all the annular regions may converge to the same point. Light rays passing through the entire annular region (not just the midpoint) may converge to a small spot at this point. To more clearly distinguish it from the first form of focusing, this global focusing resulting from the lens curvature and the radial slope of the annular region is referred to herein as focusing, and the surface containing the point where the midpoints converge is referred to as the focusing surface. The sagittal power of the annular region depends on the (overall) degree of focusing.

[0084] As used herein, the terms focal plane and convergence plane do not refer to a physical surface, but rather to a plane that can be described through the point where light from a distant object is focused or reaches a local minimum spot size. The eye focuses light onto a curved retina. In a perfectly focused eye, the curvature of the surface matches the curvature of the retina. Therefore, the eye does not focus light onto a flat mathematical plane. Nevertheless, in the art, the curved surface of the retina is commonly referred to as a (planar) surface.

[0085] In some embodiments of the present disclosure, at least two of the multiple treatment regions may have different radial sagittal power profiles. At the boundary between the central region and the first innermost annular region, there may be a change in the gradient of the radial sagittal power profile. At the boundary between adjacent treatment regions, there may be a change in the gradient of the radial sagittal power. The annular region may include 2 to 10 concentric treatment regions, preferably 4 to 8 concentric treatment regions. Each treatment region may have a different radial sagittal power profile. Alternatively, alternating treatment regions may have the same radial sagittal power profile. The radial sagittal power profile of each treatment region may have a gradient of about 0.5 D / mm to about 20.0 D / mm, preferably about 0.5 D / mm to about 10.0 D / mm, and more preferably about 1.0 D / mm to about 5.0 D / mm. The first, innermost treatment region (i.e., closest to the central region) may have a first radial sagittal power profile gradient. A second adjacent treatment region may have a second, different radial sagittal power profile gradient, and a third treatment region adjacent to the second treatment region may have the same radial sagittal power profile gradient as the first treatment region. The first, innermost treatment region (i.e., closest to the central region) may have a first radial sagittal power profile gradient, and a second adjacent treatment region may have a second, greater radial sagittal power profile gradient. The radial sagittal power profile gradient of any or all of the treatment regions may depend on the radial distance of the treatment region from the first optical axis. Treatment regions that are a greater radial distance from the first optical axis may have a greater radial sagittal power profile gradient than treatment regions that are a smaller radial distance from the optical axis. Treatment regions at greater radial distances from the first optical axis may have a greater radial sagittal power profile slope and a greater radial width than treatment regions at smaller radial distances from the optical axis.

[0086] Tilting a treatment region radially relative to the central region changes the radial sagittal power profile of the treatment region, since it is a function of the first derivative of the wavefront, while the radial curvature power of the treatment zone does not change, since it is a function of the second derivative of the wavefront.

[0087] For lenses according to some embodiments of the present disclosure, the central region may have a substantially flat radial sagittal power profile. The radial sagittal power of the central region will be equal to the radial curvature power of the central region, which may hereinafter be referred to as the base power of the central region. The radial sagittal power across the central region may have a curved profile. The radial sagittal power profile across the central region may have a parabolic or quadratic shape.

[0088] Lenses according to some embodiments of the present disclosure have a nominal distance power (typically the power listed on the contact lens packaging). The nominal distance power of the lens depends on the location of the best distal focal plane, which in turn depends on the path of light rays from a distant point source passing through the treatment areas. As previously mentioned, light rays from a distant point source passing through the midpoint of the radial width of each treatment area (i.e., halfway through the radial width of each treatment area) will converge to a point contained in a focal plane centered on the optical axis. As a first approximation, the best distal focal plane can be defined as the focal plane where the spot size of light passing through the radial width of each treatment area is smallest. The location of this best distal focal plane determines the nominal distance power of the lens.

[0089] For lenses used to treat myopia, the nominal distance power of the lens is negative or near zero. The nominal distance power can be between +0.5 diopters (D) and -15.0 D. The nominal distance power can be between -0.25 D and -15.0 D.

[0090] For lenses according to some embodiments of the present disclosure, the central region may have a base power that is approximately equal to the nominal distance power. The central region may have a base power that is less (i.e., less positive or more negative) than the nominal distance power. The central region may have a radial sagittal power that varies according to the curve profile. The average radial sagittal power across the central region may be approximately equal to the nominal distance power, or may be less (i.e., less positive or more negative) than the nominal distance power. The average radial sagittal power across the central region may be greater (i.e., more positive or less negative) than the nominal distance power.

[0091] For lenses according to some embodiments of the present disclosure, at least one treatment zone may have a radial curvature power greater than the nominal distance power of the lens. Each treatment zone may have a radial curvature power greater than the nominal distance power of the lens. Thus, each treatment zone may provide a radial curvature add power. Hereinafter, the difference between the radial curvature power of each treatment zone and the nominal distance power may be referred to as the radial curvature add power or curvature add power.

