Ophthalmic lenses and methods relating thereto

Abstract

This invention describes a lens (1) and a method (1000) for manufacturing an ophthalmic lens. The lens (1) includes an optical region. The optical region includes a central region (5) having a curvature centered on an optical axis (19), the central region (5) providing a radial curvature power for hyperopia correction. The central region (5) has a radial sagittal power distribution that increases with increasing radial distance from the optical axis (19). The gradient of the radial sagittal power distribution across the central region (5) follows a first curve that increases with increasing radial distance from the optical axis (19). A first annular region (3) circums the central region (5). The first annular region (3) provides an additional radial curvature power.

Description

Technical Field

[0001] The present invention relates to ophthalmic lenses. In particular, but not exclusively, the present invention relates to ophthalmic lenses for slowing the progression of myopia. The present invention also relates to methods of making such lenses. Prior Art

[0002] Many people, both children and adults, require ophthalmic lenses to correct myopia (short-sightedness).

[0003] Uncorrected myopia focuses incoming light from distant objects onto a location in front of the retina. Consequently, the light converges toward a plane in front of the retina and diverges toward the retina, becoming out of focus upon reaching the retina. Conventional lenses used to correct myopia (e.g., spectacle lenses and contact lenses) reduce the convergence (for contact lenses) or cause divergence (for spectacle lenses) of incoming light from distant objects before it reaches the eye, shifting the location of the focal point onto the retina.

[0004] Decades ago, it was proposed that the progression of myopia in children or young adults could be slowed or prevented by undercorrecting (i.e., shifting the focus toward the retina but not completely onto it). However, this approach inevitably results in decreased distance vision compared to the vision achieved with a lens that fully corrects myopia. Furthermore, there are doubts about whether undercorrection is effective in controlling developing myopia. A newer approach to correcting myopia is to provide lenses with both one or more areas of full correction that provide distance vision and one or more areas of undercorrection or intentionally induced myopic defocus. This approach has been proposed to prevent or slow the development or progression of myopia in children or young adults while providing good distance vision.

[0005] In the case of a lens with a region that provides defocus, the region that provides full correction for distance vision may be referred to as a hyperopic correction region, and the region that provides undercorrection or intentionally induced myopic defocus is often referred to as a myopic defocus region, therapeutic region, or addition region (because the refractive power is more positive or less negative than that of the hyperopic region). A surface (usually the front surface) of the addition region(s) has a smaller radius of curvature than that of the hyperopic region(s), thereby providing a more positive or less negative power to the eye. The addition region(s) are designed to focus incoming parallel light (i.e., light from a distance) into the eye in front of the retina (i.e., closer to the lens), while the hyperopic region(s) are designed to focus light and form an image at the retina (i.e., farther from the lens).

[0006] One known type of contact lens for reducing myopia progression is a bifocal contact lens available commercially under the name MISIGHT (CooperVision). This bifocal lens differs from bifocal or multifocal contact lenses designed to improve vision in people with presbyopia in that it is configured with specific optical dimensions to enable an adapted person to use distance vision correction (i.e., base power) for viewing both distant and near objects. The treatment area of ​​the bifocal lens with the add-on power also provides a myopic defocused image at both distant and near viewing distances.

[0007] While these lenses have been found to be beneficial in preventing or slowing the development or progression of myopia, the annular addition area may produce undesirable visual side effects. Light focused in front of the retina by the annular addition area diverges from the focal point to form a defocused ring at the retina. As a result, wearers of these lenses may see a ring or "halo" surrounding the image formed on the retina, particularly around small, bright objects such as streetlights and car headlights.

[0008] Further lenses have been developed that can be used to treat myopia and are designed to eliminate the halos observed around focused distance images in MISIGHT (CooperVision) lenses and other similar lenses described above. In these lenses, the annular region is configured so that no single on-axis image is formed in front of the retina, thereby preventing this image from being used to avoid requiring the eye to accommodate near objects. Instead, a distant point light source is imaged by the annular region onto an annular focal line at a near-addition focal plane, resulting in a small spot size of light on the retina at a far-sighted focal plane without a surrounding "halo" effect.

[0009] The present invention seeks to provide an improved lens for introducing additional myopic defocus and benefiting from the improved image quality achieved by the off-axis imaging technique as described above. Summary of the Invention

[0010] According to a first aspect, the present invention provides an ophthalmic lens. The lens comprises an optical zone. The optical zone includes a central region having a curvature centered on an optical axis. The central region provides a degree of radial curvature for hyperopia correction and has a radial sagittal power profile that increases with increasing radial distance from the optical axis. The gradient of the radial sagittal power profile across the central region follows a first curve, increasing with increasing radial distance from the optical axis. The optical zone includes a first annular region circumscribing the central region. The first annular region provides a radial curvature add power.

[0011] According to a second aspect, the present invention provides a method for manufacturing an ophthalmic lens. The method includes providing a spherical aberration power profile, the spherical aberration power profile being a variation in the sagittal power of an eye as a function of radial distance from an optical axis of the eye. The method includes providing a target sagittal power profile for a lens wearer, the target sagittal power profile being a target variation in the sagittal power as a function of radial distance from an optical axis of the lens wearer's eye, wherein the target sagittal power profile includes a central region having a base radial curvature power and a first annular region providing an add power of radial curvature. The method includes subtracting the spherical aberration power profile from the target sagittal power profile to produce a corrected sagittal power profile. The method includes manufacturing an ophthalmic lens having the corrected sagittal power profile.

[0012] Of course, it should be understood that features described with respect to one aspect of the present invention may be incorporated into other aspects of the present invention. For example, the method of the present invention may incorporate features described with respect to the apparatus of the present invention, and vice versa. Simple diagram description

[0013] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which:

[0014] FIG1A is a schematic top view of a first known ophthalmic lens (a Type A lens) having an annular treatment zone that provides a myopic defocused image to reduce myopia progression;

[0015] Figure 1B is a side view of the contact lens of Figure 1A;

[0016] Figure 2A is a light diagram of the lens of Figure 1A;

[0017] Figure 2B shows a light pattern formed by a distant point source at a proximal focal plane of the lens of Figure 1A;

[0018] Figure 2C shows a light pattern formed by a distant point source at a distal focal plane of the lens of Figure 1A;

[0019] FIG3 is a ray diagram of a portion of the lens of FIG1A and FIG1B , and a circle indicating the radius of curvature of the central distance vision area (dotted line) and the annular additional area (dashed line) of the lens;

[0020] Figure 4A is a plot showing changes in the radial sagittal power of the lens shown in Figures 1A and 1B;

[0021] Figure 4B is a plot showing the change in the radial curvature degree of the lens shown in Figures 1A and 1B;

[0022] FIG5A is a ray diagram of a second known lens (a type B lens) for reducing myopia progression having non-coaxial optics;

[0023] Figure 5B shows a light pattern formed by a distant point source at a proximal focal plane of the lens of Figure 5A;

[0024] Figure 5C shows a light pattern formed by a distant point source at a distal focal plane of the lens of Figure 5A;

[0025] FIG5D is a ray diagram of a portion of the lens of FIG5A , and a circle indicating the radius of curvature of the central distance vision area (dotted line) and the annular additional area (dashed line) of the lens;

[0026] Figure 6A is a plot showing changes in the radial sagittal power of the lens shown in Figure 5A;

[0027] Figure 6B is a plot showing the change in the radial curvature degree of the lens shown in Figure 5A;

[0028] FIG7A is a partial ray diagram of a third conventional lens (a C-type lens) for reducing myopia progression, and circles indicating the radii of curvature of the central far vision zone (dash-dotted line) and the annular additional zone (dashed line) of the lens;

[0029] Figure 7B shows a light pattern formed by a distant point source at a distal focal plane of the lens of Figure 7A;

[0030] Figure 7C shows a light pattern formed by a distant point source at a first proximal focal plane of the lens of Figure 7A;

[0031] Figure 7D shows a light pattern formed by a distant point source at a second proximal focal plane of the lens of Figure 7A;

[0032] Figure 8A is a plot showing the change in the radial curvature degree of the lens shown in Figure 7A;

[0033] Figure 8B is a plot showing the change in the radial sagittal power of the lens shown in Figure 7A;

[0034] Figure 9 shows a plot showing the change in radial sagittal power of a first lens according to one embodiment of the present invention;

[0035] Figure 10 is a plot showing the change in the radial sagittal power of a second lens according to an embodiment of the present invention; and

[0036] FIG. 11 is a flow chart showing a method of manufacturing an ophthalmic lens according to an embodiment of the present invention. Implementation Method

[0037] According to a first aspect, the present invention provides an ophthalmic lens. The lens comprises an optical zone. The optical zone includes a central region centered on an optical axis. The central region provides a degree of radial curvature for hyperopia correction and has a radial sagittal power profile that increases with increasing radial distance from the optical axis. The gradient of the radial sagittal power profile across the central region follows a first curve, increasing with increasing radial distance from the optical axis. The optical zone includes a first annular region circumscribing the central region. The first annular region provides a radial curvature add power.

[0038] An ophthalmic lens can be a contact lens or a spectacle lens. 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 a contact lens will provide clinically acceptable supraorbital movement and will not bind to one or both eyes. An ophthalmic lens can be in the form of a corneal lens (e.g., a lens that rests on the cornea of ​​the eye). An ophthalmic lens can be a soft contact lens, such as a hydrogel contact lens or a silicone hydrogel contact lens. An ophthalmic lens can be a lens used to prevent or slow the development or progression of myopia. The lens can be used to provide an extended depth of focus for a myopic eye. A spectacle lens can comprise PMMA, CR-39, polycarbonate, Trivex, or crown glass.

[0039] An ophthalmic lens according to the present invention includes an optical zone. The optical zone encompasses the optically functional portion of the lens. The optical zone is configured to be positioned above the pupil of an eye during use. For an ophthalmic lens according to the present invention, the optical zone includes a central region and one or more first annular regions circumscribing the central region.

[0040] The optic zone may be surrounded by a peripheral zone. The peripheral zone is not part of the optic zone. For embodiments of the present invention in which the ophthalmic lens is a contact lens, the peripheral zone may be located outside the optic zone and above the iris when the lens is worn, and may provide a mechanical function, such as increasing the size of the lens to make it easier to handle, providing ballasting to prevent lens rotation, and / or providing a shaped area to improve wearer comfort. The peripheral zone may extend to the edge of the contact lens. The peripheral zone may have a substantially circular outer periphery. In embodiments of the present invention in which the lens is a spectacle lens, the peripheral zone may be located outside the optic zone and may have a substantially circular outer periphery. The peripheral zone may extend to the edge of the spectacle lens. The peripheral zone may be surrounded by another zone that provides a mechanical function.

