Myopia control contact lenses and related methods

Abstract

An ophthalmic lens (112', 200) used to prevent or slow the onset or progression of myopia comprises an optical zone (202) for focusing light from a distant point object onto a focal plane, the optical zone including a diffractive lens (206) for manipulating the longitudinal chromatic aberration characteristics of light proximate the focal plane.

Description

[Technical field]

[0001] The present disclosure relates to ophthalmic lenses used to prevent or slow the onset or progression of myopia. The present disclosure also relates to methods of making such lenses and methods of using such lenses. [Background technology]

[0002] Myopia affects a significant number of people, including children and adults. A myopic eye focuses incident light from a distant object to a location in front of the retina. As a result, the light diverges toward the retina and is out of focus when it reaches the retina. Conventional lenses for correcting myopia (e.g., eyeglass lenses and contact lenses) cause incident light from a distant object to diverge before it reaches the eye, which shifts the location of the focus onto the retina.

[0003] Decades ago, it was proposed that the progression of myopia in children and adolescents could be slowed or prevented by undercorrection, i.e., by bringing the focal point closer to the retina but not completely on the retina. However, this approach inevitably results in a decrease in distance visual acuity compared to that obtained with a lens that completely corrects myopia. Furthermore, the effectiveness of undercorrection in controlling the progression of myopia is now considered questionable. A more recent approach is to provide lenses that have both areas that provide complete correction of distance vision and areas that undercorrect, i.e., intentionally induce myopic defocus. It has been suggested that this approach can prevent or slow the onset or progression of myopia in children and adolescents while providing good distance visual acuity. The regions that provide full correction of distance vision are typically referred to as base power regions, and the regions that provide undercorrection or intentionally induce myopic defocus are typically referred to as add power regions or myopic defocus regions (where the power is more positive or less negative than the power (diopter) of the distance region).

[0004] The surface of the add power region (typically the anterior surface) has a radius of curvature that is smaller than the radius of curvature of the distance power region, thus providing a more positive or less negative optical power (diopter) to the eye. The add power region is designed to focus incoming parallel light (i.e., light from far away) into the eye in front of the retina (i.e., closer to the lens). The distance power region is designed to focus light to form an image on the retina (i.e., further from the lens).

[0005] Another type of contact lens that reduces the progression of myopia is the bifocal contact lens, available under the name MISIGHT (CooperVision, Inc.). Unlike bifocal or multifocal contact lenses that are designed to improve vision in presbyopic people, bifocal lenses are constructed with predetermined optical dimensions that provide the use of distance correction (i.e., base power) to view both distant and near objects. The treatment zone of the bifocal lens, which has an add power, provides myopic defocused images at both distant and near viewing distances.

[0006] Although these lenses have been found to be beneficial in preventing or slowing the onset or progression of myopia, the annular additional refractive power region may cause undesirable visual side effects. Light focused by the annular additional refractive power region in front of the retina diverges from the focal point to form a defocused ring on the retina. Thus, wearers of these lenses may see a ring or "halo" around the image formed on the retina, especially for small, bright objects such as street lamps or car headlights. Also, rather than using the eye's natural accommodation (i.e., the eye's natural ability to change focal length) to focus on nearby objects, the wearer may utilize the additional focal point in front of the retina resulting from the annular additional refractive power region. This, in turn, may result in the wearer unconsciously using the lens in the same manner as presbyopic corrective lenses are used, which is undesirable for young subjects.

[0007] The present disclosure provides improved lenses for use in young subjects that prevent or slow the progression of myopia. Summary of the Invention

[0008] The present disclosure provides, according to a first aspect, an ophthalmic lens for use in preventing or slowing the onset or progression of myopia, the ophthalmic lens comprising an optic zone for focusing light from a distant point object onto a focal plane, the optic zone having a diffractive lens for manipulating longitudinal chromatic aberration characteristics of the light proximate the focal plane, the ophthalmic lens may be a contact lens.