[0092] Increasing the radius of curvature of a treatment region changes the radial curvature power of that treatment region, since it is a function of the second derivative of the wavefront. The radial curvature power of each treatment region can be determined by the curvature of at least one surface of the annular region. The radial curvature power of each treatment region can result from the curvature of the anterior and / or posterior surfaces of the lens. Each treatment region can have a larger curvature, i.e., a smaller radius of curvature, than the central region. The anterior surface of each treatment region can have a larger curvature, i.e., a smaller radius of curvature, than the central region. Alternatively or additionally, the posterior surface of each treatment region can have a larger curvature than the central region.

[0093] The nominal distance power of the lens may be positive, and each treatment zone may have a curvature power that is more positive than the nominal distance power, such that light from a distant point source passing through each treatment zone is focused toward an add-power focal plane that is closer to the lens than the distance focal plane.

[0094] The nominal distance power of the lens can be negative, and each treatment zone can have a curvature power that is less negative than the nominal distance power, or each treatment zone can have a positive curvature power. Considering a lens positioned on the cornea, if the curvature power of a treatment zone is less negative than the base power, light passing through that treatment zone from a distant point source will be focused toward an add focal plane that is further forward of the eye than the distance focal plane. Considering a lens not positioned on the cornea, if the curvature power of a treatment zone is positive, the add focal plane will be on the opposite side of the lens (the image side) from the distance focal plane (which will be a virtual focal plane on the object side of the lens), and if the curvature power of a treatment zone is negative (but less negative than the nominal distance power), the virtual add focal plane will be farther from the lens than the virtual distance focal plane.

[0095] For lenses according to some embodiments of the present disclosure, the radial curvature power of the central region may be equal to or approximately equal to the nominal distance power. In this case, when the lens is on the eye, light from a distant point source passing through the central region may be focused to a spot on the first optical axis at the distal focal plane. Alternatively, the central region may have a radial curvature add power that is less than the nominal distance power. In this case, when the lens is on the eye, light from a distant point source passing through the central region may be focused to a spot on the first optical axis that is closer to the lens than the distal focal plane.

[0096] The first innermost treatment region may have a first radial curvature power value that is greater (i.e., more positive or less negative) than the nominal distance power. When the lens is positioned on the eye, the first innermost treatment region may focus light from a distant point source toward a focal plane closer to the lens than the distal focal plane.

[0097] Each treatment zone may have a different radial curvature add power. The radial curvature power of a first, innermost treatment zone may have a first value, and the radial curvature power of a second adjacent treatment zone located a greater radial distance from the first optical axis may have a second, greater value. This may improve the lens wearer's vision. Alternatively, the second treatment zone located a greater radial distance from the first optical axis may have a second, smaller value. The first, innermost treatment zone may have a radial curvature add power of +0.5D to +20.0D, preferably about +2.0D to +10.0D, and more preferably about +1.0D to +5.0D. The second adjacent treatment zone may have a greater radial curvature add power of +0.5D to +20.0D, preferably +4.0D to +20.0D. The radial curvature add power of the treatment zones may alternate between high and low radial curvature add power values, with the high radial curvature add power value being greater than the nominal distance power of the lens. The high and low radial curvature add power values ​​may both be greater than the nominal distance power of the lens. The high radial curvature add power may be between +4.0D and +20.0D. The low radial curvature add power may be between +1.0D and +5.0D. For an on-eye lens, a high radial curvature add power treatment zone will focus light from a distant point source toward a near focal plane closer to the lens than a distal focal plane. A treatment area of ​​low radial curvature add power will focus light from a distal point source towards an intermediate focal plane that is between the near and distal focal planes.

[0098] Alternatively, each treatment zone may have the same radial curvature add power. The radial curvature add power of each treatment zone may be greater than the nominal distance power.

[0099] At the boundary between adjacent treatment areas, there may be an abrupt, discontinuous increase or decrease in radial curvature add power, depending on the relative radial curvature add power of the treatment areas.

[0100] At the boundaries between adjacent treatment zones, there may be abrupt, discontinuous increases or decreases in radial sagittal power. At the midpoint of the radial width of the first, innermost treatment zone, the radial sagittal power may match the nominal distance power of the lens. At the midpoint of the radial width of any or all of the treatment zones, the radial sagittal power may match the nominal distance power of the lens.

[0101] The radial sagittal power may be the same at the midpoint of the width of each treatment area.

[0102] There may be a steep increase in radial sagittal power at any of the boundaries between adjacent treatment areas. The radial sagittal power at the midpoint of the radial width of each treatment area will be less than the radial curvature power of that treatment area. At least one treatment area may be a sagittal add treatment area having a radial sagittal power greater than the nominal distance power of the lens across the width of the treatment area. In each treatment area, the radial curvature power may be greater than the radial sagittal power across the width of the treatment area. The sagittal add treatment areas are radially tapered such that the radial sagittal power is greater than the nominal distance power of the lens across the width of the treatment area. The radial sagittal power across the width of the sagittal add treatment area will be less than that of a coaxial or on-axis treatment area having the same radial curvature add power. In these treatment areas, light from a distant point source passing through the radial midpoint of the treatment area will be focused toward a sagittal add focal plane, which in the case of an on-eye lens will be closer to the lens than its distal focal plane.