[0041] For embodiments of the present invention in which the ophthalmic lens is a contact lens, the peripheral zone may include a weight to orient the lens when positioned on a wearer's eye. Embodiments of the present invention incorporating a weight into a contact lens will rotate to a predetermined repose angle under the action of the wearer's eyelid when placed on the wearer's eye. For example, the weight may be a wedge, and the rotation may be caused by the action of the eyelid on the wedge. Adding weight to a contact lens to orient a contact lens is well known in the art; for example, toric contact lenses are weighted to orient the lens so that the orthogonal cylindrical correction provided by the lens is properly aligned with the wearer's astigmatism. It may be the case that the contact lens of the present invention provides a particular benefit to the wearer in a given orientation.

[0042] In embodiments of the present invention wherein the ophthalmic lens is a spectacle lens, the lens may be substantially circular in shape. The lens may be elliptical in shape. The lens may be oval in shape. The lens may be rectangular in shape. The lens may be square in shape. The front surface of the lens may have an area between 1200 mm² and 3000 mm².

[0043] In embodiments of the present invention in which the ophthalmic lens is a contact lens, the lens may be substantially circular in shape and may have a diameter ranging from about 3 mm to about 20 mm, preferably from about 13 mm to about 15 mm. The optic zone of the ophthalmic lens may be substantially circular in shape and may have a diameter ranging from about 3 mm to about 10 mm, preferably from about 7 mm to about 9 mm.

[0044] The optical axis of a lens is defined with reference to a distant point source. Light from a distant point source on the optical axis of the lens (hereinafter referred to as an on-axis distant point source) will be focused onto the optical axis of the lens. The optical axis may lie along the centerline of the lens. For example, when the lens is a contact lens, the optical axis typically lies along the centerline of the lens. However, the optical axis may not lie along the centerline of the lens; this may be the case with spectacle lenses, where the position of the lens's optical axis is determined by the wearer's interpupillary distance, which, depending on the lens geometry, may not coincide with the centerline of the lens.

[0045] In basic ray optics, a ray of light from a distant object passing through a simple lens intersects the optical axis at a focal point located at a specific distance from the lens. The power of the lens is the reciprocal of this distance. Because the power of a lens defined in this way can be calculated from the point where the ray intersects the optical axis, it is sometimes called the "axial power."

[0046] In a wave optics interpretation of focusing, the focal point where a ray normal to the wavefront intersects the optical axis is determined by the slope (i.e., first derivative) of the wavefront after it passes through the lens. Therefore, the degree that is still the reciprocal of the distance to the focus is sometimes called the "slope degree."

[0047] In a simple lens, the focal point where a ray normal to the wavefront intersects the optical axis can also be derived from the lens's curvature. Specifically, it is related to the curvature of the wavefront after it passes through the lens (i.e., its second derivative). Therefore, the degree that is still the inverse of the distance to the focal point is sometimes also called the "curvature" degree. For a simple lens, this is equal to the slope degree and is simply the lens's power, as commonly understood in basic optics.

[0048] Therefore, for a simple lens, the "power", "axis power", "slope power" and "curvature power" are all the same.

[0049] Lenses that are not simple lenses may have more than one power, and therefore a qualification of the term "power" is necessary.

[0050] In the presence of astigmatism, in an otherwise simple lens, light rays do not intersect the optical axis at a single point, but rather form two orthogonal line foci. The reciprocal of the distances to these two line foci means that the lens has two powers: sagittal and tangential. In the relevant plane, the sagittal power is still simply the power of the lens (in that plane), as is commonly understood in basic optics.

[0051] However, as optical surfaces become more complex, the different ways in which "power" can be defined begin to become important. Specifically, light rays from different parts of the optical surface can intersect each other at different points, and therefore you can identify different powers.

[0052] Alternatively, you can consider the point where the light rays intersect the optical axis, as before, and define the power as the inverse of the distance to that point. This is obviously the lens's "axial power": it is defined by the position where the light rays intersect the optical axis. It is also the lens's "slope power": it can be derived from the slope of the wavefront. In the appropriate plane, it is the lens's "sagittal power," as that term is commonly understood.

[0053] Alternatively, consider the point where light rays passing through a small area of ​​the lens intersect. This point can be considered a local focus, and it will generally not lie on the optical axis of the lens. Obviously, the value of this local power will differ from the axial power, and therefore also from the slope and sagittal powers. However, this local power arises from the local curvature of the optical surface and still depends on the curvature of the wavefront passing through that local area. It is equivalent to the "curvature power" defined above. It is sometimes also called the "instantaneous power" because it is the power of an infinitesimally small area of ​​the surface. For obvious reasons, it is also sometimes called the "local power."

[0054] It should be noted that the slope, a first-order derivative of the wavefront, is also a property that can vary from point to point on an optical surface, but it has a different value than the curvature, which is a second-order derivative of the wavefront. The slope is the reciprocal of the distance at which rays passing through a point cross the optical axis of the lens. The curvature is the reciprocal of the distance at which rays passing through a point near each other cross each other.

[0055] In general optics, the term "sagittal" is used to describe oblique astigmatism. Oblique astigmatism occurs when light rays originating from an off-axis position pass through a lens at an angle. Astigmatism is primarily due to cosine compression occurring in the meridian along which the light rays originate. For example, if the light rays originate from the horizontal peripheral field, the surface (and therefore the radius of curvature) will exhibit cosine compression horizontally, resulting in an increase in power (and therefore astigmatism) in that meridian. Powers in that meridian are labeled "tangential" power, and powers in the perpendicular meridian are labeled "sagittal" power. Astigmatism causes an object point to be imaged at two spatially separate and orthogonal line foci: the sagittal focal line and the tangential focal line.

[0056] The word "sagittal" is also used to describe optical surfaces. For example, in ophthalmology, it is the center of clinical measurement of the anterior ocular surface (i.e., in corneal topography). Sagittal optical power is determined by the slope of the optical surface along a given direction; it is also called slope-based power. As discussed above, the terms "sagittal power," "slope power," and "axial power" are used interchangeably to describe the optical power of a lens surface at the point where a ray passing through the surface intersects the optical axis. Curvature power is determined by the local curvature of the optical surface along a given direction.

[0057] In the present invention, the term "sagittal" is used in the context of an optical surface to describe the sagittal power of a surface of an ophthalmic lens. It also describes the curvature power of an ophthalmic lens. Both sagittal power and curvature power are defined along a given direction. For ophthalmic lenses according to embodiments of the present invention, radial sagittal and radial curvature power are defined along a direction extending radially outward from the optical axis of the lens. Circumferential sagittal and circumferential curvature power are defined along a direction perpendicular to the radial direction. However, for some recently developed myopia control lenses that utilize non-coaxial optics, the values ​​of sagittal power or slope power and curvature power can differ significantly from each other. These lenses have surface regions that focus light from an on-axis light source onto an area displaced from the optical axis, such that a localized beam from the light source reaches a focus at a distance that is significantly different from the distance at which it intersects 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 does not provide a complete description of the optic. Adjacent regions of a lens may have the same curvature power but different sagittal powers (because light rays from each region intersect the axis at different distances from the local focal length and from each other). For example, for a lens containing non-coaxial lenslets, the resulting sagittal power values ​​and curvature power values ​​differ significantly. A curvature power plot for such a lens shows a constant add power for each lenslet, but a sagittal power plot reveals a sagittal power that decreases with increasing radial distance.

[0058] The sagittal power is directly related to the position of the rays at the image plane (the retinal plane in the eye) and therefore directly related to the image quality. When implementing non-coaxial optics, the curvature power is not necessarily the same.

[0059] The sagittal and curvature powers of an ophthalmic lens can be determined by measuring the wavefront of light passing through the lens. When describing the optical wavefront that has passed through a lens, the sagittal power of a lens at a given point is related to the first derivative of the wavefront, calculated as the slope of the wavefront divided by the radial distance (r) from the optical axis of the lens (usually the center of the lens). The radial (local) curvature power at that point is calculated as the second derivative of the wavefront.

[0060] In practice, one exemplary approach for measuring the wavefront of light passing through an ophthalmic lens is to use an aberrometer, such as a Shack-Hartmann aberrometer with a (monochromatic, i.e., narrowband) 540 nm light source, such as the ClearWave® (available from www.lumetrics.com). A Shack-Hartmann aberrometer comprises a planar, regular array of mirrorlets. In use, the wavefront to be measured is sampled by a two-dimensional array of mirrorlets (lenses), each of which focuses a different portion of the wavefront to a different focal spot. If the wavefront is planar, the spatial configuration of the resulting point spread function will reflect the configuration of the lens, so the lens will focus the wavefront to a focal spot corresponding to the regular array.

[0061] Aberrometer-derived measurements of an optical wavefront are typically quantified relative to a standard reference. For example, when using a Shack-Hartmann aberrometer, the standard reference is typically a plane wavefront passing through a two-dimensional array of mirrors (lenses) as described above.

[0062] The effect of a given lens on the wavefront is measured by inserting the lens into the measurement path at a position optically conjugate with the lenslet array. A plane wavefront then passes through the two-dimensional array of lenslets and through the lens.

[0063] For a simple lens, the resulting wavefront will be a diverging or converging wavefront generated by an array of equally displaced points relative to the lens in its absence. In practice, the magnitude and direction of the point displacements can also be caused by additional aberrations in the lens. A wavefront error map is determined by measuring the displacement of the focal spot from a regular array of offset points, and this wavefront error map can be used to calculate the sagittal and curvature powers of the lens.

[0064] The wavefront phase is usually estimated from discrete slope measurements using numerical fitting methods or numerical integration. A more common approach is to fit the slope data with a series of polynomials that are themselves derivatives of a set of basis functions, known as Zernike polynomials. The system is represented as a A series of n-order k polynomials ,therefore:

[0065] Differentiating this expression provides the relationship between the slope of the wavefront and the differentials of the Zernike polynomials:

[0066] coefficient It is obtained by fitting the differentiated Zernike polynomials to the measured wavefront slope using (2) and (3). Calculated to have coefficients obtained by fitting the first derivative of the basis function to the measured wavefront slope data A series of Zernike basis functions .

[0067] A second method, often applied to data that cannot be fitted by a polynomial (for example, in the case of a lens power distribution with sudden local changes), uses numerical integration, for example calculating the value at a point from the values ​​at nearby points and the rate of change of the value at the nearby points.

[0068] The effect of a given lens on the wavefront is measured by inserting the lens into the measurement path at a position optically conjugate to the lenslet array.

[0069] Thus, the wavefront slope and error map can be measured across the lens (e.g., across the optical zone of a contact lens). For example, a single-sided Shack-Hartmann aberrometer (such as the ClearWave® (available from [www.lumetrics.com])) to measure the wavefront slope every 104 µm across a 10 mm aperture.

[0070] In the real world, measured wavefronts are not ideally planar or spherical. As explained above, aberrometer-derived measurements of optical wavefronts are typically quantified relative to a standard reference condition (typically a plane wave or a spherical wave expected from a known power of a measured lens). This method results in a wavefront error map that includes all optical powers and aberrations (lower and higher orders) of a lens.