[0009] The present disclosure provides, according to a second aspect, a method of manufacturing an ophthalmic lens according to the first aspect.

[0010] The present disclosure provides, according to a third aspect, a method of reducing the progression of myopia, comprising providing an ophthalmic lens according to the first aspect to a myopic person, the ophthalmic lens being capable of accommodating to various near distances.

[0011] The present disclosure provides, according to a fourth aspect, an ophthalmic lens for use in preventing or slowing the onset or progression of myopia. The ophthalmic lens comprises an optical zone having an annular region and a central region. The central region includes a diffractive lens for manipulating the longitudinal chromatic aberration characteristics of light. The annular region has an optical power greater than a base power of the central region. Optionally, the annular region may also include a diffractive lens for manipulating the longitudinal chromatic aberration characteristics of light.

[0012] Of course, it will be understood that features described in connection with one aspect of the present disclosure may be incorporated in other aspects of the present disclosure, for example a method of the present disclosure may incorporate features described with reference to an apparatus of the present disclosure, and vice versa. [Brief description of the drawings]

[0013] [Figure 1A]FIG. 1A is a schematic plan view of a conventional contact lens used to prevent myopia.

[0014] [Figure 1B] FIG. 1B is a schematic side view of the contact lens of FIG. 1A.

[0015] [Figure 2A] FIG. 2A is a schematic ray diagram of the lens of FIG. 1A.

[0016] [Figure 2B] FIG. 2B shows a light pattern at the near focal plane of the lens of FIG. 1A formed from a distant point source.

[0017] [Figure 2C] FIG. 2C shows a light pattern at the distal focal plane of the lens of FIG. 1A formed from a distant point source.

[0018] [Figure 3A] FIG. 3A is a schematic diagram of a hyperopic or emmetropic human eye under conditions of accommodative delay (adaptation delay).

[0019] [Figure 3B] FIG. 3B is a schematic diagram of a myopic human eye.

[0020] [Figure 4] 4 is a schematic diagram of a myopic person's eye with a conventional contact lens intended to correct myopia. The myopic eye is focused on a near object and is under a state of accommodative delay.

[0021] [Figure 5A] FIG. 5A is a schematic diagram of a myopic person's eye wearing a contact lens used to prevent or slow the onset or progression of myopia, the contact lens having a diffractive optical element that causes a reversal of chromatic blur (color blur), according to one embodiment of the present disclosure.

[0022] [Figure 5B] FIG. 5B is a schematic diagram of a myopic person's eye wearing a contact lens used to prevent or slow the onset or progression of myopia, the contact lens having a diffractive optical element that causes chromatic blur cancellation, in accordance with one embodiment of the present disclosure.

[0023] [Figure 6] FIG. 6 is a graph showing calculations of the change in optical power as a function of wavelength for various diffractive lenses (diffractive optical elements) used in contact lenses according to some embodiments of the present disclosure.

[0024] [Figure 7] FIG. 7 is a graph showing refractive error as a function of wavelength for typical emmetropic, myopic and hyperopic eyes.

[0025] [Figure 8] FIG. 8 is a graph showing the calculation of refractive error as a function of wavelength when using a contact lens having a diffractive lens with a refractive power of +3.2D according to one embodiment of the present disclosure combined with a typical emmetropic eye, a myopic eye, and a hyperopic eye.

[0026] [Figure 9] FIG. 9 is a graph showing the calculation of refractive error as a function of wavelength when using a contact lens having a diffractive lens with a refractive power of +7.0D according to one embodiment of the present disclosure combined with a typical emmetropic eye, a myopic eye, and a hyperopic eye.

[0027] [Figure 10A] FIG. 10A illustrates the ring geometry for an exemplary +3.2D diffractive lens formed on a contact lens according to one embodiment of the present disclosure.

[0028] [Figure 10B] FIG. 10B illustrates the optical phase change produced by an exemplary +3.2D diffractive lens formed on a contact lens according to one embodiment of the present disclosure.

