An orthokeratology contact lens for a wearer's eye

Abstract

The present invention relates to an orthokeratology contact lens for a wearer's eye, wherein a back, posterior face of the lens has at least one three-dimensional structure running along a circular or an annular path about a geometric central axis of the lens, wherein the three-dimensional structure is configured to provide or to reshape the cornea with an uneven optical power spatial distribution along the circular or annular path, and is configured and arranged to, in use, modify the optics of the cornea of the wearer's eye with that uneven optical power spatial distribution, by moulding the optics on the mid-peripheral cornea of the wearer's eye in the form of a lens of negative power composed by epithelial lenticule with an unequal relative plus power ring, to reduce myopia.

Description

[0001] An orthokeratology contact lens for a wearer’s eye

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to an orthokeratology contact lens for a wearer’s eye, with at least one three-dimensional structure for reshaping the cornea with an uneven optical power spatial distribution along a circular or annular path.

[0004] BACKGROUND OF THE INVENTION

[0005] Myopia is related to diseases that may severely induce visual impairment and typically develop because the eye's axial length grows longer than the focal length of the optical components of the eye.

[0006] Myopia has a high prevalence rate in many regions of the world. Following the World Health Organization (WHO), it is the first cause of vision impairment, and it is estimated that 50% of the world's population will be affected by 2025. A significant concern with this condition is its possible progression to high myopia, as over six (6) diopters or more than 26 mm of the axial length of the eye, which dramatically affects everyday life without optical aids and is associated with an increased risk of retinal diseases, cataract, and glaucoma. Sight threatening complications that lead to loss of vision.

[0007] Optical devices are used to modify the focus of the eye to provide a clearer image at the retinal plane. However, optical correction devices such as ophthalmic or regular contact lenses do not prevent the eye's axial length from increasing, giving higher myopia rates since it is merely prosthetic or symptomatic.

[0008] Lately, many designs of contact lenses have been released with the object of slowing down eye growth in children.

[0009] Orthokeratology (Night contact lenses):

[0010] Orthokeratology, or ortho-k, is the use of specially designed and fitted to temporarily reshape the to improve vision. Ortho-k lenses are worn at night to reshape the front surface of the eye while sleep.

[0011] A conventional rigid gas permeable lens is a bi-curved lens that has a Back Optical Zone Radius (BOZR) and a peripheral curves. Orthokeratology, or Ortho-k (OK), use gas permeable lenses specially designed to temporarily reshape the cornea to improve vision. A basic standard ortho-k lens, or reverse geometry lens, has three curved portions, from centre to periphery: a BOZR, a reverse curved portion (having a curve with a radius of curvature smaller than BOZR and the corneal surface), and a peripheral curved portion. The reverse curved portion assists the corneal moulding effect. In order to improve lens centration, the lens is further modified to multicurve design. An alignment curved portion is introduced and incorporated between the reverse curved portion and the peripheral curved portion. This alignment curved portion (AC) may also be divided into two curved portions (AC1 and AC2) to form a five-zone lens.

[0012] This combination of different curved portions controls the lens sagittal height to create a moulding effect. In closed eye condition, the tear layer under the lens creates both a hydrodynamic positive force and a negative force on the cornea to change the efficacy of treatment. The positive force is exerted to flatten the central cornea, and the negative force is extracted against the mid-peripheral cornea. With these two forces, the epithelial cells are driven from centre to mid-peripheral cornea, resulting in a lens of negative power composed by epithelial lenticule to reduce the myopia. The zone of the reverse curved portions is a relief area for tissue redistribution. Modifications induced in the cornea's epithelium, resulting in an optic zone correction with a midperipheral plus power ring (PPR). The optical zone is related to the central area where the refractive error is corrected, and the PPR surrounds it due to a curvature change (shorter radius than the original cornea). Hence, the power of the mid-peripheral cornea is increased in positive (plus) power value that induces peripheral myopic defocus. Scientific significant late discovery related those subjects in the clear myopia control effect group had a much larger modulation in the Plus Power Ring over the 360° [5], In fact, it has been shown that asymmetric plus power ring produces a physiological effect on the eye, which tends to inhibit the growth of the eye, thus mitigating the tendency for the myopic eye to grow.