[0071] Typically, even in theory, it's known that the measured wavefront is non-planar, for example, because it's known to be a diverging or converging wavefront, for example, from a lens with a negative or positive power, respectively. Therefore, in an aberrometer, the focus obtained from a converging or diverging wavefront is expected to deviate from a regular array, and the aberrations of a lens can be isolated by subtracting the expected spherical wavefront from the measured wavefront. Specifically, in an aberrometer, the measured deviations of individual spot images will differ from the expected deviations, and the wavefront error is calculated from these differences. The wavefront error map obtained by subtracting the expected spherical wavefront (attributable to a lens of a given power) from the measured wavefront does not include the optical power of the lens, but may include lower-order aberrations (prism, defocus, and astigmatism) and higher-order aberrations (e.g., coma and spherical aberration).

[0072] If the wavefront is tilted, the focal spot array will be offset in X and Y, and in the presence of other optical aberrations, the focal array will not replicate the lenslet array geometry. Instead, a portion of a non-planar wavefront will arrive at a lens at an angle (i.e., not at normal incidence), and the lens will therefore focus that portion of the wavefront to a focal spot that is laterally offset from its position if the wavefront were planar. The magnitude of this lateral offset depends on the average local slope of the portion of the wavefront imaged by the lens relative to a planar wavefront. Therefore, the distance by which the lens array offsets the focal spot provides a measure of the wavefront slope at the corresponding portion of the wavefront.

[0073] As discussed above, numerical fitting or numerical integration methods can be used to calculate a wavefront error map of the pupil from the measured wavefront slope. The wavefront error map can be corrected for prisms (which can be removed from the wavefront error data because they can corrupt the calculation of sagittal power).

[0074] In the case where the wavefront error map is oriented so that the principal curvature directions are horizontal (x) and vertical (y), the wavefront error W(x, y) has local horizontal and vertical slopes that can be obtained from the measured wavefront error, for example, using numerical differentiation The sagittal power (i.e., slope power or axial power) at each sampled position is here the wavefront error slope divided by the distance r from the sampled position to the lens center; thus, for example, the sagittal power is defined as

[0075] in .

[0076] The mean curvature degree is defined as the local mean curvature of the wavefront error, i.e. .

[0077] Laplace operator Average the local curvature across all X and Y directions. The degree of Laplace curvature is defined as twice the mean curvature. The Laplace curvature of a sphere of a given radius will be twice the Laplace curvature of a cylinder of the same radius. (Similarly, the mean curvature of a sphere will be twice the mean curvature of a cylinder.)

[0078] The degree of radial curvature is defined as:

[0079] Similarly, along the changing angle perpendicular to the radius The degree of circular (or tangential) curvature in the direction of is defined as:

[0080] For example, consider a lens with a central region having a spherical power and an annulus surrounding the central region with an addition power, where the annulus is a torus rather than a surface of a sphere. That is, the addition power is focused not to a point on the optical axis but to a ring of off-axis points. In an annulus, the radial curvature will be greater than the circumferential or tangential curvature. As described above, an aberrometer typically subtracts the spherical power of the lens. The remaining curvature is in the radial direction across the annulus; in the circumferential direction, the curvature is flat (because the spherical curvature has been removed). A local xy differentiator such as the Laplace operator measures the average change in slope; in cases where the residual circumferential change in curvature is zero after subtracting the spherical power, the measured power will therefore be half the radial curvature. Therefore, the measured curvature power derived using the Laplace operator is doubled to obtain the measured radial curvature power of the annulus.

[0081] Thus, for the lenses described herein and in accordance with embodiments of the present invention, the sagittal power (i.e., slope power or axial power) at a given location is the first derivative of the wavefront error (i.e., the wavefront error slope, which can be obtained, for example, from a wavefront error map) with respect to r divided by r, where r is the radial distance of that location from the optical axis of the lens; thus, the sagittal power is defined as .

[0082] Furthermore, for the lenses described herein and in accordance with embodiments of the present invention, the degree of radial curvature at a given location is the second derivative of the wavefront error (which can be obtained, for example, from a wavefront error map) with respect to r, where r is the radial distance of that location from the optical axis of the lens; thus, the degree of radial curvature is defined as: .

[0083] An eye typically experiences spherical aberration. This spherical aberration can be spherical aberration of the lens and / or spherical aberration of the retina. Spherical aberration causes light rays passing through the periphery of the eye to focus at a different location than light rays passing through the center of the eye.

[0084] Spherical aberration can cause an eye's sagittal power to decrease with increasing radial distance from the eye's optical axis. This is often the case for young eyes (children and young adults). In cases where spherical aberration causes the sagittal power distribution of an eye to decrease with increasing radial distance from the eye's optical axis, lenses according to the present invention correct the spherical aberration of a lens wearer's eye. The amount of spherical aberration in a lens wearer's eye will vary depending on whether the eye is viewing distant or near objects. When the eye is in a non-accommodated state (i.e., when viewing distant objects), the effect of spherical aberration will be less than when the eye is in an accommodated state (i.e., when viewing near objects).

[0085] It should be noted that for other lens wearers (e.g., elderly individuals), the sagittal power profile of the lens of an eye may follow a curved profile that increases with increasing radial distance from the optical axis of the eye due to spherical aberration. Lenses according to the present invention do not correct spherical aberration in a lens wearer's eye that causes sagittal power to increase with increasing radial distance from the optical axis.

[0086] When a lens wearer wears an ophthalmic lens according to the present invention, the effective sagittal power experienced by the lens wearer will be the sum of the sagittal power of the eye and the sagittal power of the ophthalmic lens.

[0087] The central region of an ophthalmic lens according to the present invention may be substantially circular and may have a diameter between about 2 mm and 9 mm, and preferably between about 2 mm and about 4 mm. The central region may be substantially oval. The central region may be substantially elliptical.

[0088] The radial sagittal power and radial curvature power of the central area may be caused by a curvature of a surface of the lens. The radial sagittal power and radial curvature power of the central area may be caused by a curvature of a front surface of the lens and / or a center of curvature of a back surface of the lens.

[0089] In cases where the eye's spherical aberration causes a decrease in sagittal power with increasing radial distance from the eye's optical axis, the central zone of a lens according to the present invention corrects the spherical aberration of a lens wearer's eye. Across the radial width of the central zone, the sagittal power distribution increases with increasing radial distance from the lens' optical axis. The gradient of the sagittal power distribution follows a first curve, increasing with increasing radial distance from the optical axis, thereby compensating for the decrease in sagittal power caused by the lens wearer's spherical aberration.

[0090] Across the radial width of the central region, the sagittal power may increase by between 0.01 D and 3.0 diopters (D). The gradient of the sagittal power distribution across the central region may vary between 0 D / mm and 3.0 D / mm. For example, the gradient may increase from 0 D / mm to 0.8 D / mm as the distance from the optical axis increases, following a first curve.

[0091] The sagittal power distribution across the central region may have a profile that is the inverse of a curve that plots the decrease in sagittal power of a lens wearer's eye with increasing radial distance from the optical axis of the eye due to spherical aberration. The first curve may be a parabolic curve or may include a parabolic component. The first curve may increase or decrease smoothly and continuously with increasing radial distance from the optical axis of the lens. The gradient of the first curve may increase with increasing radial distance from the optical axis of the lens to compensate for the increase in spherical aberration of the lens wearer's eye with increasing radial distance from the optical axis of the eye.

[0092] Ophthalmic lenses used to treat myopia are typically designed to provide a lens wearer with a constant sagittal power profile and a constant radial curvature power across the central region of the lens. The central region of the lens is typically used for distance vision.

[0093] For lenses according to the present invention, the central region provides a degree of radial curvature for hyperopia correction. For lenses used to treat myopia, the degree of radial curvature for hyperopia correction will be negative or close to zero. The degree of radial curvature for hyperopia correction can be between +0.5 D and -25.0 D, preferably between +0.5 D and -15.0 D.

[0094] The degree of radial curvature for hyperopia correction may be constant across the central region. The radial sagittal power across the central region of the lens will increase with increasing radial distance from the optical axis to compensate for the decrease in radial sagittal power of a lens wearer's eye due to spherical aberration, and under perfect or ideal compensation, this may result in the lens wearer experiencing a constant radial sagittal power across the central region of the lens.

[0095] The nominal power of the central region will typically correspond to the marked power of the contact lens as provided on the contact lens packaging (although in reality, it may not have the same value). This will typically be the average power of curvature across the central region. The measured power of the central region is the average power of refractive curvature obtained by direct measurement across the central region. This may be different from the nominal power.

[0096] Typical lenses used to reduce myopia progression have at least one addition zone with a greater radial curvature addition power than a central zone. Hereinafter, the difference in radial curvature power between an addition zone and the central zone's radial curvature power for hyperopia correction may be referred to as a radial curvature addition power or a curvature addition power. In lenses according to the present invention, a first annular zone circumscribes the central zone and provides a radial curvature addition power.

[0097] The first annular region can provide an additional degree of radial curvature between +0.5 D and +20.0 D, preferably between +0.5 D and +10.0 D. The first annular region can provide an additional degree of radial curvature of +2.0 D, +3.0 D, +4.0 D, or +12.0 D. The first annular region can provide an additional degree of radial curvature of at least +10.0 D. The additional degree of radial curvature can be constant across the radial width of the first annular region.

[0098] The first annular region can provide a radial sagittal add power. Hereinafter, the difference in radial sagittal power between the add power region and the radial sagittal power at the radial midpoint of the central region may be referred to as a radial sagittal add power or sagittal add power. The radial sagittal power may be approximately constant across the radial width of the first annular region. The radial sagittal power across the first annular region may be a radial sagittal add power between +0.5 D and +20.0 D, preferably between +0.5 D and +4.0 D. The radial sagittal power across the first annular region may be a radial sagittal add power of +2.0 D or +3.0 D. At the boundary between the central region and the first annular region, the radial sagittal power may increase sharply. The sharp increase may be a sharp increase of +2.0 D. Alternatively, at the boundary between the central region and the first annular region, the radial sagittal power may decrease sharply. The sharp decrease may be a decrease of between 0.5 D and 2.5 D. The radial sagittal power may increase with increasing radial distance from the optical axis. The radial sagittal power may increase with increasing radial distance from the optical axis in a gradient between 1.0 D / mm and 20.0 D / mm. The radial sagittal power may increase with increasing radial distance from the optical axis in a gradient between 4.0 D / mm and 12.0 D / mm. The average radial sagittal power across the first annular region may be an add power between +0.5 D and +4.0 D (e.g., approximately +2.0 D or +3.0 D). The average radial sagittal add power across the first annular region may be zero.

[0099] In an embodiment of the present invention, the central region has a sagittal power profile that compensates for the spherical aberration profile of a lens wearer's eye. The first annular region may have a sagittal power profile that compensates for the spherical aberration profile of a lens wearer's eye. Alternatively, the first annular region may have a sagittal power profile that is uncorrected for spherical aberration. In this case, the first annular region of the lens may have a substantially flat sagittal power profile, or a sagittal power profile that increases with a constant gradient as the distance from the optical axis increases.