[0103] Contact lenses may include elastomer materials, silicone elastomer materials, hydrogel materials, or silicone hydrogel materials, or combinations thereof. As understood in the contact lens field, a hydrogel is a material that retains water in equilibrium and does not contain silicone-containing compounds. A silicone hydrogel is a hydrogel that contains silicone-containing compounds. As described in the context of this disclosure, hydrogel and silicone hydrogel materials have an equilibrium water content (EWC) of at least 10% to about 90% (wt / wt). In some embodiments, hydrogel or silicone hydrogel materials have an EWC of about 30% to about 70% (wt / wt). By comparison, as described in the context of this disclosure, silicone elastomer materials have a water content of about 0% to less than 10% (wt / wt). Typically, silicone elastomer materials used in the present methods or devices have a water content of 0.1% to 3% (wt / wt).Examples of suitable lens formulations (compositions) include those having the following United States Adopted Names (USAN): methafilcon A, ocufilcon A, ocufilcon B, ocufilcon C, ocufilcon D, omafilcon A, omafilcon B, comfilcon A, enfilcon A, stenfilcon A, fanfilcon A, etafilcon A, senofilcon A, senofilcon B, senofilcon C, senofilcon D ... Senofilcon A, Senofilcon B, Senofilcon C, Narafilcon A, Narafilcon B, Balafilcon A, Samfilcon A, Lotrafilcon A, Lotrafilcon B, Somofilcon A, Riofilcon A, Delefilcon A, Verofilcon A, Kalifilcon A, and the like.

[0104] Alternatively, the lens may comprise, consist essentially of, or consist of a silicone elastomer material. For example, the lens may comprise, consist essentially of, or consist of a silicone elastomer material having a Shore A hardness of 3 to 50. Shore A hardness may be determined using conventional methods (e.g., using method DIN 53505), as understood by those skilled in the art. Other silicone elastomer materials may be obtained, for example, from NuSil Technology or Dow Chemical Company.

[0105] According to a second aspect, the present disclosure provides a method of manufacturing a lens. The method may include forming a contact lens. The contact lens comprises an optic zone including a central region, the central region having a first optical axis, a base radial sagittal power, a center of curvature lying on the first optical axis, and a diameter less than 2.0 mm. The optic zone includes an annular region having a plurality of treatment zones, each treatment zone having a radial sagittal power profile that increases with increasing distance from the optical axis.

[0106] The lens may include any of the features described above in relation to the first aspect of the invention.

[0107] The manufacturing method may include forming a female member having a concave lens-forming surface and a male member having a convex lens-forming surface. The method may include filling a gap between the female member and the male member with bulk lens material. The method may further include curing the bulk lens material to form a lens.

[0108] Contact lenses can be formed using a lathing process. Lenses can be formed by a casting process, a spin-casting process, or a lathing process, or a combination thereof. As understood by those skilled in the art, casting refers to the process of forming a lens by placing a lens-forming material between a female mold member having a concave lens-forming surface and a male mold member having a convex lens-forming surface.

[0109] FIG. 1A shows a schematic plan view of a prior art lens for use in slowing the progression of myopia (e.g., myopia correction). FIG. 1B shows a schematic cross-sectional side view of the lens of FIG. 1A. Lens 1 includes an optical zone 2, which generally covers the pupil, and a peripheral zone 4, which is located above the iris. The peripheral zone 4 provides mechanical functions, including increasing the size of the lens to make it easier to handle, providing ballast to prevent rotation of the lens 1, and providing a geometric region that improves comfort for the wearer of the lens 1. The optical zone 2 provides the optical function of lens 1, and includes an annular region 3 and a central region 5. In this lens 1, the central region 5 has a base curvature power corresponding to the distance power of the lens 1. The annular region 3 has a radial curvature power greater than the base curvature power of the central region 5. FIG. 2A is a schematic ray diagram illustrating how the lens 1 of FIGS. 1A and 1B focuses light when positioned on the eye. The focal point 11 of the annular region 3 is on a proximal focal plane 13, and the focal point 15 of the central region 5 is on a distal focal plane 17, which is further away from the rear surface of the lens 1. The focal point 11 of the annular region 3 and the focal point 15 of the central region 5 share a common optical axis 19. As shown in Figures 2A and 2C, for a point source at infinity, the light rays focused by the central region 5 form a focused image 23 at the distal focal plane 17. As shown in Figures 2A and 2B, the light rays focused by the central region 5 also produce an out-of-focus blur spot 27 at the proximal focal plane 13.

[0110] As shown in Figures 2A and 2B, light rays focused by the annular region 3 form an on-axis focused image 21 at the proximal focal plane 13. The light rays focused by the annular region 3 diverge after the proximal focal plane 13, and the diverging light rays produce a defocused (unfocused) annular (ring-shaped) image 25 at the distal focal plane 17, as shown in Figures 2A and 2C. As previously mentioned, the defocused annular image 25 can result in the wearer of the lens 1 seeing a "halo" around a focused distance image. The annular region 3 of the lens 1 of Figures 1A-2C can be referred to as a coaxial annular region 3 because light rays passing through the annular region 3 from a distant point source are focused to a spot on the optical axis 19.