[0013] Stoyan (US4952045) first introduced the concept of a three-section curve corneal lens with a Base Curve, also called Central or Back Curve since it is placed on the side in contact with the eye and considered the back surface of the lens, a Reverse Curve that induces the tear reservoir zone and a peripheral curve zone. According to this idea, the radius of curvature of the Base Curve of the Central area is larger than the radius of curvature of the corneal apex of the cornea of the myopic patient. Then, the Reverse Curve is a circular curve with a curvature radius smaller than the Base Curve and the corresponding corneal region. The reverse curve and the underlying corneal anterior surface form a circular cavity or space known as the tear reservoir, where tears accumulate and accommodate the thickening of the mid-peripheral corneal epithelial cell layer. The peripheral curve area is a circular curve or series of curves that expands to the edge of the lens, is connected with the reverse curve, and is lifted outward. The peripheral curve in the original three-segment curve design forms a line in contact with the anterior surface of the cornea. A significant drawback of this design was that the lens was easy to move, and the central positioning was not good.

[0014] To enhance the central positioning of the Ortho-K contact lenses, Reim (US5963297) proposed a four-segment curve design, namely the base curve (Base Curve Zone), the Reverse Curve zone, the Alignment Curve zone, and the Surrounding Curve zone. The reverse curve region is connected to a circular curve segment in close contact with the epithelial cell layer of the cornea. The contact of this circular segment with its corneal epithelial cell layer becomes a surface contact starting from the line of contact in the three-segment curve design, thereby enhancing the central positioning function of the Ortho-K Contact Lenses. In this sense and to improve centring, in CN114740635A, M. Xinjie et al. describe a four-quadrant asymmetric orthokeratology lens with asymmetric peripheral or alignment curves for stabilization purposes.

[0015] Several studies regarding the effect of orthokeratology (OK) or special contact lenses on myopia progression have been published and have shown that it can slow myopia progression in children. OK has recently been considered the most effective optical treatment for myopia control. Although it cannot halt myopia progression completely, the inhibitory effect on axial elongation for two years is 32% to 63%, compared with single-vision spectacles and contact lenses. Special contact lenses for myopia control had obtained efficacy between 32% and 55%. It is also unclear how long the treatment should be continued to attain the maximum benefit for each patient. However, it is known that the highest efficacy is obtained in the first six months, and then it seems to loosen the effect due probably to visual cue adaptation [1], The mechanism of orthokeratology on myopia progression has not been completely elucidated. There has been much speculation about the potential mechanism, and the predominant hypothesis that orthokeratology or special contact lenses slow myopic progression is based on the "peripheral refraction theory." The theory states that orthokeratology, or contact lenses for myopia control, reduces stimuli for axial elongation via decreasing peripheral hyperopic defocus and increasing peripheral myopic defocus [2],

[0016] The mechanism to modify the retina image and induce myopic defocus is based on the changes in the called optic zone correction and the mid-peripheral plus power ring. These optical shapes may be modified by the design of the orthokeratology lens, as the present inventors have shown in their scientific research reducing the optic zone diameter [3], Surprisingly, the present inventors discovered that they could create different shapes in the cornea by modifying specific areas in the orthokeratology lens design, which led to an extraordinary treatment effect. Nevertheless, it is essential to note that the improved myopia control effect of the smaller BOZD (back optical zone diameter) ortho-k lenses occurs mainly during the first six months (which may be due to the retinal adaptation to the treatment optics), and the between-group difference in Axial Elongation was not significant afterwards in current lenses [4],

[0017] In summary, prior art orthokeratology contact lenses provide a stable, constant defocus or aberration input with a limited efficacy at long term.

[0018] CN110515218A discloses an orthokeratology contact lens including the features of the preamble of claim 1. However, the three-dimensional structure of the back, posterior or internal face of the lens disclosed in that document is configured and arranged to improve the degree of parallelism and anastomosis between the lens and the cornea, to address asymmetries and irregularities along the cornea, particularly by adapting the geometries of different parts of that three-dimensional structure to the geometries of different areas of the cornea of the wearer’s eye, for example by providing those different parts with different radii of curvature but each always consistent with the radius of curvature of the respective area of the cornea on which that part is to be applied, to achieve the same tear thickness of the tear fluid formed between each of those different parts, such as the inverted / reverse arc regions, and the corresponding corneal region, to avoid providing different corrections of myopia to those different cornea areas.

[0019] Therefore, document CN110515218A teaches away from providing an orthokeratology contact lens with a three-dimensional structure to modify the optics of the cornea of the wearer’s eye with an uneven optical power spatial distribution, as the lens there disclosed is configured and arranged to prevent that from happening, i.e., in contrast, to provide an uniform optical power spatial distribution.