[0100] Across the radial width of the first annular zone, the radial sagittal power distribution may increase with increasing radial distance from the optical axis of the lens, thereby compensating for a decrease in radial sagittal power caused by spherical aberration of the lens wearer's eye. Across the radial width of the first annular zone, the gradient of the radial sagittal power distribution may follow a second curve, increasing with increasing radial distance from the optical axis, thereby compensating for a decrease in radial sagittal power caused by spherical aberration of the lens wearer's eye.

[0101] Across the radial width of the first annular region, the radial sagittal power may increase by between 0.01 D and 10.0 D. The gradient of the radial sagittal power distribution across the first annular region may be greater than 0 D / mm and less than 10.0 D / mm. The gradient of the radial sagittal power distribution across the first annular region may be between 1.0 D / mm and 20.0 D / mm. The gradient of the radial sagittal power distribution across the first annular region may be between 4.0 D / mm and 12.0 D / mm. The gradient of the radial sagittal power distribution across the first annular region may increase with increasing distance from the optical axis. For example, the gradient may increase from 0 D / mm to 1.9 D / mm, from 1.0 D / mm to 9.0 D / mm, or from 0.5 D / mm to 7.8 D / mm.

[0102] The radial sagittal power distribution across the first annular region may have a profile that is the inverse of a curve plotting the change in radial sagittal power of a lens wearer's eye as radial distance from the optical axis of the eye increases due to spherical aberration. The second curve may be a parabolic curve or may include a parabolic component. The second curve may increase smoothly and continuously with increasing radial distance from the optical axis of the lens. The gradient of the second curve may increase with increasing radial distance from the optical axis of the lens to compensate for the increase in spherical aberration of the lens wearer's eye as radial distance from the optical axis of the eye increases.

[0103] Lenses according to the present invention may be based on known lenses for reducing myopia progression, such as the type A, type B and type C lenses described below.

[0104] A first type of lens for reducing myopia progression (hereinafter referred to as an A-type lens) includes a central zone having a radial curvature power for hyperopia correction and a constant radial sagittal power across its radial width. The central zone may have a chord diameter between 2.5 mm and 4 mm. The central zone may have a chord diameter between 2.7 mm plus or minus 0.04 mm. A first annular zone circumscribes the central zone. The first annular zone provides a radial curvature addition power and a radial sagittal addition power matching the radial curvature addition power across the radial width of the first annular zone. The matching radial sagittal power may be +2.0 D or +3.0 D greater than the radial curvature power of the central zone. At the boundary between the central zone and the first annular zone, the radial sagittal power increases sharply, and the radial curvature power increases sharply. The radial sagittal power is constant across the width of the first annular zone, and the radial curvature power is constant. The first annular region may have a radial width between 0.5 mm and 1.5 mm. The first annular region may have a radial width of 0.7 mm plus or minus 0.01 mm.

[0105] A second lens for reducing myopia progression (hereinafter referred to as a Type B lens) includes a central region and a first annular addition power region surrounding the central region. The central region provides a degree of radial curvature for hyperopia correction and has a constant radial sagittal power across its radial width. The central region may have a chord diameter between 2.5 mm and 4 mm. A first annular region circumscribes the central region and provides a degree of radial curvature addition. The first annular region may have a radial width between 0.5 mm and 1.5 mm. At the boundary between the central region and the first annular region, the degree of radial curvature increases sharply. The radial curvature addition is constant across the radial width of the first annular region. The degree of radial curvature across the first annular region may be between +2.0 D and +12.0 D greater than the degree of radial curvature of the central region. The degree of radial curvature across the first annular region may be +2.0 D, +3.0 D, +4.0 D, +10.0 D, or +12.0 D greater than the degree of radial curvature of the central region. The first annular region is radially tilted relative to the central region, and therefore, the radial sagittal degree varies across the width of the first annular region. The radial sagittal degree increases with a positive, constant gradient across the radial width of the first annular region. The radial sagittal degree may increase with a gradient between 1.0 D / mm and 20.0 D / mm across the radial width of the first annular region. The radial sagittal degree may increase with a gradient between 4.0 D / mm and 12.0 D / mm across the radial width of the first annular region. Across the width of the first annular region, the radial sagittal degree may be less than the radial curvature degree. At the boundary between the central region and the first annular region, the radial sagittal degree may decrease sharply. The sharp decrease may be a decrease between 0.5 D and 2.5 D. The average radial sagittal power across the width of the first annular region may match the radial sagittal power at the radial midpoint of the central region (i.e., the average radial sagittal add power across the radial width of the first annular region may be zero). The radial sagittal power at a point halfway across the width of the annular region may match the radial sagittal power at the radial midpoint of the central region (i.e., the radial sagittal add power at a point halfway across the radial width of the first annular region may be zero).

[0106] A third lens for reducing myopia progression (hereinafter referred to as a C-type lens) includes a central region and a first annular region surrounding the central region. The central region provides a degree of radial curvature for hyperopia correction and has a constant radial sagittal power across its radial width. The central region may have a chord diameter between 2.5 mm and 4 mm. A first annular region circumscribes the central region. The first annular region may have a radial width between 0.5 mm and 1.5 mm. Similar to the B-type lens described above, the first annular region is radially inclined relative to the central region, and the radial sagittal power varies across the radial width of the first annular region. The radial sagittal power increases with a positive, constant gradient across the radial width of the first annular region. The radial sagittal power may increase with a gradient between 1.0 D / mm and 20.0 D / mm across the radial width of the first annular region. The radial sagittal power may increase with a gradient between 4.0 D / mm and 12.0 D / mm across the radial width of the first annular region. However, compared to the first and second lenses, this third lens also includes an additional radial-sagittal addition power in the first annular zone, resulting in a potential sharp increase in both radial-sagittal power and radial curvature power at the boundary between the central zone and the first annular zone. The sharp increase in radial-sagittal power at the boundary between the central zone and the first annular zone may be as much as +2.0 D. Across the width of the first annular zone, the radial-sagittal power is greater than the radial-sagittal power of the central zone (i.e., there is a radial-sagittal addition power across the radial width of the first annular zone, and this radial-sagittal addition power increases across the radial width of the first annular zone). At a point midway across the radial width of the first annular zone, the radial-sagittal power may be +3.0 D or +4.0 D greater than the radial-sagittal power of the central zone. At a point midway across the radial width of the first annular zone, the radial-curvature power may be between +2.0 D and +12.0 D greater than the radial-curvature power of the central zone. At a point halfway across the radial width of the first annular region, the degree of radial curvature may be +2.0 D, +3.0 D, +4.0 D, +10.0 D, or +12.0 D greater than the degree of radial curvature of the central region.

[0107] In the context of the present invention, the first annular region is a substantially annular region circumscribing the optic zone. It may have a substantially circular shape or a substantially elliptical shape. It may completely surround the optic zone. It may partially surround the optic zone.

[0108] The first annular region may extend radially outward from a perimeter of the central region by between about 0.1 mm and 4 mm, preferably between about 0.5 mm and 1.5 mm. For example, the radial width of the annular region may be between about 0.1 mm and about 4 mm, and preferably between about 0.5 mm and about 1.5 mm. The perimeter 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.

[0109] The first annular region may be adjacent to the central region. A mixing region may be provided between the central region and the first annular region. The mixing region should not substantially affect the optics provided by the central region and the annular region, and the mixing region may have a radial width of 0.05 mm or less, but in some embodiments, it may be as wide as 0.2 mm or as wide as 0.5 mm.

[0110] In an embodiment of the present invention, the first annular zone provides a radial curvature addition power. The first annular zone may also provide a radial sagittal addition power. The lens may be based on one of the three lens designs described above for reducing myopia progression (Type A, Type B, or Type C lenses) and may correct for a spherical aberration across at least the central zone of the lens. At the boundary between the central zone and the first annular zone, the radial curvature power may increase sharply, and the radial curvature power may be constant across the first annular zone. At the boundary between the central zone and the first annular zone, the radial sagittal power may increase sharply, or the radial sagittal power may decrease sharply. At the boundary between the central zone and the first annular zone, the gradient of the radial sagittal power distribution may change.

[0111] In embodiments of the present invention, a central zone is corrected for spherical aberration of a lens wearer's eye. A first annular zone may or may not be corrected for spherical aberration of the lens wearer's eye. The spherical aberration correction across the first annular zone may be based on the same spherical aberration profile, or spherical aberration curve, as the spherical aberration correction across the central zone. For example, the sagittal power profiles of both the central zone and the first annular zone may include a correction for spherical aberration based on the same curve when the lens wearer's eye is in a maladaptive state. Alternatively, the spherical aberration correction across the first annular zone may be based on a different spherical aberration profile, or spherical aberration curve, than the spherical aberration correction across the central zone. For example, the sagittal-sagittal power distribution of the central zone may include a correction for spherical aberration for an eye in an accommodating state based on a first curve, and the sagittal-sagittal power distribution of the first annular zone may include a correction for spherical aberration for an eye of a lens wearer in a non-accommodating state following a second, different curve.

[0112] In an embodiment of the present invention, an ophthalmic lens may be based on the type B lens described above and include a spherical aberration correction across at least the central region of the lens. The central region will include a spherical aberration correction as described above and will have a sagittal power profile that increases with increasing radial distance from the optical axis of the lens. The gradient of the sagittal power profile will follow a first curve that increases with increasing radial distance from the optical axis.

[0113] The first annular region will provide an additional degree of radial curvature. The degree of radial curvature may increase sharply at the boundary between the central region and the first annular region, and the degree of radial curvature may be approximately constant across the radial width of the annular region. The first annular region will be radially tilted relative to the central region. The radial sagittal power may decrease sharply at the boundary between the central region and the first annular region. Across the radial width of the first annular region, the radial sagittal power will increase with increasing radial distance from the optical axis due to the radial tilt of the annular region relative to the central region. The gradient of the radial sagittal power distribution may follow a second curve that increases with increasing radial distance from the optical axis due to both spherical aberration correction and the radial tilt of the annular region relative to the central region.

[0114] For these embodiments, a spherical aberration correction based on a first curve is applied to the central region. A spherical aberration correction based on a second curve can be applied to the first annular region. The first curve and the second curve can be the same. Alternatively, a spherical aberration correction based on a first curve can be applied to the central region, and a spherical aberration correction based on a second, different curve can be applied to the first annular region. In this case, the sagittal power at a point midway across the radial width of the first annular region can be above or below the first curve. Alternatively, the first annular region may not be corrected for spherical aberration.

[0115] Across the radial width of the central region, the sagittal power may increase between 0.01 D and 3.0 D. Across the radial width of the central region, the gradient of the sagittal power distribution may increase according to a first curve. The gradient of the sagittal power distribution across the central region increases from 0 D / mm to 3.0 D / mm with increasing distance from the optical axis. For example, the gradient may increase from 2 x 10-3 D / mm to 0.3 D / mm with increasing distance from the optical axis.