[0029] [Figure 10C] FIG. 10C illustrates a surface modulation for an exemplary +3.2D diffractive lens formed on a contact lens according to one embodiment of the present disclosure.

[0030] [Figure 10D] FIG. 10D shows the overall surface profile of a contact lens according to one embodiment of the present disclosure, including a +3.2D diffractive lens.

[0031] [Figure 11A] FIG. 11A is a schematic plan view of a contact lens for preventing myopia according to one embodiment of the present disclosure.

[0032] [Figure 11B] FIG. 11B is a schematic side view of the contact lens of FIG. 11A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] FIG. 1A shows a schematic plan view of a conventional lens used to slow the progression of myopia (e.g., myopia correction). Lens 1 comprises an optical zone 2, which generally covers the pupil, and a peripheral zone 4, which is located above the iris. The peripheral zone 4 provides mechanical functions, including increasing the size of the lens to make it easier to handle, providing ballast to prevent rotation of the lens 1, and providing a geometric region that improves comfort for the wearer of the lens 1. The optical zone 2 provides the optical functions of the lens 1, which includes an annular region 3 and a central region 5. The lens 1 has a positive base refractive power, and the radius of curvature of the anterior surface of the annular region 3 is smaller than the radius of curvature of the anterior surface of the central region 5. (This is illustrated in exaggerated schematic form in the ray diagram of FIG. 1B and the corresponding FIG. 2A.) The annular region 3 therefore has a greater refractive power than the base power of the central region 5. The focal point 11 of the annular region 3 is on the proximal focal plane 13, and the focal point 15 of the central region 5 is on the distal focal plane 17, which is further away from the rear surface of the lens 1. The focal points 11 of the annular region 3 and the focal points 15 of the central region 5 share a common optical axis 19. As shown in Figures 2B and 2C, for a point source at infinity, the light rays focused by the central region 5 form a focused image 23 at the distal focal plane 17. The light rays focused by the central region 5 also generate an unfocused blur spot 27 at the proximal focal plane 13. The light rays focused by the annular region 3 form a focused image 21 at the proximal focal plane 13. The light rays focused by the annular region 3 diverge after the proximal focal plane 13, and the diverging light rays generate an unfocused annular image 25 at the distal focal plane 17.

[0034] As previously mentioned, the out-of-focus annular image 25 can result in the wearer of the lens 1 seeing a "halo" around the focused distance image. Furthermore, the wearer could unconsciously (unknowingly) use the lens in the same manner that presbyopic corrective lenses are used, which is undesirable for younger subjects. Thus, the present disclosure provides improved lenses for use in slowing the progression of myopia.

[0035] By way of background, there is considerable evidence that accommodation is activated in conditions of hyperopic defocus to refocus the eye. When defocus at longer wavelengths is greater than defocus at shorter wavelengths, indicating that the image plane of the visually significant central part of the visible spectrum (green light) is behind the retina, hyperopic defocus results. The eye responds to this so-called chromatic blur signal / pattern by increasing its accommodation, but even in so doing it actually increases the overall image blur. This evidence indicates that chromatic blur signals / patterns are an important component of accommodation control.

[0036] FIG. 3A is a schematic diagram of a hyperopic eye 100 (or an emmetropic eye with accommodative delay). The eye 100 includes a retina 102, an accommodative lens 104, a cornea 106, an iris 107, and an optic nerve 108. Longitudinal chromatic aberration caused by natural substances present in the eye causes light of different wavelengths to be focused at different longitudinal positions relative to the retina 102, i.e., different longitudinal positions along the effective optical axis of the eye. This effect is illustrated diagrammatically in FIG. 3A by a chromatic light distribution 110. In a hyperopic eye 100 (or an emmetropic eye with accommodative delay), light of different wavelengths tends to be focused behind the retina, with blue light (represented by "B") being focused closer to the retina than green light (represented by "G"), which in turn is focused closer to the retina than red light (represented by "R"). Thus, under hyperopic defocus, the blue light portions of the image appear to be more in focus than the red light portions, as shown in Figure 3A. This chromatic blurring signal / pattern (red light being less focused than blue light) is indicative of hyperopic defocus.