[0020] It is, therefore, necessary to provide an alternative to the state of the art which covers the gaps found therein, by providing an orthokeratology contact lens which does not possess the above mentioned drawbacks.

[0021] References:

[0022] [1] Hiraoka, Takahiro M.D. Myopia Control with Orthokeratology: A Review. Eye & Contact Lens: Science & Clinical Practice 48(3): p 100-104, March 2022.

[0023] [2] Lv, Huibin M.D.; Liu, Ziyuan M.D.; Li, Jiaxi M.D.; Wang, Yuexin M.D.; Tseng, Yulin M.D.; Li, Xuemin M.D.. Long-Term Efficacy of Orthokeratology to Control Myopia Progression. Eye & Contact Lens: Science & Clinical Practice 49(9):p 399-403, September 2023. [3] Paune J, Fonts S, Rodriguez L, Queiros A. The Role of Back Optic Zone Diameter in Myopia Control with Orthokeratology Lenses. J Clin Med. 2021 Jan 18;10(2):336.

[0024] [4] Guo B, Cheung SW, Kojima R, Cho P. Variation of Orthokeratology Lens Treatment Zone (VOLTZ) Study: A 2-year randomized clinical trial. Ophthalmic Physiol. Opt. 2023 Aug 6.

[0025] [5] Wang J, Yang D, Bi H, Du B, Lin W, Gu T, Zhang B, Wei R. A New Method to Analyze the Relative Corneal Refractive Power and Its Association to Myopic Progression Control With Orthokeratology. Transl. Vis Sci Technol. 2018 Nov 30;7(6):17.

[0026] [6] Swarbrick HA. Orthokeratology review and update. Clin Exp Optom. 2006;89(3): 124-143.

[0027] [7] Chamberlain P, et al. Long-term Effect of Dual-focus Contact Lenses on Myopia Progression in Children: A 6-year Multicenter Clinical Trial. Optom Vis Sci. 2022 Mar 1 ; 99(3): 204-212.

[0028] SUMMARY OF THE INVENTION

[0029] To that end, the present invention relates, to an orthokeratology contact lens for a wearer’s eye, wherein, a back, posterior or internal face of the lens intended to face or be in contact with the wearer’s eye has at least one three-dimensional structure running along at least one circular or annular path about a geometric central axis of the lens.

[0030] In contrast to the orthokeratology contact lenses of the prior art, in the orthokeratology lens of the present invention said three-dimensional structure is configured to provide an uneven optical power spatial distribution along said at least one circular or annular path and is configured and arranged to, in use, modify the optics of the cornea of the wearer’s eye with the uneven optical power spatial distribution by moulding those optics on the mid-peripheral cornea of the wearer’s eye, in the case to reduce myopia, in the form of a lens of negative power composed by epithelial lenticule with an unequal relative plus power ring.

[0031] I.e., the uneven optical power spatial distribution is provided on the cornea of the wearer’s eye by reshaping that cornea.

[0032] For some embodiments, the three-dimensional structure is configured and arranged to achieve different tear thicknesses of the tear fluid formed between different regions of that three-dimensional structure and the corresponding corneal region onto which they are to be applied.

[0033] The first embodiment option is the different progression of power in positive relative value from the geometric centre or being divided in two sections. In that situation, the end of the central section of the bi-optical zone, for some embodiments, may have a diameter between 0 and 4 mm, with a spherical curvature or aspherical with a very low asphericity, in a span between -0.5 to 0.9 unities of eccentricity, being the total diameter of the central optical zone made up of one or several progressions of refractive power until a maximum of 10 mm of diameter. Having the optic zone or the second external portion an eccentricity between -3 to +3 or following a polynomial shape. The continuing curve will have a progression towards a smaller radius of curvature in case of an ophthalmic daily wear lens, and a larger radius of curvature in case of orthokeratology lens, or what is the same, an increase in positive power at the end of the optical zone, directly on the lens or induced over the cornea of the wearer. For some embodiments, this radial progression of refractive power will preferably be carried out differently depending on the axis, preferably representing a sinusoid or cosinusoid type oscillation once measured along the circular perimeter. For some embodiments, this oscillation will be stablished in periods between 5 to 60° degrees were the nominal power obtains its maximum and minimum. This refractive change can be applied to successive rings in which the final power will increase and decrease successively until the end of the concentric rings, their preferred number being between 1 and 6 and shaped with a width between 0.1 and 1.5 mm.