[0116] Across the radial width of the first annular region, the radial sagittal power may increase between 0.1 D and 10.0 D. The gradient of the radial sagittal power distribution across the first annular region may vary between 0.5 D / mm and 10.0 D / mm, preferably between 1.0 D / mm and 9.0 D / mm. For example, the gradient may increase from 6.0 D / mm and 6.8 D / mm. The gradient of the radial sagittal power distribution across the first annular region may vary between 1.0 D / mm and 20.0 D / mm. The gradient of the radial sagittal power distribution across the first annular region may vary between 4.0 D / mm and 12.0 D / mm.

[0117] The sagittal degree across the width of the first annular region may increase from a first value below the first curve to a second value above the first curve.

[0118] In other embodiments of the present invention, the lens may be similar to the Type A lens described above, including a spherical aberration correction across at least the central region of the lens. The central region will include a spherical aberration correction as described above and will have a sagittal power profile that increases with increasing radial distance from the optical axis of the lens.

[0119] For these embodiments, the first annular region provides a radial curvature addition power and a radial sagittal addition power. At the boundary between the central region and the first annular region, the radial curvature power may increase sharply, and the radial curvature power may be approximately constant across the radial width of the first annular region. At the boundary between the central region and the first annular region, the radial sagittal power may increase sharply. Across the radial width of the first annular region, the radial sagittal power may increase with increasing radial distance from the optical axis due to spherical aberration correction. The gradient of the radial sagittal power distribution may follow a second curve, increasing with increasing radial distance from the optical axis due to spherical aberration correction. At an outer edge of the first annular region, the radial sagittal power may be greater than the radial curvature power.

[0120] A spherical aberration correction based on a first curve is applied to the central region. A spherical aberration correction based on a second curve can be applied to the first annular region. The first curve and the second curve can be the same. Alternatively, a spherical aberration correction based on a first curve can be applied to the central region, and a spherical aberration correction based on a second, different curve can be applied to the first annular region. Alternatively, the first annular region may not be corrected for spherical aberration.

[0121] Across the radial width of the central region, the radial sagittal power may increase between 0.01 D and 3.0 D. Across the radial width of the central region, the gradient of the radial sagittal power distribution will follow a first curve, increasing with increasing radial distance from the optical axis of the lens. The gradient of the radial sagittal power distribution across the central region may increase from 0 D / mm to 3.0 D / mm with increasing distance from the optical axis. For example, the gradient may increase from 0 D / mm to 0.8 D / mm with increasing distance from the optical axis.

[0122] The radial sagittal power may be constant across the radial width of the first annular region, or may increase between 0.1 D and 3.0 D. The gradient of the radial sagittal power distribution across the radial width of the first annular region may be zero, or may follow a first curve that increases with increasing radial distance from the optical axis of the lens. The gradient of the radial sagittal power distribution across the first annular region may vary between 0 D / mm and 3.0 D / mm. For example, the gradient may increase from 0.0 D / mm to 1.9 D / mm.

[0123] In embodiments of the present invention, the lens may be similar to the C-type lens described above, including spherical aberration correction across at least the central region. The central region will include spherical aberration correction as described above and will have a sagittal power profile that increases with increasing radial distance from the optical axis of the lens. The gradient of the sagittal power profile will follow a first curve that increases with increasing radial distance from the optical axis.

[0124] The first annular region will provide an additional degree of radial curvature. The degree of radial curvature may increase sharply at the boundary between the central region and the first annular region, and the degree of radial curvature may be approximately constant across the radial width of the annular region. The radial sagittal power may increase sharply at the boundary between the central region and the first annular region. For such embodiments, the first annular region will be radially tilted relative to the central region. Across the radial width of the first annular region, the radial sagittal power will increase with increasing radial distance from the optical axis due to the radial tilt of the annular region relative to the central region. The gradient of the radial sagittal power distribution may increase with increasing radial distance from the optical axis. The gradient of the radial sagittal power distribution may increase with increasing radial distance from the optical axis following a first curve due to both spherical aberration correction and the radial tilt of the annular region relative to the central region. Alternatively, the gradient of the radial sagittal power distribution may decrease with increasing radial distance from the optical axis due to spherical aberration correction.

[0125] A spherical aberration correction based on a first curve is applied to the central region. A spherical aberration correction based on a second curve can be applied to the first annular region. Alternatively, the first annular region may not be corrected for spherical aberration. In this case, the sagittal power distribution of the first annular region may increase at a constant gradient with increasing distance from the optical axis. Alternatively, a spherical aberration correction based on a first curve can be applied to the central region, and a spherical aberration correction based on a second, different curve can be applied to the first annular region.

[0126] Across the radial width of the central region, the sagittal power may increase between 0.01 D and 3.0 D. Across the radial width of the central region, the gradient of the sagittal power distribution may increase according to a first curve. The gradient of the sagittal power distribution across the central region may increase from 0 D / mm to 3.0 D / mm as the distance from the optical axis increases. For example, the gradient may increase from 2 x 10-3 D / mm to 0.3 D / mm as the distance from the optical axis increases.

[0127] Across the radial width of the first annular region, the radial sagittal power can increase between 0.1 D and 10.0 D. The gradient of the radial sagittal power distribution across the first annular region can vary between 0.1 D / mm and 10.0 D / mm, preferably between 0.5 D / mm and 7.8 D / mm. For example, the gradient can increase from 4.8 D / mm and 5.6 D / mm. The gradient of the radial sagittal power distribution across the first annular region can vary between 1.0 D / mm and 20.0 D / mm. The gradient of the radial sagittal power distribution across the first annular region can vary between 4.0 D / mm and 12.0 D / mm.

[0128] Lenses according to embodiments of the present invention may include a second annular zone circumscribing the first annular zone. The second annular zone may provide a degree of radial curvature for hyperopia correction (i.e., the second annular zone may have the same degree of radial curvature as the central zone). The second annular zone may include spherical aberration correction to compensate for spherical aberration of the lens wearer's eye and, therefore, may have a radial sagittal power profile that increases with increasing radial distance from the optical axis. The gradient of the radial sagittal power profile across the second annular zone may increase with increasing radial distance from the optical axis. The second annular zone may have a radial width between 0.5 mm and 1.5 mm. The second annular zone may have a radial width of 0.6 mm plus or minus 0.01 mm.

[0129] A spherical aberration correction across a second annular zone may be based on the same first curve as the spherical aberration correction across the central zone.

[0130] A spherical aberration correction across a second annular zone may be based on a different curve than the spherical aberration correction across the central zone, ie the spherical aberration correction across a second annular zone may be based on a different curve than the first curve.

[0131] A lens according to an embodiment of the present invention may include a third annular zone circumscribing the second annular zone. The third annular zone may have a radial width between 0.5 mm and 1.5 mm. The third annular zone may have a radial width of 0.6 mm plus or minus 0.01 mm. The third annular zone may provide a radial curvature addition power. The third annular zone may provide a radial curvature between +2.0 D and +12.0 D greater than the hyperopia correction power of the central zone. The third annular zone may provide a radial curvature that is +2.0 D, +3.0 D, +4.0 D, +10.0 D, or +12.0 D greater than the hyperopia correction power of the central zone. The third annular zone may provide a constant radial curvature addition power. The third annular zone may provide an average radial curvature that is +2.0 D, +3.0 D, +4.0 D, +10.0 D, or +12.0 D greater than the hyperopia correction power of the central zone. The radial curvature addition degree of the third annular zone may be the same as the radial curvature addition degree of the first annular zone. The radial curvature addition degree of the third annular zone may be greater than the radial curvature addition degree of the first annular zone. The radial curvature addition degree of the third annular zone may be less than the radial curvature addition degree of the first annular zone. A spherical aberration correction may be applied to the third annular zone. Alternatively, the third annular zone may not be corrected for spherical aberration.

[0132] A third annular region may have any of the characteristics of the first annular region described above. A third annular region may have a sagittal power distribution that increases with increasing radial distance from the optical axis. The gradient of the sagittal power distribution across the annular region may increase with increasing radial distance from the optical axis.

[0133] A spherical aberration correction across a third annular zone may be based on the same second curve as the spherical aberration correction across the first annular zone, and / or the same first curve as the spherical aberration correction across the central zone.

[0134] A spherical aberration correction across a third annular zone may be based on a different curve than the spherical aberration correction across the first annular zone and / or the central zone, i.e., the spherical aberration correction across a second annular zone may be based on a fourth curve different from the first curve and / or the second curve.

[0135] Lenses according to embodiments of the present invention may include a fourth annular zone circumscribing the third annular zone. The fourth annular zone may provide a degree of radial curvature for hyperopia correction (i.e., the fourth annular zone may have the same degree of radial curvature as the central zone). The fourth annular zone may include spherical aberration correction to compensate for spherical aberration of the lens wearer's eye and, therefore, may have a radial sagittal power profile that increases with increasing radial distance from the optical axis. The gradient of the radial sagittal power profile across the fourth annular zone may increase with increasing radial distance from the optical axis. The fourth annular zone may have a radial width between 0.5 mm and 1.5 mm. The fourth annular zone may have a radial width of 0.925 mm plus or minus 0.15 mm.

[0136] A spherical aberration correction across a fourth annular zone may be based on the same first curve as the spherical aberration correction across the central zone.

[0137] A spherical aberration correction across a fourth annular zone may be based on a different curve than the spherical aberration correction across the central zone, ie the spherical aberration correction across a fourth annular zone may be based on a different curve than the first curve.

[0138] For embodiments in which the spherical aberration correction across the central zone, the first annular zone, and a second annular zone is based on the same first curve, the sagittal power at a point halfway across the width of the first annular zone and the sagittal power at a point halfway across the width of the second annular zone may lie on the first curve.

[0139] Alternatively, for embodiments in which the spherical aberration correction across the central region is based on a first curve, and the spherical aberration correction across a first annular region is based on a second curve different from the first curve, the radial sagittal power at a point halfway across the width of the central region will lie on the first curve, and the radial sagittal power at a point halfway across the width of the first annular region will lie on a second curve, which may be above or below the first curve. The second curve may have a greater gradient increase with increasing radial distance from the optical axis than the first curve.

[0140] An ophthalmic lens may include a plurality of concentric annular zones that provide a radial curvature addition power. Each concentric annular zone may have any of the characteristics of the first and second annular zones described above. The radial sagittal power across the radial width of each annular zone may increase or decrease with increasing radial distance from the optical axis. The gradient of the radial sagittal power distribution across the radial width of each annular zone may follow a first curve, increasing with increasing distance from the optical axis, to compensate for spherical aberration of a lens wearer's eye.

[0141] The radial sagittal power at a point midway across the radial width of any or all of the annular zones may lie on a first curve. The radial sagittal power at a point midway across the radial width of any or all of the annular zones may lie on a second curve different from the first curve. The second curve may provide a different spherical aberration correction. The second curve may lie above or below the first curve. Compared to the first curve, the second curve may have a greater gradient increase with increasing radial distance from the optical axis. Between any or all of the concentric annular zones providing an add power, there may be a lens region with a radial curvature power for hyperopia correction. These may be referred to as hyperopia correction power zones.

[0142] Across any radial width of the hyperopia correction power zone, the radial sagittal power may increase with increasing radial distance from the optical axis due to a spherical aberration correction. Across any radial width of the hyperopia correction power zone, the gradient of the radial sagittal power distribution may increase with increasing radial distance from the optical axis.