[0111] 3A and 3B show schematic plan views of another known lens 101. Similar to lens 1 shown in FIGS. 1A and 1B, lens 101 includes an optic zone 102 and a peripheral zone 104 surrounding optic zone 102. Optical zone 102 includes a central region 105 and a first annular region 103 surrounding central region 105. As shown in FIGS. 4A and 4D, central region 105 has a center of curvature that is on optical axis 19. First annular region 103 is tilted radially relative to central region 105. First annular region 103 has an off-axis center of curvature that is a first distance from optical axis 19. The anterior surface of first annular region 103 has a greater curvature than the anterior surface of central region 105, thus providing a curvature power greater than the base curvature power of central region 105. 4D is a partial ray diagram of the lens 101 of FIGS. 3A and 3B as it is positioned on the eye. Circles are shown indicating the radii of curvature of the central distance region (solid line) and the annular additional region (dashed line) of the lens 101. As shown in FIG. 4D, the anterior surface of the central region 105 defines a portion of the surface of a sphere of larger radius 109. The annular region 103 defines a curved annular surface of smaller radius 106.

[0112] 4A and 4C show the light pattern at the distal focal plane 117 of the lens 101 of FIGS. 3A and 3B formed from a distant point source when the lens 101 is positioned on the eye. At the distal focal plane 117, light rays passing through the central region 105 are focused. Light rays passing through the midpoint of the width of the annular region 103 are focused to the same point as light rays passing through the central region 105. The annular region 103 acts as an optical beam stop, which results in a small spot size 133 of light at the distal focal plane 117.

[0113] 4B shows the light pattern at the near focal plane 113 of the lens 101 of FIGS. 3A and 3B formed from a distant point source when the lens 101 is positioned on the eye. No single image is formed at the near focal plane 113. At the near focal plane 113, for a point source at infinity, light rays passing through the central region 105 produce a blur circle 128. Meanwhile, light rays from a distant point source passing through the annular region 103 produce an annular ring 122, which surrounds the blur circle 128, as shown in FIG. 4B. FIG. 4B shows the light pattern produced for a distant point source.

[0114] 1A and 1B, lens 101 of Figures 2A and 2B does not produce a single image or an on-axis image at the near focal plane 113, which could be used to avoid the need for the eye to accommodate to near objects. For distant extended objects, the image formed at the near focal plane 113 is the convolution of (i) a focused image of the extended object that would be obtained with a conventional lens having the refractive power of an annular region and (ii) an optical transfer function that describes the optical effect of the annular region 103.

[0115] 1A and 1B, no annular or "halo" effect occurs at the far focal plane 117. The annular region 103 of the lens 101 of Figures 3A and 3B may be referred to as a non-coaxial annular region 103 or an off-axis annular region 103 because light rays passing through the annular region 103 from a distant point source are not focused to a spot on the optical axis 119.

[0116] FIG. 5A shows a comparison between the radial sagittal power profile 231 (dashed line) of a lens having two coaxial or on-axis annular regions of additional power spanning widths 203, 203′ (i.e., annular regions that focus light from a distant point source toward an axial spot), and the radial sagittal power profile 233 (solid line) of a lens having two non-coaxial or off-axis annular regions of additional power spanning widths 203, 203′ (i.e., annular regions that do not focus light toward an axial spot). 5B shows a corresponding comparison between the radial curvature power profile 232 (dashed line) of a lens having two coaxial or on-axis add-power annular regions spanning the widths 203, 203′ and the radial curvature power profile 234 (solid line) of a lens having two non-coaxial or off-axis add-power annular regions spanning the widths 203, 203′. The radial sagittal power and radial curvature power in diopters (D) are plotted as a function of radial distance from the center (r=0) of the lens. Both lenses have flat radial sagittal power and radial curvature power profiles throughout the central region 205. For a coaxial or on-axis lens, at the boundary between the central region 205 and the first annular region 203, there is a steep increase in radial sagittal power 231 and a steep increase in radial curvature power 232, with the radial sagittal power 231 and radial curvature power profile 232 being constant across the width of the annular region 203. For a non-coaxial lens, at the boundary between the central region 205 and the first annular region 203, there is a steep increase in radial curvature power 234 and a steep decrease in radial sagittal power 233. For a non-coaxial lens, the radial tilt of the annular region 203 relative to the central region 205 results in the radial sagittal power 233 increasing at a constant gradient across the radial width of the annular region 203. For non-coaxial lenses, at the midpoint of the width of the annular region 203, the radial sagittal power 233 matches the radial sagittal power 233 across the central region 205, which in this case corresponds to the distance power of the lens. Both lenses have a second annular region positioned at a greater radial distance from the center of the lens.Both lenses have the same radial curvature power 232, 234 across the annular regions 203, 203′. For a coaxial lens, the radial sagittal power 231 across the width 203′ of the second annular region is substantially the same as the radial sagittal power 231 across the first annular region 203. For a non-coaxial lens, less radial sagittal add power is required to achieve the same radial curvature power, and so the slope of the radial sagittal power profile 233 across the second annular region 203′ is less than its slope across the first annular region 203. Both lenses have a distance-power region 207 between the first annular region 203 and the second annular region 203′ that has substantially flat radial sagittal power profiles 231, 233 and substantially flat radial curvature power profiles 232, 234. The radial curvature powers 232, 234 across the distance-power region 207 match the radial curvature powers 232, 234 across the central region 205.