[0037] FIG. 3B is a schematic diagram of a myopic eye 100′. As before, longitudinal chromatic aberration caused by natural substances present in the eye causes different wavelengths of light to be focused at different longitudinal positions relative to the retina 102. However, for the myopic eye 100′, the color distribution 110 is generally in front of the retina. Thus, blue light (represented by “B”) will be focused further from the retina than green light (represented by “G”), which will be focused further from the retina than red light (represented by “R”). Thus, under myopic defocus conditions, blue light will appear less focused than red light, which is the color blur signal / pattern indicative of myopic defocus.

[0038] FIG. 4 is a schematic diagram of a myopic eye 100' wearing a conventional contact lens 112 intended to correct myopia and allow focusing at a distance. In FIG. 4, the eye 100' is shown looking at a near target instead of a distant target. Due to accommodation delay (temporary or persistent), hyperopic defocus is present. This mimics the condition present in the hyperopic eye 100 shown in FIG. 3A. This condition therefore results in a chromatic blur signal / pattern characteristic of hyperopia / hyperopic defocus, even though the eye is in fact optically corrected for myopia using a conventional contact lens. The presence of this particular chromatic blur signal generates a so-called "growth" signal in the subject wearing the lens. This is undesirable as it may lead to an exacerbation of the subject's existing myopia.

[0039] With the above discussion in mind, FIG. 5A is a schematic diagram of a myopic eye 100' wearing a contact lens 112' of a type according to an embodiment of the present disclosure. As in FIG. 4, the myopic eye 100' is shown viewing a near target under conditions of accommodative delay. Thus, as in FIG. 4, hyperopic defocus is present (i.e., light from the target is focused behind the retinal surface). However, in contrast to the situation shown in FIG. 4, the contact lens 112' manipulates the longitudinal chromatic aberration properties of light to provide an inversion of the color blur signal / pattern compared to the hyperopic case as shown in FIG. 4.

[0040] In the embodiment shown in FIG. 5A, the color distribution 110' is manipulated (adjusted) by the contact lens 112' such that red light (represented by "R") is focused closer to the retina than green light (represented by "G"), which in turn is focused closer to the retina than blue light (represented by "B"). It should be appreciated that this results in a color blur signal / pattern indicative of myopia rather than hyperopia, since red light appears to be more focused than blue light, as in the case of the myopic eye of FIG. 3B. Thus, the presence of the color blur signal characteristic of myopia generates a so-called "stop" signal in the subject wearing the contact lens 112'. This is desirable as it slows or stops the progression of myopia in myopic subjects wearing the contact lens 112' according to an embodiment of the present disclosure.

[0041] In the embodiment shown in FIG. 5B, the color distribution 110' is manipulated by the contact lens 112' such that the red light is focused at substantially the same distance from the retina as both the green and blue light. It should be understood that this results in the cancellation of the chromatic blur signal, since the red light appears to be as focused as the blue light. This scenario creates a so-called "stop" signal for the subject wearing the contact lens 112', due to the absence of the chromatic blur signal. This slows or stops the progression of myopia in the myopic subject wearing the contact lens 112'.

[0042] A contact lens 112' used to prevent or slow the onset or progression of myopia according to an embodiment of the present disclosure comprises optical zones for converging (focusing) light from a distant point object onto a focal plane. The optical zones are shaped to form a diffractive optical element in the form of a diffractive lens. A diffractive lens manipulates the longitudinal chromatic aberration properties of light near the focal plane. A diffractive lens (sometimes referred to as a Fresnel lens or phase Fresnel lens) is a type of lens that consists of a series of zones that become finer towards the edge of the lens. A diffractive lens is typically a very thin element with a total depth equal to λ / (n-1), where λ is the operating wavelength and n is the refractive index.