[0034] According to an embodiment, the at least one three-dimensional structure comprises a circular central region running in a circular path, wherein different crosssections of that circular central region, taken along respective radial planes including the geometric central axis of the contact lens, have different curved shapes.

[0035] For an implementation of that embodiment, the circular central region is a circular wavy central region including radial peaks and radial valleys located at respective concentric geometric circumferences about the geometric central axis of the lens, and transition radial locations between said radial peaks and radial valleys.

[0036] Therefore, for that implementation, departing from a common starting point, at the geometric central axis of the lens, for that circular central region, those crosssections that include those peaks have a curved shape with a maximum radial dimension, those that include those valleys have a curved shape with a minimum radial dimension, and the cross-sections that include those transition radial locations have radial dimension with a value between said maximum and minimum radii.

[0037] For a variant of that implementation, the end point of those cross-sections is located at the same height (i.e. at respective points of an imaginary plane perpendicular to the geometric central axis of the lens), so that the different curved shapes are only due to the different radial dimensions of the radial peaks, radial valleys, and transition radial locations of the circular central region.

[0038] For another variant of that implementation, the end point of those cross-sections of the circular central region is not located at the same height (i.e. at points of parallel imaginary planes perpendicular to the geometric central axis of the lens), so that the different curved shapes are not only due to the different radial dimensions of the radial peaks, radial valleys and transition radial locations, but also to the different height of the end points of those cross-sections of the circular central region.

[0039] For different variants of that implementation, the curved shapes of the crosssections of the circular wavy central region have the same or different curvature radii.

[0040] For an embodiment, the at least one three-dimensional structure comprises at least one annular reverse region radially extending from the circular central region of the lens and running in an annular path according to an annular reverse curved profile, wherein different cross-sections of the annular reverse curved profile, taken along respective radial planes including a geometric central axis of the contact lens, have different curved shapes and have different lengths.

[0041] For an implementation of that embodiment, the annular reverse region is an annular wavy region including radial peaks and radial valleys located at respective concentric geometric circumferences about the geometric central axis of the lens, and transition radial locations between said radial peaks and radial valleys.

[0042] For that implementation, for that annular reverse region, those cross-sections that include those peaks have a curved shape with a maximum radius and / or maximum radial dimension, those that include those valleys have a curved shape with a minimum radius and / or minimum radial dimension, and the cross-sections that include those transition radial locations have radius and / or radial dimension with a value between said maximum and minimum radii and / or radial dimension.

[0043] For a variant of that implementation, all the cross-sections of the annular reverse region depart from respective radial starting points located at the same radii (i.e. radial dimension) from the geometric central axis of the lens and at the same height (i.e. at respective points of an imaginary plane perpendicular to the geometric central axis of the lens). This would be the case of a circular non-wavy central region. For that variant, the different curved shapes are only due to the different radii (i.e. radial dimension) of the radial peaks, radial valleys, and transition radial locations of the annular reverse region.

[0044] For another variant of that implementation, not all the cross-sections of the annular reverse region depart from respective radial starting points located at the same radii (i.e. radial dimension) from the geometric central axis of the lens and / or at the same height. This would be the case of a wavy central region. For that variant, the different curved shapes are not only due to the different radii (i.e. radial dimensions) of the radial peaks, radial valleys and transition radial locations, but also to the different radii (i.e. radial dimensions) and / or different height of the radial starting points of those cross-sections of the annular reverse region.

[0045] According to a further embodiment, the at least one three-dimensional structure further comprises an annular outgoing region radially extending from the annular reverse region or from a further annular interconnection region and running in an annular path according to an annular outgoing curved profile, wherein different crosssections of that annular outgoing region, taken along respective radial planes including a geometric central axis of the contact lens, have different curved shapes and different lengths.

[0046] For an implementation of that further embodiment, the annular outgoing region is an annular wavy region including radial peaks and radial valleys located at respective concentric geometric circumferences about the geometric central axis of the lens, and transition radial locations between said radial peaks and radial valleys.

[0047] For that implementation, for that annular outgoing region, those cross-sections that include those peaks have a curved shape with a maximum radius, those that include those valleys have a curved shape with a minimum radius, and the crosssections that include those transition radial locations have radius with a value between said maximum and minimum radii.