[0117] FIG. 6A shows a schematic plan view of a lens 301 according to one embodiment of the present disclosure. FIG. 6B shows a schematic cross-sectional view of the lens 301 of FIG. 6A. The lens 301 includes an optical zone 302, which generally covers the pupil, and a peripheral zone 304, which is located above the iris. The peripheral zone 304 provides mechanical functions, including increasing the size of the lens to make it easier to handle, providing ballast to prevent rotation of the lens 301, and providing a geometric region that improves comfort for the wearer of the lens 301. The optical zone 302 provides the optical functions of the lens 301. The optical zone 302 includes a small central region 305 having a diameter of 0.5 mm and an annular region 303 surrounding the central region 305. The annular region 303 includes two concentric treatment regions 303a, 303b. Each treatment region 303a, 303b is radially angled relative to the central region 305. Each treatment zone 303a, 303b provides a radial curvature add power. For this lens 301, the radial curvature add power results from the greater curvature of the anterior surface of the lens 301. The inner treatment zone 303a has a lower radial curvature add power, and the outer treatment zone 303b has a higher radial curvature add power.

[0118] Figure 7 shows the radial sagittal power profile 331 and the radial curvature power profile 332 along the radius of the lens 301 shown in Figures 6A and 6B. Across the width of the central region 305, the radial sagittal power profile 331 is flat. Across the width of the central region 305, the radial sagittal power 331 is equal to the radial curvature power 332. For the lens 601 of Figures 6A and 6B, the radial sagittal power 331 and the radial curvature power 332 across the central region 305 are more negative than the nominal distance power of the lens (indicated by the dashed line 330).

[0119] At the boundary between the central region 305 and the inner treatment region 303a, there is an increase in radial curvature power 332. The inner treatment region 303a has a greater curvature than the central region 305, and therefore provides an additional radial curvature power. The radial curvature power 332 is generally constant across the width of the inner treatment region 303a. At the boundary between the inner treatment region 303a and the outer treatment region 303b, there is an even steeper increase in radial curvature power 332. The outer treatment region 303b has a greater curvature than the innermost treatment region 303a, and therefore provides a greater additional radial curvature power.

[0120] Across the inner treatment region 303a, the radial sagittal power 331 increases with a constant positive gradient. At the midpoint of the radial width of each treatment region 303a, 303b, the radial sagittal power 331 matches the nominal distance power of the lens 303. The gradient of the radial sagittal power profile 331 across the outer treatment region 303b is greater than the gradient across the inner treatment region 303a.

[0121] Figure 8 is a schematic partial ray diagram (not to scale) illustrating how the treatment regions 303a, 303b of the lens 301 of Figures 6A and 6B focus light when the lens 301 is positioned on an eye. Light passing from a distant point source through a small central region 305 is focused to a spot on the optical axis 319 of the central region focal plane 318. Both the inner treatment region 303a and the outer treatment region 303b are radially tilted with respect to the central region 305, so that light passing from a distant point source through the treatment regions 303a, 303b is not focused to a single spot on the optical axis 319. Light rays from a distant point source passing through the midpoint of the radial width of each treatment region 303a, 303b focus at a focusing plane 317 that intersects the optical axis 319. The focusing plane 317 is positioned behind the lens 301 when the lens 301 is positioned on the eye. This focusing plane 317 is the best distance focal plane and determines to a first approximation the nominal distance power of the lens 301. For the lens 301 of Figures 6A and 6B, the nominal distance power is greater than the radial curvature power of the central region 305, so the best distance focal plane is further in front of the eye compared to the central region focal plane 318.

[0122] 6A and 6B, each treatment region 303a, 303b has a radial curvature power that is greater than the nominal distance power and the radial curvature power of the central region 305. Thus, light passing through the treatment regions 303a, 303b from a distant point source is focused toward surfaces 341, 343 that are more anterior to the eye than the nominal distance focal plane 317 and the central region focal plane 318. The radial curvature power profile is generally constant across the width of each treatment region 303a, 303b.

[0123] The innermost treatment zone 303a has a low radial add power. Therefore, the focal plane 341 of light rays passing through the treatment zone 303a from a distant point source is shifted closer to the lens 301 than the distal focal plane 317. The inner treatment zone 303a is tilted radially relative to the central zone 305. Therefore, light rays passing through the treatment zone 303a from a distant point source are not focused to a single spot on the optical axis 319. Instead, light rays passing through the innermost treatment zone 303a from a distant point source form an annular ring 337 at the low add focal plane 341.

[0124] The outer treatment region 303b, positioned adjacent to the inner treatment region 303a and at a greater radial distance from the optical axis 319, has a higher radial add curvature power than the inner treatment region 303a. Thus, this outer treatment region 303b focuses light from a distant point source toward a high add focal plane 343 that is closer to the lens 301 compared to the distal focal plane 317 and the low add focal plane 341. The outer treatment region 303b is also tilted with respect to the central region 305, so that light passing through the second treatment region 303b from a distant point source is not focused toward a spot on the optical axis 319, but forms an annular ring 339 at the high add focal plane 343.