[0043] In an embodiment, the diffractive lens is configured to reduce the longitudinal chromatic aberration naturally caused by the human eye, i.e., the degree of the chromatic blur signal is reduced. In another embodiment, the diffractive lens is configured to cancel the longitudinal chromatic aberration naturally caused by the human eye, i.e., the chromatic blur signal / pattern is effectively absent. In another embodiment, the diffractive lens is configured to invert the longitudinal chromatic aberration naturally caused by the human eye, i.e., the chromatic blur signal is manipulated by a contact lens to mimic that of myopic defocus, as shown diagrammatically in FIG. 5.

[0044] It should be understood that all three scenarios (reducing, canceling or reversing the longitudinal chromatic aberration naturally caused by the human eye) result in either a reduction in the growth signal or the introduction of a stop signal, all of which have the effect of slowing or preventing the progression of myopia in a subject wearing a contact lens 112' according to one embodiment of the present disclosure.

[0045] Figure 6 is a graph showing the calculation of the change in optical power as a function of wavelength for various diffractive lenses (i.e., diffractive optical elements or DOEs) with different optical powers and signs (-3D, +3D, and +7D). With reference to Figure 7, an emmetropic eye sees a blue image with myopic blur and a red image with hyperopic blur (dashed ellipse). In contrast, a myopic eye sees a good image of red and a blurred blue, and a hyperopic eye sees the opposite (i.e., blue is in focus and red is blurred).

[0046] Combining the teachings of FIG. 6 and FIG. 7, FIG. 8 is a graph showing the calculation of refractive error (refractive index error) as a function of wavelength when adding a diffractive lens of refractive power +3.2D to the eye. Line "A" corresponds to an emmetropic eye without a diffractive lens. Line "B" corresponds to an emmetropic eye with the addition of a diffractive lens of +3.2D. Line "C" corresponds to a hyperopic eye without a diffractive lens. Line "D" corresponds to a hyperopic eye with the addition of a diffractive lens of +3.2D. Line "E" corresponds to a myopic eye without a diffractive lens. Line "F" corresponds to a myopic eye with the addition of a diffractive lens of +3.2D. It should be noted that the chromatic blur signal can be cancelled by adding a diffractive lens of +3.2D. This is evident from the fact that the degree of chromatic blur (or defocus) of red and blue is approximately equal (dashed oval). Neither red nor blue light appears to be out of focus (blurred) compared to the other. This reduces the chromatic growth signal, which is the case for emmetropic eyes with accommodative delay, or for hyperopic focus eyes with reduced chromatic blur signals.

[0047] FIG. 9 is a graph showing the calculation of refractive error (refractive index error) as a function of wavelength when a diffractive lens with refractive power +7.0D is added to the eye. Line "A" corresponds to an emmetropic eye without a diffractive lens. Line "B" corresponds to an emmetropic eye with the addition of a diffractive lens with +7.0D. Line "C" corresponds to a hyperopic eye without a diffractive lens. Line "D" corresponds to a hyperopic eye with the addition of a diffractive lens with +7.0D. Line "E" corresponds to a myopic eye without a diffractive lens. Line "F" corresponds to a myopic eye with the addition of a diffractive lens with +7.0D. It should be noted that the chromatic blur signal can be inverted by adding a diffractive lens with +7.0D. In this embodiment, for a myopic eye in a state of hyperopic defocus due to accommodative delay, the use of a diffractive lens with +7.0D makes the chromatic blur signal resemble myopic defocus instead of hyperopic defocus. Thus, as previously described, a stop of eye growth signal is generated instead of a growth signal. In other words, these calculations show that by adding a higher power +7.0D diffractive lens to the eye, the color blur signals produced by hyperopia are reversed and become similar to the color blur signals typically produced by myopia, i.e., red light comes into focus and blue light defocuses (dashed ellipse).