[0048] For a variant of that implementation, all the cross-sections of the annular outgoing region depart from respective radial starting points located at the same radii from the geometric central axis of the lens and at the same height (i.e. at respective points of an imaginary plane perpendicular to the geometric central axis of the lens). For that variant, the different curved shapes are only due to the different radii of the radial peaks, radial valleys, and transition radial locations of the annular outgoing region.

[0049] For another variant of that implementation, not all the cross-sections of the annular outgoing region depart from respective radial starting points located at the same radii from the geometric central axis of the lens and / or at the same height. For that variant, the different curved shapes are not only due to the different radii of the radial peaks, radial valleys and transition radial locations, but also to the different radii and / or different height of the radial starting points of those cross-sections of the annular outgoing region. As defined in some of the embodiments, implementations and variants described above, for some embodiments of the orthokeratology contact lens of the present invention the end points of the cross-sections of the circular central region (which are also the radial starting points of the cross-sections of the annular reverse region) are not located at the same height, but at points of parallel imaginary planes perpendicular to the geometric central axis of the lens.

[0050] For a first construction embodiment of the orthokeratology lens of the present invention, the design includes an aspherical or sphero-aspherical optical zone in which, depending on the radial axis, it has a larger or smaller radius at the edge of the optical zone relative to the different meridian, resulting a different elevation at the end of the optical zone at different meridian. Changing this height will be represented once measuring circularly as a sinusoidal or cosinusoidal pattern. The annular reverse region will require adjustment to meet the normal condition in state-of-the-art lenses where the final sagittal height must match the value calculated for each individual. The diameter of the optical zone being between 3.50- and 8-mm, for some embodiments.

[0051] A second construction embodiment of the orthokeratology lens of the present invention includes a spherical, aspherical or spherical-aspherical optical zone with a different radial distance following the meridian, this distance to optical center oscillating between 4 and 7 mm, creating a kind of wave mode throughout 360°.

[0052] A third construction embodiment of the orthokeratology lens of the present invention starts from a circular optical zone, spherical, aspherical or spherical- aspherical optical zone, adjacent to which the annular inverse / reverse region will begin, which annular inverse or reverse region will have an end point located at different distances, distributed in a wave-like manner observed in a circular manner. And with a width between 0.3 and 1.5 mm.

[0053] These three exposed different construction embodiments for the circular central and annular reverse regions will be followed, for some embodiments, by a series of at least a pair of two further annular regions, wherein in every pair the cross-sections of a first of the further annular regions have a curved shape with a curvature radius larger than that of the cross-sections of the annular reverse region, and the cross-sections of a second of the further annular regions have a curved shape with a curvature radius shorter than that of the cross-sections of the first further annular region. Thus, a kind of annular cavity, groove or crevice is created, repeated two or three times with pairs of further annular regions until reaching the last, peripheral or edge annular region. It is important to note that the present invention may be incorporated into any number of different orthokeratology contact lenses formed from any number of materials.

[0054] Regarding the above mentioned different curved shapes, depending on the embodiment, they differ from each other in that they include at least one curved segment with a different radius of curvature and / or in that they have unequal aspherical curves, continuous curvature lines, splines or polynomial shapes.

[0055] With respect to the above mentioned uneven optical power spatial distribution, for an embodiment it is also an asymmetric optical power spatial distribution along the at least one circular or annular path.

[0056] For an embodiment, the uneven optical power spatial distribution follows a sinusoidal or cosinusoidal mode along the 360° of the at least one circular or annular path.

[0057] BRIEF DESCRIPTION OF THE FIGURES

[0058] In the following some preferred embodiments of the invention will be described with reference to the enclosed figures. They are provided only for illustration purposes without however limiting the scope of the invention. In accordance with common practice, the components in the figures are drawn to emphasize specific features and they are not drawn to the right scale.

[0059] Figure 1 schematically shows an embodiment of the lens of the present invention, for which the lens is an orthokeratology lens. A) lens side elevation view cross-section taken through a cutting plane represented by the 150° angled cutting plane lines A-A indicated in Fig. 1 B; B) lens bottom view; C) plot showing the sagittal distance from anterior eye surface to posterior surface of the lens or tear profile for the illustrated lens.