[0125] FIG. 9A shows a schematic plan view of a lens 401 according to another embodiment of the present disclosure. FIG. 9B shows a schematic cross-sectional view of the lens 401 of FIG. 9A. The lens 401 includes an optical zone 402, which generally covers the pupil, and a peripheral zone 404, which is located above the iris. The peripheral zone 404 provides mechanical functions, including increasing the size of the lens 401 to make it easier to handle, providing ballast to prevent rotation of the lens 401, and providing a geometric region that improves comfort for the wearer of the lens 401. The optical zone 402 provides the optical functions of the lens 401. The optical zone 402 includes a small central region 405 having a diameter of 0.5 mm and an annular region 403 surrounding the central region 405. The annular region 403 includes two concentric treatment regions 403a, 403b. Both treatment regions 403a, 403b are radially angled relative to the central region 405. Both treatment regions 403a, 403b have a radial curvature power that is greater than the radial curvature power of the central region 405 and greater than the nominal distance power of the lens 401. For this lens 401, each treatment region 403a, 403b provides the same radial add-on curvature power relative to the central region 405.

[0126] 10 shows the radial sagittal power profile 431 and the radial curvature power profile 432 along the radial direction of the lens 401 shown in FIGS. 9A and 9B. Across the width of the central region 405, the radial sagittal power profile 431 and the radial curvature power profile 432 are flat. Across the width of the central region 405, the radial sagittal power 431 is equal to the radial curvature power 432, which may hereinafter be referred to as the base power. For the lens 401 of FIGS. 9A and 9B, the base power is equal to the nominal distance power of the lens (indicated by the dashed line 430).

[0127] At the boundary between the central region 405 and the inner treatment region 403a, there is a steep increase in radial curvature power 432. The inner treatment region 403a has a greater curvature than the central region 405, and therefore provides radial additive curvature power. The radial curvature power 432 is constant across the width of the innermost treatment region 403a. At the boundary between the inner treatment region 403a and the outer treatment region 403b, there is no change in radial curvature power 432. The outer treatment region 403b has the same radial additive curvature power as the inner treatment region 403a.

[0128] At the boundary between the central region 405 and the inner treatment region 403a, there is a steep decrease in the radial sagittal power 431, and across the inner treatment region 403a, the radial sagittal power 431 increases with a constant positive slope. At the boundary between the inner treatment region 403a and the outer treatment region 403b, there is an even steeper decrease in the radial sagittal power 431. The slope of the radial sagittal power profile 431 is smaller across the outer treatment region 403b because at greater radial distances from the optical axis, less radial sagittal power is required to produce the same radial curvature power.

[0129] Figure 11 is a schematic partial ray diagram (not to scale) illustrating how the treatment regions 403a, 403b of the lens 401 of Figures 9A and 9B focus light when the lens 401 is positioned on an eye. Light passing from a distant point source through a small central region 405 is focused to a spot on the optical axis 419 of the central region focal plane 418. Both the inner treatment region 403a and the outer treatment region 403b are radially tilted with respect to the central region 405, so that light passing from a distant point source through the treatment regions 403a, 403b is not focused to a single spot on the optical axis 419. Light rays from a distant point source passing through the midpoint of the radial width of each treatment region 403a, 403b focus at a focusing plane 417 that intersects the optical axis 419. The focusing plane 417 is positioned behind the lens 401 when the lens 401 is positioned on the eye. This focal plane 417 is the best far focal plane and determines to a first approximation the nominal distance power of the lens 401. For the lens 401 of Figures 9A and 9B, the best far focal plane coincides with the central region focal plane 418.

[0130] 9A and 9B, both treatment regions 403a, 403b have the same radial add power curvature. As a result of the radial add power curvature, light passing through treatment region 403a or treatment region 403b from a distant point source is focused onto add power focal plane 441, which is closer to lens 401 than distal focal plane 417.

[0131] This innermost treatment region 403a is tilted radially relative to the central region 405, so that light rays passing through this treatment region 403a from a distant point source are not focused to a single spot on the optical axis 419. Instead, as shown in Figure 11, light rays passing through the innermost treatment region 403a from a distant point source form an annular ring 437 at the additional optical power focal plane 441.

[0132] The outer treatment region 403b is tilted with respect to the central region 405 and with respect to the inner treatment region 403a. Light rays passing through the outer treatment region 403b from a distant point source are not focused to a single spot on the optical axis 419, but instead form an annular ring 439 at the additional optical power focal plane 441. Because the outer treatment region 403b is positioned at a greater radial distance from the optical axis than the inner treatment region 403a and the relative radial tilts of the inner treatment region 403a and outer treatment region 403b are different, the diameter of the annular ring 439 formed from light passing through the outer treatment region 403b is larger than the diameter of the annular ring 439 formed from light passing through the inner treatment region 403a.