[0048] 10A, 10B, 10C and 10D show quantitative results for one sample +3.2D diffractive lens according to one embodiment of the present disclosure. The lens has a refractive index of 1.42. FIG. 10A shows the ring geometry (radial position of each successive ring). FIG. 10B shows the optical phase change produced by the lens, which cycles between 2π radians and zero in each zone, as is typically required for a single vision lens produced by first order diffraction. FIG. 10C converts the phase to the required "mm" of surface modulation. This conversion depends on the refractive index of the lens and the surrounding medium (1.42 and 1.336 in this example). FIG. 10D shows the surface profile when the diffractive lens is added to a standard contact lens with a radius of curvature of 8.4 mm. In general, the first order diffractive power of a diffractive lens can be increased by making the ring pattern smaller or by increasing the phase step from 2π to 4π. Thus, both the size and phase step of the ring pattern can be adjusted as needed to increase the amount of longitudinal chromatic aberration caused by the diffractive lens. The diffractive lens has a central zone surrounded by a plurality of concentric ring zones. In some embodiments, the central zone has a diameter between 1.0 mm and 1.4 mm. In some embodiments, the optical phase across each zone of the diffractive lens varies over an interval of 2π radians. In some embodiments, the width of each successive ring zone is narrower than the width of the immediately preceding ring zone.

[0049] In some embodiments, the diffractive lens has negative optical power, rather than positive optical power. Thus, in use (when worn on the eye), this results in the addition of positive longitudinal chromatic aberration, rather than the reduction, cancellation, or inversion of longitudinal chromatic aberration. Such an increase in longitudinal chromatic aberration may be beneficial in certain circumstances. For example, if sufficient positive longitudinal chromatic aberration is added, the blue and red spectral components may be sufficiently blurred (smudged) to attenuate the growth signal.

[0050] It should be understood that the aspects of the present disclosure can be combined with those of prior art lenses for slowing myopia progression. For example, in the conventional lens described with reference to Figures 1 and 2, the central region 3 of the optical zone 2 can be adapted (profiled) to include a diffractive lens as disclosed herein to manipulate the longitudinal chromatic aberration characteristics of light near the focal plane. The annular region 5 of the optical zone 2 may not be substantially modified. In this way, a contact lens is obtained that generates a myopia control signal via two separate mechanisms (i.e., via a chromatic blur stop signal in addition to a myopic defocus stop signal). It should be understood that the two stop signals are generally independent of each other.

[0051] 11A and 11B show schematic diagrams of a contact lens 200 according to an embodiment of the present disclosure. The contact lens 200 comprises an optical zone 202 that generally covers the pupil and a peripheral zone 204 located above the iris. The peripheral zone 204 provides mechanical functions including increasing the size of the lens to make it easier to handle, providing ballast to optionally prevent rotation of the lens 200, and providing a geometric region that improves comfort for the wearer of the lens 200. The optical zone 202 provides the optical functions of the lens 200 and includes an annular region 203 and a central region 205. The central region 205 includes a diffractive lens 206 as disclosed herein, i.e., for manipulating the longitudinal chromatic aberration characteristics of light. The annular region 203 has an optical power greater than the base optical power of the central region 205, the focal point of the annular region 203 being on a proximal focal plane and the focal point of the central region 205 being on a distal focal plane that is further away from the posterior surface of the contact lens 200 than the proximal focal plane. It should be understood that the aspects (features) described herein with respect to diffractive lenses for manipulating longitudinal chromatic aberration also apply to the diffractive lens 206 of the contact lens 200.

[0052] As used herein, the term contact lens refers to an ophthalmic lens that can be placed on a person's eye. It will be understood that such contact lenses provide clinically acceptable on-eye movement and do not bond to the person's eye. The contact lens can be in the form of a corneal lens (e.g., a lens that rests on the cornea of ​​the eye). The contact lens can be a soft contact lens, such as a hydrogel contact lens or a silicone hydrogel contact lens.