[0060] Figure 2 schematically shows another embodiment of the lens of the present invention, for which the lens is also an orthokeratology lens. A) lens side elevation view cross-section taken through a cutting plane represented by the 150° angled cutting plane lines B-B’ indicated in Fig. 2B; B) lens bottom view; C) plot showing the tear profile for the illustrated lens.

[0061] Figure 3 schematically shows another embodiment of the lens of the present invention, for which the lens is also an orthokeratology lens. A) lens side elevation view cross-section of the lens taken through a cutting plane represented by the 150° angled cutting plane lines C-C’ indicated in Fig. 3B; B) lens bottom view; C) plot showing the radii of curvature for the illustrated lens. Figure 4 schematically shows another embodiment of the lens of the present invention, for which the lens is also an orthokeratology lens, by means of a side elevation view cross-section of the lens taken through a cutting plane represented by 150° angled cutting plane lines similar to the cutting plane lines A-A’ of Figure 1 B but for a lens having further annular regions.

[0062] Figure 5 schematically shows another embodiment of the orthokeratology contact lens of the present invention. A) lens side elevation view cross-section of the lens taken through a cutting plane represented by the 150° angled cutting plane lines D-D’ indicated in Fig. 5B; B) lens bottom view; C) plot showing the radii of curvature for the illustrated lens.

[0063] Figure 6 is a plot representing: for an embodiment of an orthokeratology lens of the present invention, the change in heigh at the end of the optic zone in circular manner along the 360°; for an embodiment of an ophthalmic contact lens of the present invention, the oscillation of refractive power along same meridians.

[0064] DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0065] In the present section, different embodiments of the orthokeratology contact lens of the present invention are described with reference to the appended figures.

[0066] For the illustrated embodiments, the back face Lb of the orthokeratology contact lens L is intended to face the wearer’s eye is the one that has at least one three- dimensional structure that is configured and arranged to, in use, mould on the cornea of the wearer’s eye optics with an uneven optical power spatial distribution along a circular or annular path. Said optics are moulded in the case of myopia on the midperipheral cornea of the wearer’s eye in the form of a central lens of negative power composed by epithelial lenticule with an unequal relative mid peripheral plus power ring, to reduce myopia centrally and induce a myopic defocus mid peripherally.

[0067] For the embodiments of Figures 1 to 3, the orthokeratology lens L is based on a basic ortho-k lens, or reverse geometry lens, having the above mentioned three curved portions, from centre to periphery: a BOZR 1 , an annular reverse region 2, or reversed curved portion 2, and an annular peripheral region 5, or peripheral alignment curved portion 5.

[0068] Specifically, for the embodiment shown in Figures 1A, 1 B and 1 C, as shown in Figure 1 B, the three-dimensional structure comprises, as that BOZR, a circular wavy central region 1 including radial peaks and radial valleys located at respective concentric geometric circumferences about the geometric central axis of the lens L, and, as that reverse curved portion, an annular reverse region 2 radially extending from that circular wavy central region 1 and running in an annular path according to an annular reverse curved profile.

[0069] As shown in Figure 1 B, in the illustrated embodiment, the radial peaks and valleys of the circular wavy central region 1 angularly alternate along 360° every 30°, although angles, between 10 to 90°, other than 30° could also be used, for nonillustrated embodiments.

[0070] Figure 1A illustrate a cross-section that includes a left cross-section portion passing through one of said radial valleys and a right cross-section portion passing through one of said radial peaks, where those cross-sections are angularly distanced 150°

[0071] The left cross-section portion includes a cross-section 1a of the circular wavy central region 1 that has a shorter radial dimension than the one of cross-section 1b, i.e. X1<X2.

[0072] In addition, as X1+X3 = X2+X4, the radial dimension of cross-section 2a of the annular reverse region 2 is larger than the one of cross-section 2b, i.e. X3>X4.

[0073] Those radial dimensions make:

[0074] - the curved shape of cross-section 1a have a minimum radial dimension, the curved shape of cross-section 1 b have a maximum radial dimension, and the crosssections of transition radial locations have a radial dimension with a value between those minimum and maximum radii; and

[0075] - the curved shape of cross-section 2a have a minimum radius (i.e. curvature radius), the curved shape of cross-section 2b have a maximum radius (i.e. curvature radius), and the cross-sections of transition radial locations have a radius (i.e. curvature radius) with a value between those minimum and maximum radii.