[0133] FIG. 12A shows a schematic plan view of a lens 501 for use in slowing the progression of myopia (e.g., myopia correction) according to another embodiment of the present disclosure. FIG. 12B shows a schematic cross-sectional view of the lens 501 of FIG. 12A. The lens 501 comprises an optical zone 502, which generally covers the pupil, and a peripheral zone 504, which is located above the iris. The peripheral zone 504 provides mechanical functions, including increasing the size of the lens to make it easier to handle, providing ballast to prevent rotation of the lens 501, and providing a geometric region that improves comfort for the wearer of the lens 501. The optical zone 502 provides the optical functions of the lens 501. The optical zone 502 includes a small central region 505 having a diameter of 0.5 mm and an annular region 503 surrounding the central region 505. The annular region 503 includes two concentric treatment regions 503a, 503b. Both treatment areas 503a, 503b are radially tilted relative to the central region 505, and both treatment areas 503a, 503b provide radial curvature add power relative to the central region 505 and to the nominal distance power of the lens 505.

[0134] Figure 13 shows the radial sagittal power profile 531 and the radial curvature power profile 532 along the radial direction of the lens 501 shown in Figures 12A and 12B. Across the width of the central region 505, the radial sagittal power profile 531 and the radial curvature power profile 532 are flat. Across the width of the central region 505, the radial sagittal power 531 is equal to the radial curvature power 532. For the lens 501 of Figures 12A and 12B, the radial sagittal power 531 and the radial curvature power 532 across the central region 505 are more negative than the nominal distance power of the lens (indicated by the dashed line 530).

[0135] Both treatment zones 503a, 503b have a radial curvature power 532 that is greater than the nominal distance power. At the boundary between the central zone 505 and the inner treatment zone 503a, there is a steep increase in the radial curvature power profile 532. The inner treatment zone 503a has a curvature that is greater than the nominal distance power of the central zone 505 and the lens 5051, and therefore provides radial curvature power additive. The radial curvature power 532 is constant across the width of the innermost treatment zone 503a. At the boundary between the inner treatment zone 503a and the outer treatment zone 503b, there is a further increase in the radial curvature power 532. The outer treatment zone 503b has a greater radial curvature power additive than the inner treatment zone 503a.

[0136] Across the innermost treatment region 503a, the radial sagittal power 531 increases at a constant positive gradient. The outer treatment region 503b is tilted relative to the central region 505 and is also tilted relative to the inner treatment region 503a. The radial sagittal power 531 is greater across the width of the outer treatment region 503b than across the width of the inner treatment region 503a. Across the width of the outer treatment region 503b, the radial sagittal power 531 increases at a constant positive gradient. Across the width of the outer treatment region 503b, the radial curvature power 532 of the outer treatment region 503b is greater than the radial sagittal power 531.

[0137] Figure 14 is a schematic partial ray diagram (not to scale) illustrating how the treatment regions 503a, 503b of the lens 501 of Figures 12A and 12B focus light when the lens 501 is positioned on an eye. Light passing through a small central region 505 from a distant point source is focused to a spot on the optical axis 519 of the central region focal plane 518. Both the inner treatment region 503a and the outer treatment region 503b are radially tilted with respect to the central region 505, so that light passing through the treatment regions 503a, 503b from a distant point source is not focused to a single spot on the optical axis 519. Light rays from a distant point source passing through the midpoint of the radial width of the treatment regions 503a, 503b focus at a focusing plane 517 that intersects the optical axis 519. The focusing plane 517 is positioned behind the lens 501 when the lens 501 is positioned on the eye. This converging plane 517 is the best distance focal plane and determines to a first approximation the nominal distance power of the lens 501. For the lens 501 of Figures 12A and 12B, the nominal distance power is less negative than the radial curvature power of the central region 505, so the best distance focal plane 517 is closer to the lens 501 than the central region focal plane 518.

[0138] 12A and 12B, the inner treatment region 503a has a radial curvature power that is greater than the nominal distance power and the radial curvature power of the central region 505, but less than the radial curvature power of the outer treatment region 503b. As a result, light passing through the inner treatment region 503a from a distant point source is focused toward a low-add power focal plane 541, which is closer to the lens 501 than the distal focal plane 517 and the central region focal plane 518. The inner treatment region 503a is radially tilted relative to the central region 505, such that light passing through the inner treatment region 503a from a distant point source forms an annular ring 537 at the low-add power focal plane 541. The outer treatment region 503b is angled relative to the central region 505 and the inner treatment region 403a, such that the outer treatment region 503b has a radial sagittal power across its width that is greater than the radial sagittal power across the inner treatment region 403a. Light rays passing from a distant point source through the radial midpoint of the outer treatment region 503b (i.e., the midpoint of the radial width of the outer treatment region 403b) are focused to a point 544 on the optical axis at the sagittal add power focusing surface 545. Light rays passing from a distant point source through the outer treatment region 503b are focused toward a high add power focal plane 543, which is closer to the lens 501 than the low add power focal plane 541, the distal focal plane 417, and the central region focal plane 518. The outer treatment region 503b is radially tilted relative to the central region 505 so that light passing through the outer treatment region 503b from a distant point source forms an annular ring 539 at the high add power focal plane 541.

[0139] FIG. 15 is a flowchart illustrating a method 660 of manufacturing a contact lens according to one embodiment of the present disclosure. The contact lens comprises an optic zone including a central region having a first optical axis, a base radial sagittal power, a center of curvature lying on the first optical axis, and a radial (radial) diameter that is less than 0.5 mm. The optic zone includes an annular region having a plurality of treatment zones, each having a radial sagittal power profile that increases with increasing distance from the optical axis. The lens may include any of the features previously described. In a first step 661, the method includes forming a female member having a concave lens-forming surface and a male member having a convex lens-forming surface. In a second step 663, the method includes filling a gap between the female member and the male member with bulk lens material. In a third step 665, the method includes curing the bulk lens material to form the lens.