[0053] A contact lens according to the present disclosure comprises an optic zone. The optic zone encompasses a portion of the lens having an optical function. The optic zone is configured to be positioned over the pupil of the eye in use. The optic zone is surrounded by a peripheral zone. The peripheral zone is not part of the optic zone, but is located outside the optic zone and above the iris when the lens is worn, and serves a mechanical function, for example, increasing the size of the lens to make it easier to handle, providing ballast to prevent lens rotation, and / or providing a geometric region that improves comfort for the lens wearer. The peripheral zone may extend to the edge of the contact lens.

[0054] The contact lens may comprise an elastomeric material, a silicone elastomer material, a hydrogel material, or a silicone hydrogel material, or a combination thereof. As understood in the field of contact lenses, a hydrogel is a material that holds water in equilibrium and does not contain a silicone-containing compound. A silicone hydrogel is a hydrogel that includes a silicone-containing compound. As described in the context of this disclosure, hydrogel and silicone hydrogel materials have an equilibrium water content (EWC) of at least 10% to about 90% (wt / wt). In some embodiments, hydrogel or silicone hydrogel materials have an EWC of about 30% to about 70% (wt / wt). In comparison, as described in the context of this disclosure, silicone elastomer materials have a water content of about 0% to less than 10% (wt / wt). Typically, the silicone elastomer materials used in the present method or device have a water content of 0.1% to 3% (wt / wt).Examples of suitable lens formulations (compositions) include those having the following United States Adequate 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 B, senofilcon C, senofilcon D ... senofilcon A, senofilcon B, senofilcon C, narafilcon A, narafilcon B, balafilcon A, samfilcon A, lotrafilcon A, lotrafilcon B, somofilcon A, riofilcon A, delefilcon A, verofilcon A, kalifilcon A, and the like.

[0055] Alternatively, the lens may comprise, consist essentially of, or consist of a silicone elastomer material. For example, the lens may comprise, consist essentially of, or consist of a silicone elastomer material having a Shore A hardness of 3 to 50. Shore A hardness may be determined using conventional methods (e.g., using method DIN 53505) as understood by those skilled in the art. Other silicone elastomer materials may be obtained, for example, from NuSil Technology or Dow Chemical Company.

[0056] By way of example, the lenses may include hydrogel or silicone hydrogel contact lenses having a lens diameter between 13 mm and 15 mm. The optical zone of the lens may have a diameter between 7 mm and 9 mm.

[0057] The contact lens may be a molded contact lens. The lens may be formed by a cast molding process, a spin casting process, or a lathing process, or a combination thereof. As understood by those skilled in the art, cast molding refers to a process of forming a lens by placing a lens molding material between a female mold member having a concave lens member forming surface and a male mold member having a convex lens member forming surface.

[0058] In the foregoing description, reference is made to integers or elements having known obvious or foreseeable equivalents, and such equivalents are incorporated herein as if set forth individually herein. Reference should be made to the claims to determine the true scope of the present disclosure. The claims should be construed to encompass all such equivalents. The reader will also understand that integers or features of the present disclosure described as advantageous, convenient, or the like are optional and do not limit the scope of the independent claims. Furthermore, it should be understood that such optional integers or features may be beneficial in some embodiments of the present disclosure, but may be undesirable in other embodiments, and therefore may not be present in other embodiments.

Claims

1. 1. An ophthalmic lens for use in preventing or slowing the onset or progression of myopia, comprising: An optical zone for focusing light from a distant point object onto a focal plane Equipped with The optical zone includes a diffractive lens for manipulating the longitudinal chromatic aberration characteristics of the light proximate the focal plane. An ophthalmic lens characterized by:

2. The diffractive lens is configured to reduce longitudinal chromatic aberration caused by the natural eye.

2. An ophthalmic lens according to claim 1.

3. The diffractive lens is configured to counter the longitudinal chromatic aberration caused by the natural eye.

3. An ophthalmic lens according to claim 1 or 2.

4. The diffractive lens is configured to invert the longitudinal chromatic aberration caused by the natural eye.

2. An ophthalmic lens according to claim 1.

5. The diffractive lens has a positive optical power.

5. An ophthalmic lens according to claim 1.

6. The diffractive lens has an optical power between +2.0 diopters and +8.0 diopters.

6. An ophthalmic lens according to claim 1, wherein the ophthalmic lens is a crystalline lens.

7. The diffractive lens has an optical power between +3.0 diopters and +3.4 diopters.

7. An ophthalmic lens according to claim 1, wherein the ophthalmic lens is a crystalline lens.

8. The optical power of the diffractive lens varies by at least 1.5 diopters over the wavelength range of 400 nm to 700 nm.