[0143] For embodiments in which the ophthalmic lens is a contact lens, the lens may include a hydrogel material or a silicone hydrogel material, or a combination thereof. As understood in the contact lens art, a hydrogel is a material that maintains water in equilibrium and does not contain silicone chemicals. Silicone hydrogels include hydrogels containing silicone chemicals. As described in the background of the present invention, 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). Examples of suitable lens formulations 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, 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.

[0144] According to a second aspect, the present invention provides a method for manufacturing an ophthalmic lens. The method includes providing a spherical aberration power profile, the spherical aberration power profile being a variation in the sagittal power of an eye as a function of radial distance from an optical axis of the eye. The method includes providing a target sagittal power profile for a lens wearer, the target sagittal power profile being a target variation in the sagittal power as a function of radial distance from an optical axis of the lens wearer's eye, wherein the target sagittal power profile includes a central region having a degree of radial curvature for hyperopia correction and a first annular region providing a radial curvature add power. The method includes subtracting the spherical aberration power profile from at least the central region of the target sagittal power profile to provide a corrected sagittal power profile for the ophthalmic lens. The method includes manufacturing an ophthalmic lens having the corrected sagittal power profile.

[0145] The manufactured lens may be a lens comprising any of the features according to a first aspect of the invention as described above.

[0146] As described above, the target sagittal power distribution may be a sagittal power distribution based on an A-type lens, a B-type lens, or a C-type lens.

[0147] The spherical aberration power distribution may be a measured spherical aberration distribution for a lens wearer. The spherical aberration power distribution may be a modeled spherical aberration distribution for a lens wearer. The spherical aberration power distribution may be a computer-modeled spherical aberration distribution for a lens wearer. The spherical aberration power distribution may be an average spherical aberration power distribution, wherein the average value may be obtained from a plurality of aspheric aberration power distributions measured or modeled for different lens wearers. The spherical aberration power distribution may be a measured, modeled, or average spherical aberration power distribution obtained for an eye viewing distant objects. The spherical aberration power distribution may be a measured, modeled, or average spherical aberration power distribution obtained for an eye viewing near objects. The spherical aberration power distribution may be an average spherical aberration power distribution, wherein the average value is obtained for an eye viewing near objects and an eye viewing distant objects.

[0148] The target sagittal power distribution for a lens wearer may be a modeled distribution. The steps of providing a spherical aberration power distribution, providing a target sagittal power distribution for a lens wearer, and subtracting the spherical aberration power distribution from the target sagittal power distribution to provide a corrected sagittal power distribution may be computer modeling steps.

[0149] The method may include providing a first spherical aberration power profile that plots the variation in the sagittal power of a lens wearer's eye when the eye is in a first, non-accommodated state (i.e., the state the eye is in when viewing distant objects). The method may include providing a second spherical aberration power profile that plots the variation in the sagittal power of a lens wearer's eye when the eye is in a second, accommodated state (i.e., the state the eye is in when viewing near objects). The method may include subtracting the first spherical aberration power profile from a target sagittal power profile for a central region of the lens. The method may include subtracting the second spherical aberration power profile from a target sagittal power profile for a first annular region of the lens. Thus, the corrected sagittal power profile may include a central region corrected to optimize for distance vision and a first annular region corrected to optimize for distance vision.

[0150] For embodiments of the present invention in which the ophthalmic lens is a contact lens, 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 contact lens formulation. The method may further include curing the contact lens formulation to form the lens.

[0151] For embodiments of the present invention in which the ophthalmic lens is a contact lens, the lens can be formed using a lathing process. The lens can be formed by a cast molding process, a rotational casting process, a lathing process, or a combination thereof. As understood by those skilled in the art, cast molding refers to molding a lens by placing a lens-forming material between a female mold part having a concave lens element-forming surface and a male mold part having a convex lens element-forming surface.

[0152] FIG1A shows a schematic top view of a first ophthalmic lens (a type A lens) 1 for reducing myopia progression. The lens uses a treatment zone that provides a myopic defocused image to reduce myopia progression. FIG1B shows a schematic side view of the lens 1 of FIG1A .

[0153] Lens 1 includes an optical zone 2 approximately covering the pupil and a peripheral zone 4 located above the iris. Peripheral zone 4 provides mechanical functions, including increasing the size of the lens, making it easier to handle, and providing a shaped area that improves wearer comfort. Optical zone 2 provides the optical functionality of lens 1 and includes an annular zone 3 and a central zone 5. Central zone 5 has a radial curvature degree for hyperopia correction equal to the radial sagittal power across the central zone. Annular zone 3 has a greater radial curvature degree and radial sagittal power than central zone 5.

[0154] As shown in Figures 2A and 3 , the center of curvature 8 of the central region 5 lies on a first optical axis 19, and the center of curvature of the annular region 3 lies on the first optical axis 19. The focal point 11 of the annular region 3 and the focal point 15 of the central region 5 share a common optical axis 19. The focal point 11 of the annular region 3 lies on a proximal focal plane 13 (the proximal end of the lens 1), while the focal point of the central region 5 lies on a distal focal plane 17 (the distal end of the lens 1), which is further from the rear surface of the lens 1. As shown in Figures 2B and 2C , for a distant on-axis point source, light focused by the central region 5 forms a spot 23 at the distal focal plane 17. Light focused by the central region 5 also produces an unfocused blur disk 27 at the proximal focal plane 13. Light focused by the annular region 3 forms a focused image 21 at the proximal focal plane 13. The light focused by the annular region 3 diverges after the proximal focal plane 13, and the diverging light produces an unfocused annulus 25 at the distal focal plane 17. As discussed above, the unfocused annular image 25 can cause the wearer of the lens 1 to see a "halo" around the focused distance image.

[0155] The degree of radial curvature of the annular region 3 is provided by a radius of curvature 6 of the annular region 3 which is smaller than a radius of curvature 7 of the central region 5 , as shown in FIG. 3 .

[0156] FIG4A is a plot 31 showing the variation in radial sagittal power 35 of the lens 1 shown in FIG1A and FIG1B . FIG4B is a plot 33 showing the variation in radial curvature power 37 of the lens 1 shown in FIG1A and FIG1B . FIG4A and FIG4B show the variation in power along a radial diameter of the lens 1. Across the radial width of the lens 1, the radial curvature power 37 is approximately equal to the radial sagittal power 35. The annular region 3 has a greater radial curvature power 37 than the central region 5 (i.e., the annular region has a radial add curvature power). Because the annular region 3 has an on-axis center of curvature, the radial sagittal power 35 across the annular region 3 is also greater than the radial sagittal power 35 across the central region 5 (i.e., the annular region 3 has a radial sagittal add power).

[0157] FIG5A shows a partial ray diagram of a second lens 1 (a type B lens) for reducing myopia progression. In the following figures, features identical or similar to those of the lens 1 shown in FIG1A to FIG3 are indicated using the same reference numerals.

[0158] The lens 1 of FIG5A is similar to the lens 1 shown in FIG1A and FIG1B , but FIG5A has non-coaxial optics. As shown in FIG5A and FIG5D , a central region 5 of the lens 1 has a degree of radial curvature for hyperopia correction equal to the sagittal power across the central region. The center of curvature 8 of the central region 5 lies on a first optical axis 19. An annular region 3 surrounding the central region 5 has a greater degree of radial curvature than the central region 5.

[0159] In contrast to the lens 1 of Figures 1A and 1B , this lens 1 does not produce a single image or an on-axis image at the proximal focal plane 13 that can be used to avoid the need for accommodation of near objects. For a distant object, the focused image formed at the proximal focal plane 13 is the convolution of (i) a focused image of the extended object obtained using a conventional lens with the optical power of the annular region 3 and (ii) an optical transfer function representing the optical effect of the annular region 3. At the proximal focal plane 13, for a distant on-axis point source, light rays passing through the central region 5 produce a blur disk 128 (shown in Figure 5B ), similar to the lens 1 of Figures 1A and 1B . However, light rays from a distant point source passing through the annular region 3 produce a focused annulus 122 (shown in Figure 5B ) surrounding the blur disk 128.

[0160] Light rays passing through central region 5 are focused at distal focal plane 17. Annular region 3 acts as a beam stop, resulting in a small spot size for light 124 (shown in FIG. 5C ) at distal focal plane 17. In contrast to lens 1 of FIG. 1A and FIG. 1B , a ring or "halo" effect does not appear at distal focal plane 17 or is significantly reduced.

[0161] The degree of radial curvature of the annular region 3 is provided by a radius of curvature of the annular region 3 that is smaller than the radius of curvature of the central region 5. However, in contrast to the lens 1 of Figures 1A and 1B , the curvature 10 of the annular region 3 cannot be defined by a single sphere, and the center of curvature 10 of the annular region 3 does not lie on the first optical axis 19. This is illustrated in Figure 5D . The annular region 3 is radially tilted relative to the central region 5, such that the outer edge 3' of the annular region 3 is higher relative to its inner edge 3" than in the case of the lens 1 of Figures 1A and 1B . This changes the radial sagittal power of the annular region 3 but does not change the radial curvature of the annular region 3. As shown in Figure 5D , the anterior surface of the central region 5 defines a portion of the surface of a sphere of larger radius 7. The anterior surface of the annular region 3 defines a curved annular surface having a smaller radius 6.

[0162] FIG6A is a plot 131 showing the variation in radial sagittal power 135 of the lens 1 shown in FIG5A-5D. FIG6B is a plot 133 showing the variation in radial curvature power 137 of the lens 1 shown in FIG5A and FIG5D. FIG6A and FIG6B show the variation in power along a radial diameter of the lens 1. For this lens 1, the annular region 3 is radially tilted relative to the central region 5, and therefore, the annular region 3 has a center of curvature that is not on the optical axis. The tilt of the annular region 3 relative to the central region 5 means that at the boundary between the central region 5 and the annular region 3, the radial sagittal power 135 is more negative than the radial sagittal power 135 of the central region 5. The radial sagittal power 135 increases with increasing radial distance toward the outer edge of the annular region 3. Because the annular region 3 provides an additional degree of radial curvature, the radial curvature power 137 across the annular region 3 is greater than the radial curvature power 137 across the central region 5.

[0163] FIG7A shows a partial ray diagram of a third lens (a C-type lens) 1 for reducing myopia progression. Lens 1 is similar to the lens 1 described in FIG1A and FIG1B and the lens 1 described in FIG5A and FIG5D. A central region 5 of lens 1 has a hyperopia-correcting radial curvature equal to the sagittal power across the central region. This hyperopia-correcting radial curvature is caused by a radius of curvature of the front surface of lens 1. The center of curvature of central region 5 lies on a first optical axis 19. Annular region 3 has a radial curvature greater than the base radial curvature. The radial curvature of annular region 3 is provided by a radius of curvature 6 of annular region 3, which is smaller than radius of curvature 7 of central region 5.