[0140] In alternative embodiments of the present disclosure, the lens may be formed using a lathing process, a casting process, a spin-casting process, or multiple lathing processes, or combinations thereof.

[0141] Those skilled in the art will appreciate that features of these exemplary embodiments may be combined in other embodiments within the scope of the present disclosure.

[0142] In the exemplary embodiment of the present disclosure described above in Figures 6A-14, the contact lens includes two concentric treatment regions. In other embodiments, the contact lens may include more than two concentric treatment regions. For example, the contact lens may include between two and ten concentric treatment regions. In the exemplary embodiment of the present disclosure described above in Figures 6A-14, the treatment regions have approximately the same radial width. In other embodiments, the treatment regions may have different radial widths.

[0143] In some embodiments of the present disclosure, the coaxial and non-coaxial regions of the contact lens may have the same curvature power, while in other embodiments, the coaxial and non-coaxial regions of the contact lens may have different curvature powers.

[0144] Where the foregoing description refers to integers or elements that have known, obvious, or foreseeable equivalents, such equivalents are hereby incorporated by reference as if individually set forth herein. Reference should be made to the claims to determine the true scope of the present disclosure. The claims should be construed to embrace all such equivalents. The reader will also understand that any integers or features of the present disclosure described as advantageous, convenient, or the like are optional and do not limit the scope of the independent claims. Furthermore, it should be understood that such optional integers or features may be beneficial in some embodiments of the present disclosure, but may be undesirable in other embodiments and, therefore, may not be present in other embodiments.

Claims

1. A contact lens, a central region; an annular region; an optical zone comprising the central region has a first optical axis, a center of curvature that lies on the first optical axis, and a diameter that is less than 2.0 mm; the annular region having a plurality of concentric treatment regions; Each treatment region has a radial sagittal power profile that increases with increasing radial distance from the optical axis. A contact lens characterized by:

2. At least two of the plurality of treatment regions have different radial and sagittal power profiles.

2. The contact lens of claim 1.

3. The annular region has 2 to 10 concentric treatment regions.

3. The contact lens according to claim 1 or 2.

4. Each of the plurality of concentric treatment regions has a different radial and sagittal power profile.

4. The contact lens according to claim 1.

5. Each treatment area has a radial width of about 0.1 to 2.5 mm.

5. The contact lens according to claim 1.

6. Each treatment area has a radial sagittal power gradient of between about 0.5 D / mm and about 20.0 D / mm.

6. The contact lens according to claim 1.

7. Nominal distance power of +0.5D to -15.0D 7. The contact lens according to claim 1.

8. At least one treatment area has a radial curvature power greater than the nominal distance power of the lens.

8. The contact lens of claim 7.

9. Each treatment area has a radial curvature power greater than the nominal distance power of the lens.

8. The contact lens of claim 7.

10. The curvature power of the central region is equal to the nominal distance power.

10. The contact lens according to claim 1.

11. The nominal distance power of the lens is greater than the curvature power of the central region.

10. The contact lens according to claim 1.

12. Alternating concentric treatment areas provide higher and lower radial curvature powers; The higher radial curvature power is greater than the nominal distance power of the lens.

12. A contact lens according to any one of claims 7, 8, 10 and 11.

13. The lower radial curvature add power is greater than the nominal distance power of the lens.

13. The contact lens of claim 12.

14. Each treatment zone provides a radial curvature add power of +2.5D to +10.0D 13. A contact lens according to any one of claims 7 to 10 and 12.

15. At a midpoint of the radial width of an innermost treatment area of ​​the plurality of treatment areas, the radial sagittal power of the treatment area matches the nominal distance power of the lens.

15. The contact lens according to claim 1.

16. At the midpoint of the radial width of each treatment area, the radial sagittal power of the treatment area matches the nominal distance power of the lens.

16. The contact lens of claim 15.

17. At least one treatment area is a sagittal add treatment area having a radial sagittal power greater than the nominal distance power of the lens across the radial width of the treatment area.

16. The contact lens according to claim 1.

18. a generally flat radial sagittal power profile across the central region; 18. A contact lens according to any one of claims 1 to 17.

19. a radial sagittal power profile across the central region that is curved; 19. A contact lens according to any one of claims 1 to 18.

20. the radial sagittal power profile across the central region has a quadratic or parabolic shape; 20. The contact lens of claim 19.

21. The radial curvature power of each treatment area results from the curvature of the anterior and / or posterior surfaces of the lens.

21. The contact lens according to any one of claims 1 to 20.

22. The lens comprises an elastomeric material, a silicone elastomeric material, a hydrogel material, or a silicone hydrogel material, or a mixture thereof.

22. The contact lens according to claim 1.

23. The lens is formed using a lathing or casting process.

23. The contact lens according to any one of claims 1 to 22.

24. A method for manufacturing a contact lens, comprising: A process for forming a contact lens according to any one of claims 1 to 23. A method comprising:

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