8. An ophthalmic lens according to claim 1, wherein the ophthalmic lens is a crystalline lens.

9. The diffractive lens has an optical power between +6.8 diopters and +7.2 diopters.

7. An ophthalmic lens according to claim 1, wherein the ophthalmic lens is a crystalline lens.

10. The optical power of the diffractive lens varies by at least 3.0 diopters over the wavelength range of 400 nm to 700 nm.

10. An ophthalmic lens according to any one of claims 1 to 6 and 9.

11. The diffractive lens has a central zone surrounded by a plurality of concentric ring-like zones.

11. An ophthalmic lens according to any one of claims 1 to 10.

12. The ophthalmic lens is a contact lens.

12. An ophthalmic lens according to any one of claims 1 to 11.

13. The central zone has a diameter between 1.0 mm and 1.4 mm.

13. An ophthalmic lens according to claim 12.

14. The optical phase across each zone of the diffractive lens varies over an interval of 2π radians.

14. An ophthalmic lens according to claim 12 or 13.

15. The width of each successive ring-shaped zone is smaller than the width of the previous ring-shaped zone.

15. An ophthalmic lens according to any one of claims 12 to 14.

16. The ophthalmic lens is a contact lens, The contact lens comprises an elastomeric material, a silicone elastomeric material, a hydrogel material, a silicone hydrogel material, or a mixture thereof.

16. An ophthalmic lens according to any one of claims 1 to 15.

17. The ophthalmic lens is a molding contact lens.

17. An ophthalmic lens according to any one of claims 1 to 16.

18. The optical zone has a base optical power between 0.5 diopters and -15.0 diopters.

18. An ophthalmic lens according to any one of claims 1 to 17.

19. the optical zone having an annular region and a central region; the central region includes the diffractive lens; The annular region has an optical power greater than the base power of the central region.

19. An ophthalmic lens according to any one of claims 1 to 18.

20. The annular region does not include a diffractive lens for manipulating the longitudinal chromatic aberration characteristics of the light.

20. An ophthalmic lens according to claim 19.

21. the focal point of the annular region is on a proximal focal plane; the focal point of the central region is on a distal focal plane; The distal focal plane is farther from the posterior surface of the contact lens than the proximal focal plane.

21. An ophthalmic lens according to claim 19 or 20.

22. The focus of the annular region and the focus of the central region share a common optical axis.

22. An ophthalmic lens according to any one of claims 19 to 21.

23. The ophthalmic lens is a contact lens, The refractive index of the contact lens material is between 1.40 and 1.

44.

23. An ophthalmic lens according to any one of claims 1 to 22.

24. A method for producing an ophthalmic lens according to any one of claims 1 to 23, comprising the steps of: Forming a lens including an optical zone for focusing light from a distant point object onto a focal plane Equipped with The optical zone includes a diffractive lens for manipulating the longitudinal chromatic aberration characteristics of the light proximate the focal plane. A method comprising:

25. 1. A method for reducing the progression of myopia, comprising: Providing an ophthalmic lens according to any one of claims 1 to 23 to a myopic person with a range of near distance accommodation. A method comprising:

26. Providing a plurality of ophthalmic lenses according to any one of claims 1 to 23 to a myopic person with various near distance accommodations. Further comprising: The diffractive lenses of the plurality of ophthalmic lenses have different optical powers, such that each ophthalmic lens produces a different longitudinal chromatic aberration manipulation.

26. The method of claim 25.

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