[0164] At a point halfway across the width of the annular region 3, the radial curvature of the annular region 3 has a value of approximately +3.5 D. Similar to the lens 1 shown in Figures 5A and 5D, the annular region 3 of lens 1 has been radially tilted relative to the central region 5, such that the center of curvature 10 of the annular region 3 is offset from the first optical axis 19. Tilting the annular region 3 relative to the central region 5 reduces the radial sagittal power at the boundary between the central region 5 and the annular region 3. At a point halfway across the width of the annular region 3, the radial sagittal power is approximately +2.25 D, which is greater than the base radial sagittal power but less than the radial curvature power.

[0165] As shown in FIG7A , at a distal focal plane 17, light passing through the annular region 3 will produce a circle of confusion 229 (shown in FIG7B ). Light from a distant on-axis point source passing through the central region 5 will form a focused image 223 (shown in FIG7B ). At a first proximal focal plane 18, light passing through the annular region 3 will produce an unfocused annulus 225 (shown in FIG7C ). At a second proximal focal plane 20, light passing through the central region 5 will produce a third blur disk 241, and light passing through the annular region 3 will produce a focused annulus 243 within the third blur disk 241, as shown in FIG7D .

[0166] FIG8A is a plot 231 showing the variation in the degree of curvature 235 across a radial diameter of the lens 1 shown in FIG7A . This plot 231 shows the average values ​​of the radial and circumferential curvatures. Across the central region 5, the degree of curvature 235 of the lens 1 is approximately constant and near zero. At the boundary between the central region 5 and the annular region 3, the degree of curvature 235 shows a sharp increase. This is due to the increase in the degree of radial curvature. The degree of circumferential curvature does not change significantly at the boundary between the central region 5 and the annular region 3, but the degree of radial curvature increases, and therefore the average degree of curvature 235 increases at the boundary.

[0167] FIG8B is a plot 233 showing the variation in sagittal power 237 across a radial diameter of the lens 1 shown in FIG7A . This plot 233 shows the average values ​​of radial and circumferential sagittal power. Across the central zone 5 of the lens 1, the sagittal power 237 is constant and has a value of 0.0 D. At the boundary between the central zone 5 and the annular zone 3, the sagittal power 237 of the annular zone 3 increases sharply due to the increase in radial sagittal power. The radial sagittal power increases in a nearly linear manner, extending radially outward across the width of the annular zone 3. In contrast to the sagittal power curve shown in FIG6A , the sagittal power 237 does not decrease at the boundary between the central zone 5 and the annular zone 3. The increase in sagittal power 237 at the boundary between the central zone 5 and the annular zone 3 will not be as great as for an A-type lens with an on-axis add-power annular zone (e.g., as described in FIG1A-4B ).

[0168] FIG9 shows a radial-sagittal power plot 333 for an ophthalmic lens 1 according to an embodiment of the present invention. This lens 1 is based on a type B lens 1 as shown in FIG5A-6B , but includes correction to compensate for spherical aberration of the eye's lens. The lens 1 has non-coaxial optics; that is, the annular region 3 of the lens 1 does not focus light from a distant on-axis point source to a point on the optical axis 19. The lens 1 includes a central region 5 that provides radial curvature correction for hyperopia, a first annular region 3 circumscribing the central region 5, a second annular region 5a circumscribing the first annular region 3, and a third annular region 3a circumscribing the second annular region 5a. The first and third annular regions 3a provide a radial curvature addition power and are radially tilted relative to the central region 5. Between the first and third annular regions 3, 3a, the second annular region 5a provides radial curvature correction for hyperopia.

[0169] The lens 1 is manufactured using a method according to an embodiment of the present invention as explained below.

[0170] Curve 338 with triangular markers shows a spherical aberration power distribution 338 for an eye. Spherical aberration power distribution 338 shows the variation in the sagittal power of the lens of an eye as a function of the radial distance from the optical axis of the eye. The sagittal power of the eye decreases along a smooth curve as the radial distance from the optical axis of the eye increases.

[0171] Curve 335 with square markers shows a target radial-sagittal power profile 335 for a lens wearer. The target radial-sagittal power profile shows the desired variation in radial-sagittal power for the lens wearer as a function of radial distance from the optical axis of the eye. In this example, target radial-sagittal power profile 335 is similar to radial-sagittal power profile 135 for Type B non-coaxial lens 1 described in Figures 5A-6B. Across a central region 5 of lens 1, target radial-sagittal power profile 335 is flat, and the radial-sagittal power matches the radial curvature power of lens 1 for hyperopia correction. At the boundary between central region 5 and first annular region 3, the radial-sagittal power decreases sharply. Across the radial width of first annular region 3, the radial-sagittal power increases linearly, and radial-sagittal power profile 335 has a constant gradient. At a point midway across the radial width of the first annular zone 3, the radial sagittal power matches that of the central zone 5. That is, the radial sagittal power at a point midway across the radial width of the first annular zone 3 matches the degree of radial curvature for hyperopia correction. The average radial sagittal add power across the first annular zone 3 is zero. At an outer edge of the first annular zone 3, the radial sagittal power decreases sharply again. Across the second annular zone 5a, the radial sagittal power is constant and equal to the degree of radial curvature for hyperopia correction. At the boundary between the annular hyperopia power zone 5a and the third annular zone 3a, the radial sagittal power decreases sharply. Across the third annular zone 3a, the radial sagittal power increases, and the radial sagittal power distribution has a constant gradient.

[0172] Curve 336 with circular markers shows a compensated radial sagittal power profile 336 resulting from subtracting the spherical aberration power profile 338 of an eye from the target radial sagittal power profile 335 of a lens wearer. In a method according to an embodiment of the present invention, the compensated radial sagittal power profile 336 is used to manufacture an ophthalmic lens 1. Across the central region 5, the radial sagittal power increases with increasing radial distance from the optical axis 19 of the lens 1. The gradient of the radial sagittal power profile 336 follows a first curve, increasing with increasing distance from the optical axis. The first curve 341 has a shape opposite to that of the spherical aberration power profile 338 and is indicated by the dashed line 341 in FIG. At the boundary between the central region 5 and the first annular region 3, the radial sagittal power decreases sharply. Across the radial width of the first annular zone 3, the radial sagittal power increases with increasing radial distance from the optical axis 19, and the gradient of the radial sagittal power distribution 336 increases with increasing radial distance from the optical axis 19. Due to the radial tilt of the first annular zone 3, the increase in radial sagittal power across the first annular zone 3 is greater than the increase in radial sagittal power across the central zone 5. At a point halfway across the radial width of the first annular zone 3 (marked "X" in FIG. 9 ), the radial sagittal power lies on the first curve 341. At the boundary between the first annular zone 3 and the second annular zone 5a, the radial sagittal power decreases sharply. Across the second annular zone 5a, the radial sagittal power increases with increasing radial distance from the optical axis 19 of the lens 1, and the gradient of the radial sagittal power distribution 336 follows the first curve, increasing with increasing distance from the optical axis 19. At the boundary between the second annular zone 5a and the third annular zone 3a, the radial sagittal power decreases again sharply. Across the radial width of the third annular zone 3a, the radial sagittal power increases with increasing radial distance from the optical axis 19, and the gradient of the radial sagittal power distribution 336 increases with increasing radial distance from the optical axis 19. At a point halfway across the radial width of the third annular zone 3a (labeled "Y" in FIG9 ), the radial sagittal power lies on the first curve. Because the third annular zone 3a is radially tilted relative to the central zone 5 and the annular hyperopia zone 5a, the increase in radial sagittal power across the third annular zone 3a is greater than the increase in radial sagittal power across the central zone 5 and the annular hyperopia zone 5a. The increase in radial sagittal power across the third annular zone 3a is greater than the increase in radial sagittal power across the first annular zone 3, and the rate of increase in radial sagittal power across the third annular zone 3a is greater than the rate of increase in radial sagittal power across the first annular zone 3. This is because the spherical aberration of the eye increases with increasing distance from the optical axis 19.Similarly, the increase in radial sagittal power across the second annular zone 5a is greater than the increase in radial sagittal power across the central zone 5, and the rate of increase in radial sagittal power across the second annular zone 5a is greater than the rate of increase in radial sagittal power across the central zone 5 because the spherical aberration of the lens wearer's eye increases with increasing distance from the optical axis 19.

[0173] FIG10 shows a radial-sagittal power plot 433 of another ophthalmic lens 1 according to an embodiment of the present invention. This lens 1 is similar to the lens 1 described in FIG9 , except that the hyperopia correction power zones of lens 1 (i.e., central zone 5 and second annular zone 5a) are corrected using a first spherical aberration power distribution 438a measured for an eye in a non-accommodated state (i.e., an eye viewing distant objects), and the treatment zones of lens 1 (i.e., first annular zone 3 and third annular zone 3a) are corrected using a second spherical aberration power distribution 438b measured for an eye in an accommodated state (i.e., an eye viewing near objects) of a lens wearer viewing near objects. Lens 1 includes a central zone 5, a first annular zone 3, a second annular zone 5a, and a third annular zone 3a. The first annular zone 3 and third annular zone 3a provide a radial curvature add power and are radially tilted relative to the central zone 5 of lens 1. Between the first annular region 3 and the third annular region 3a, there is a second annular region 5a providing a degree of radial curvature for hyperopia correction. The lens 1 has non-coaxial optics (i.e., the first annular region 3 and the third annular region 3a focus light from a distant on-axis point source to a point not on the optical axis 19 of the lens), similar to the type B lens 1 described in Figures 5A to 6B and the lens 1 of Figure 9.

[0174] Curve 438a, marked with solid circles, shows a first spherical aberration power distribution 438a for an eye in a non-accommodated state (i.e., an eye viewing distant objects). The sagittal power of the eye decreases along a smooth curve as the radial distance from the optical axis of the eye increases. Curve 438b, marked with diamonds, shows a second spherical aberration power distribution 438b for an eye in an accommodated state (i.e., an eye viewing near objects), plotting the change in the sagittal power of the eye as a function of the radial distance from the optical axis of the eye. When viewing near objects, the eye's spherical aberration is greater than when viewing distant objects, and therefore, the effect of spherical aberration on the sagittal power of the eye is greater than when viewing near objects. Therefore, the spherical aberration power distribution 438b for near objects decreases more and at a faster rate with increasing radial distance from the optical axis 19 than the spherical aberration power distribution 438a of an eye in a non-accommodated state.

[0175] Curve 436 with circular markers shows a compensated sagittal power profile that has been corrected using spherical aberration power profiles 438a and 438b. The central region 5 of lens 1 and the annular distance vision zone 5a of lens 1 have been corrected by subtracting the spherical aberration curve 438a from the target sagittal power profile 435a shown by curve 435a with square markers (which is optimized for distance vision). The first annular region 3 and the third annular region 3a of lens 1 have been corrected by subtracting the spherical aberration curve 438a from the target sagittal power profile 435b shown by curve 435b with triangular markers (which is optimized for near vision).