[0076] In the illustrated embodiment, the curvature radii of the curved shapes of those cross-sections 1a, 1 b and those of the transition radial locations is the same. However, alternatively, the curved shape of cross-section 1a have a minimum curvature radius, the curved shape of cross-section 1b have a maximum curvature radius, and the crosssections of transition radial locations have a curvature radius with a value between those minimum and maximum radii.

[0077] Figure 1 C represents the above said by means of a plot, showing the tear profile for the lens L illustrated in Figures 1A and 1 B, particularly the distance to corneal plane of the lens (when arranged on the wearer’s user) versus the distance from the lens apex.

[0078] As shown in Figures 1A and 1C, for the illustrated embodiment, the end points of cross-sections 1a, 1b, and thus the starting points of cross-sections 2a, 2b, are located at different heights (i.e. at points of parallel imaginary planes perpendicular to the geometric central axis of the lens L) and at different radial distances, and the end points of cross-sections 2a, 2b are located at the same height and at the same radial distance, so that the different curved shapes are due to the different radii of the curved shapes of cross-sections 2a, 2b and the cross-sections of the transition radial locations, and to the different radial dimensions X1 , X2, X3, X4 and to the above mentioned different heights.

[0079] For the embodiment shown in Figures 2A, 2B and 2C, as shown in Figure 2B, the three-dimensional structure comprises a circular (non-wavy) central region 1 , and an annular wavy reverse region 2 radially extending from that circular central region 1 and running in an annular path according to an annular reverse curved profile including radial peaks and radial valleys located at respective concentric geometric circumferences about the geometric central axis of the lens L.

[0080] As shown in Figure 2B, in the illustrated embodiment, the radial peaks and valleys of the annular wavy reverse region 2 angularly alternate along 360° every 30°, although angles other than 30° could also be used, for non-illustrated embodiments.

[0081] Figure 2A illustrate a cross-section that includes a left cross-section portion passing through one of said radial valleys and a right cross-section portion passing through one of said radial peaks, where those cross-sections are angularly distanced 150°

[0082] The left cross-section portion includes a cross-section 1a of the circular central region 1 that has the same radial dimension than the one of cross-section 1 b, i.e. X5=X6.

[0083] In this case, the radial dimension of cross-section 2a of the annular wavy reverse region 2 is shorter than the one of cross-section 2b, i.e. X7<X8.

[0084] Those radial dimensions make:

[0085] - the curved shape of cross-sections 1a and 1 b be equal; and

[0086] - the curved shape of cross-section 2a have a minimum radius (i.e. curvature radius), the curved shape of cross-section 2b have a maximum radius (i.e. curvature radius), and the cross-sections of transition radial locations have a radius (i.e. curvature radius) with a value between those minimum and maximum radii.

[0087] Figure 2C represents the above said by means of a plot, showing the tear profile for the lens L illustrated in Figures 2A and 2B, particularly the distance to corneal plane of the lens (when arranged on the wearer’s user) versus the distance from the lens apex. As shown in Figures 2A and 2C, for the illustrated embodiment, the end points of cross-sections 1a, 1b, and thus the starting points of cross-sections 2a, 2b (and of cross-sections 2c of transition radial locations), are located at the same height (i.e. at respective points of an imaginary plane perpendicular to the geometric central axis of the lens L) and at the same radial distance, and the end points of cross-sections 2a, 2b are also located at the same height but at different radial distances, so that the different curved shapes of 2a, 2b, 2c are only due to the different radii of the radial valley, radial peaks, and transition radial locations of the annular wavy reverse region 2.

[0088] For the embodiment shown in Figures 3A, 3B and 3C, as shown in Figure 3B, the three-dimensional structure comprises a circular (non-wavy) central region 1 , and an annular (non-wavy) reverse region 2 radially extending from that circular central region 1 and running in an annular path according to an annular reverse curved profile.

[0089] Figure 3A illustrate a cross-section that includes a left cross-section portion and a right cross-section portion angularly distanced 150°.

[0090] The left cross-section portion includes a cross-section 1a of the circular central region 1 that has the same radial dimension than the one of cross-section 1 b, i.e. X9=X10.

[0091] In addition, as X9+X11 = X10+X12, the radial dimension of cross-section 2a is also the same as the one of cross-section 2b, i.e. X11=X12.

[0092] However, the heights of the cross-sections 2a, 2b of the annular reverse region 2 are different, i.e. their starting points are placed at different heights (i.e. at different respective points of an imaginary plane perpendicular to the geometric central axis of the lens L), particularly the height of cross-section 2a is higher than that of crosssection 2b, i.e. V1>V2.