[0176] Across the central zone 5, the radial sagittal power increases with increasing radial distance from the optical axis 19 of the lens 1. The gradient of the radial sagittal power distribution 436 follows a first curve 441, increasing with increasing distance from the optical axis. The first curve reflects a first spherical aberration power distribution 438a. At the boundary between the central zone 5 and the first annular zone 3, the radial sagittal power decreases sharply. Across the radial width of the first annular zone 3, the radial sagittal power increases with increasing radial distance from the optical axis 19, and the gradient of the radial sagittal power distribution 436 increases with increasing radial distance from the optical axis 19. Due to the radial tilt of the first annular zone 3, the increase in radial sagittal power across the first annular zone 3 is greater than the increase in radial sagittal power across the central zone 5. At the boundary between the first annular zone 3 and the second annular zone 5a, the radial sagittal power decreases sharply. Across the annular hyperopia zone 5a, the sagittal power increases with increasing radial distance from the optical axis 19 of the lens 1, and the gradient of the sagittal power distribution 436 follows a first curve, increasing with increasing distance from the optical axis 19. This is because both the central zone 5 and the annular hyperopia zone 5a are corrected using the spherical aberration power distribution 438a of an eye in a non-accommodated state. At the boundary between the second annular zone 5a and the third annular zone 3a, the sagittal power does not decrease sharply, but the gradient of the sagittal power distribution increases sharply. The first annular zone 3 and the third annular zone 3a are both corrected using the second spherical aberration power distribution 438b of an eye in an accommodated state. Because spherical aberration is greater for an accommodated eye, the correction across the first annular zone 3 and the third annular zone 3a is greater than the correction across the central zone 5 and the first annular hyperopia zone 5a. As a result, the radial-sagittal power distribution across the third annular zone 3a is shifted upward and exhibits a greater increase with increasing radial distance from the optical axis than the radial-sagittal power distribution of the third annular zone 3a shown in FIG9 . Across the radial width of the third annular zone 3a, the radial-sagittal power increases with increasing radial distance from the optical axis 19, and the gradient of the radial-sagittal power distribution 436 increases with increasing radial distance from the optical axis 19. At a point halfway across the radial width of the first annular zone 3 (labeled "X" in FIG10 ) and at a point halfway across the radial width of the third annular zone 3a (labeled "Y" in FIG10 ), the radial-sagittal power lies on a second curve 443 reflecting the second spherical aberration power distribution 438b because the first and third annular zones 3a are corrected for spherical aberration when the eye is in an accommodated state.

[0177] In the exemplary embodiment of the present invention described above in FIG9 and FIG10, the manufactured lens is a non-coaxial lens similar to the conventional B-type lens described in FIG5A to FIG6B, with an additional spherical aberration correction. It should be understood that the spherical aberration correction described in FIG9 or the spherical aberration correction described in FIG10 can be similarly applied to lenses similar to the A-type lens described in FIG1A to FIG4B or the C-type lens described in FIG7A to FIG8B, and such lenses can include any of the areas described in paragraphs

[0127] to

[0137] .

[0178] In the exemplary embodiments of the present invention described above in FIG. 9 and FIG. 10 , the manufactured lens compensates for the spherical aberration distribution of a lens of an eye, which causes the sagittal power distribution of the lens of the eye to decrease with increasing radial distance from the optical axis at a gradient that increases with increasing radial distance from the optical axis.

[0179] FIG11 is a flow chart illustrating a method 1000 for manufacturing an ophthalmic lens according to an embodiment of the present invention. In a first step 1001, a spherical aberration power distribution for an eye is provided. The spherical aberration power distribution is the variation of the sagittal power of the eye as a function of radial distance from an optical axis of the eye. In a second step 1003, a target sagittal power distribution is provided for the eye of a lens wearer. The target sagittal power distribution is the target variation of the sagittal power as a function of radial distance from an optical axis of the lens wearer's eye. The target sagittal power distribution has a central region having a base radial curvature power and a first annular region providing a radial curvature add power. In a third step 1005, the spherical aberration power distribution is subtracted from the target sagittal power distribution to provide a compensated sagittal power distribution for the ophthalmic lens. In a fourth step 1007, an ophthalmic lens having the compensated sagittal power distribution is manufactured.

[0180] It will be appreciated by those skilled in the art that the features of these exemplary embodiments may be combined with other embodiments falling within the scope of the invention.

[0181] Although the foregoing description refers to integers or elements that have known obvious or foreseeable equivalents, such equivalents are incorporated herein as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed to encompass any such equivalents. The reader should also understand that integers or features of the present invention described as advantageous, convenient, or similar are optional and do not limit the scope of the independent claims. Furthermore, it should be understood that such optional integers or features, while beneficial in some embodiments of the present invention, may not be desirable in other embodiments and, therefore, may not be present.

[0182] 1: Ophthalmic lenses 2: Optical area 3: First annular area 3a: The third ring area 3': outer edge 3”: Inner edge 4: Surrounding area 5: Central area 5a: Second annular area / annular hyperopia area 6: Radius of curvature 7: Radius of curvature 8: Center of curvature 10:Curvature / Center of Curvature 11: Focus 13: Proximal focal plane 15: Focus 17: Far focal plane 18: First proximal focal plane 19: First optical axis 20: Second proximal focal plane 21: Focus Image 23: Light spot 25: Unfocused ring / Unfocused ring image 27: Unfocused blurry disk 31: Plotting 33: Plotting 35: Radial sagittal degree 37: Radial curvature degree 122: Focusing Ring 124: Light 128: Fuzzy disk 131: Plotting 133: Plotting 135: Radial sagittal degree / radial sagittal degree distribution 137: Radial curvature degree 223: Focus Image 225: Unfocused ring 229: Fuzzy Circle 231: Plotting 233: Plotting 235: degree of curvature 237: Sagittal degree 241: The Third Fuzzy Disk 243: Focusing Ring 333: Radial Sagittal Degree Plot 335: Curve / Target Radial Sagittal Degree Distribution 336: Curvilinear / Compensated Sagittal Degree Distribution 338: Curvilinear / spherical aberration distribution 341: First curve / dashed line 433: Radial Sagittal Degree Plot 435a: Target radial sagittal degree distribution / curve 435b: Target sagittal degree distribution / curve 436: Curvilinear / Sagittal Degree Distribution 438a: First spherical aberration degree distribution / spherical aberration curve 438b: Second spherical aberration degree distribution / curve 441: First Curve 443: Second Curve 1000:Method 1001: First Step 1003: Second step 1005: Step 3 1007: Step 4

Claims

1. An ophthalmic lens comprising an optical region, the optical region including: A central region having a curvature centered on an optical axis, the central region providing a radial curvature power for hyperopia correction, the curvature power being determined by a local curvature of the lens, and having a radial slope power distribution that increases with increasing radial distance from the optical axis, the slope power at a location being determined by dividing the slope of the wavefront after a wavefront has passed through the lens by the radial distance from the optical axis at that location, wherein the gradient of the radial slope power distribution across the central region follows a first curve that increases with increasing radial distance from the optical axis; and a first annular region circumferential to the central region, the first annular region providing an additional radial curvature power having a radial curvature additional power that is larger than that of the central region. The first annular region has a radial slope degree distribution that increases with increasing radial distance from the optical axis, wherein the gradient of the radial slope degree distribution across the first annular region follows a second curve that increases with increasing radial distance from the optical axis, and wherein the radial width of a radial slope power across the first annular region increases from a first value located below the first curve to a second value greater than the first curve.

2. The ophthalmic lens of claim 1, further comprising a second annular region circumferential to the first annular region, wherein the second annular region provides a hyperopic correction radial curvature power and has a radial slope power distribution that increases with increasing radial distance from the optical axis, wherein the gradient of the radial slope power distribution across the second annular region follows the first curve and increases with increasing radial distance from the optical axis.

3. The ophthalmic lens of claim 1 or claim 2, wherein the radial slope power decreases sharply at one boundary of the central region and the first annular region.

4. An ophthalmic lens as claimed in claim 1 or claim 2, wherein the radial slope degree lies on the first curve at a point halfway across the radial width of the first annular region.

5. The ophthalmic lens of claim 2, further comprising a third annular region surrounding the second annular region, wherein the third annular region provides an additional power of radial curvature.

6. The ophthalmic lens of claim 5, wherein the third annular region has a radial slope degree distribution that increases with increasing radial distance from the optical axis, wherein the gradient of the radial slope degree distribution across the first annular region follows a third curve that increases with increasing radial distance from the optical axis.

7. An ophthalmic lens as claimed in claim 1 or claim 2, wherein the central region provides an average hyperopic radial curvature power between +0.5 D and -15.0 D.

8. An ophthalmic lens as claimed in claim 1 or claim 2, wherein the first annular region provides a radial curvature additional power of at least +10.0 D compared to an average hyperopic correction radial curvature power.

9. An ophthalmic lens as claimed in claim 1 or claim 2, wherein the central region has a diameter between about 2.0 mm and 4.0 mm.

10. An ophthalmic lens as claimed in claim 1 or claim 2, wherein the lens is a contact lens.

11. The ophthalmic lens of claim 10, wherein the lens comprises a hydrogel material or a polysiloxane hydrogel material, or a combination thereof.

12. A method for manufacturing an ophthalmic lens, the method comprising: Provides a spherical aberration power distribution, the spherical aberration power distribution being a variation of the radial slope power of an eye based on the radial distance from one of the optical axes of the eye, wherein the slope power at a location is determined by dividing the slope of the wavefront after it has passed through an optical surface by the radial distance from the optical axis at that location; Provides a target radial slope power distribution for a lens wearer, the target radial slope power distribution being a variation of the radial slope power based on the radial distance from one of the optical axes of the lens wearer's eye, wherein the target radial slope power distribution includes a central region having a hyperopic correction radial curvature power, the curvature power being determined by a local curvature of an optical surface, and provides a first annular region having a radial curvature additional power having a radial curvature additional power larger than that of the central region; Subtracting the spherical aberration power distribution from the central region of the target radial slope power distribution to provide an ophthalmic lens with a corrected radial slope power distribution, wherein the central region has a radial slope power distribution that increases with increasing radial distance from the optical axis, wherein the gradient of the radial slope power distribution across the central region follows a first curve that increases with increasing radial distance from the optical axis; wherein the first annular region has a radial slope power distribution that increases with increasing radial distance from the optical axis, wherein the gradient of the radial slope power distribution across the first annular region follows a second curve that increases with increasing radial distance from the optical axis, and wherein a radial slope power across the radial width of the first annular region increases from a first value located below the first curve to a second value greater than the first curve; and manufacturing an ophthalmic lens having the corrected radial slope power distribution.

13. The method of claim 12, comprising: Provides a first spherical aberration power distribution plotted on the variation of radial slope power of a lens wearer's eye when the eye is in a first maladaptive state; provides a second spherical aberration power distribution plotted on the variation of radial slope power of a lens wearer's eye when the eye is in a second maladaptive state; subtracts the first spherical aberration power distribution from the central region of the target radial slope power distribution; and subtracts the second spherical aberration power distribution from the first annular region of the target radial slope power distribution.

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