[0093] Those heights make:

[0094] - the curved shape of cross-section 1a have a maximum radius, and the curved shape of cross-section 1b have a minimum radius; and

[0095] - the curved shape of cross-section 2a have a maximum radius, and the curved shape of cross-section 2b have a minimum radius.

[0096] Figure 3C represents the above said by means of a plot, showing the radii of curvature for the lens L illustrated in Figures 3A and 3B versus the distance from the lens apex. This section 1a and 1 b may be conformed with a single aspheric curve, a succession of multicurves linked by their tangent to conform a successive and continuous curve or a polynomial shape. As shown in Figures 3A and 3C, for the illustrated embodiment, the end points of cross-sections 1a, 1b, and thus the starting points of cross-sections 2a, 2b, are located at different heights and at the same radial distance, and the end points of crosssections 2a, 2b are located at the same height and at the same radial distance, so that the different curved shapes of 2a, 2b, 2c are only due to those different heights.

[0097] In Figure 4, a further orthokeratology lens L according to the present invention is shown, which is based on the above mentioned multicurve design, and particularly includes, between the reverse curved portion and the peripheral curved portion, an alignment curved portion divided into curved portions

[0098] Particularly, the embodiment shown in Figure 4 includes the same features as that of Figures 1A, 1 B, 1C, regarding the circular wavy central region 1 and the annular (non-wavy) reverse region 2, and a first curved portion of the alignment curved portion in the form of an annular outgoing region radially extending from the annular reverse region 2, in this case from a further annular interconnection region, and running in an annular path according to an annular outgoing curved profile.

[0099] Different cross-sections 3a, 3b of the annular outgoing region, taken along respective radial planes including a geometric central axis of the contact lens L, have different curved shapes.

[0100] In addition, for the embodiment of Figure 4, the lens L includes further curved portions of the alignment portion in the form of further annular regions radially extending from the annular outgoing region, in this case from a further annular interconnection region, and running in respective annular paths according to an annular outgoing curved profile.

[0101] Different cross-sections 4a, 4b, 5a, 5b, 6a, 6b of the further annular regions, taken along respective radial planes including a geometric central axis of the contact lens L, have different curved shapes.

[0102] As shown in Figure 4, for the embodiment there illustrated, cross-sections 3a, 3b have curved shapes with a larger curvature radii than cross-sections 2a, 2b respectively, cross-sections 4a, 4b have curved shapes with a shorter curvature radii than cross-sections 3a, 3b respectively, cross-sections 5a, 5b have curved shapes with a shorter curvature radii than cross-sections 4a, 4b respectively, and cross-sections 6a, 6b have curved shapes with a shorter curvature radii than cross-sections 5a, 5b respectively.

[0103] The different curved shapes of cross-sections 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b can be created like or similarly as explained above for cross-sections 2a, 2b (wavy annular regions, different starting or end point, etc.). The curved shapes of cross-sections 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b can be created like or similarly as explained above on frontal surface of an daily use contact lens.

[0104] The embodiment of Figures 5A, 5B and 5C is an hybrid of the embodiments of Figures 1A, 1 B, 1C and 2A, 2B, 2C.

[0105] Specifically, for the embodiment shown in those Figures 5A, 5B and 5C, as shown in Figure 5B, like for the embodiment of Figures 1A, 1 B and 1C, the three- dimensional structure comprises, as the BOZR, a circular wavy central region 1 , including radial peaks and radial valleys located at respective concentric geometric circumferences about the geometric central axis of the lens L, and, as the reverse curved portion, like for the embodiment of Figures 2A, 2B and 2C, an annular wavy reverse region 2 radially extending from that circular wavy central region 1 and running in an annular path according to an annular reverse curved profile including radial peaks and radial valleys located at respective concentric geometric circumferences about the geometric central axis of the lens L.

[0106] As shown in Figure 5B, in the illustrated embodiment, the radial peaks and valleys of both, the circular wavy central region 1 and the annular wavy reverse region 2, angularly alternate along 360° every 30°, although angles other than 30° could also be used, for non-illustrated embodiments.

[0107] Figure 5A illustrate a cross-section that includes a left cross-section portion passing through a pair of those radial valleys (one radial valley of the circular wavy central region 1 and another of the annular wavy reverse region 2) and a right crosssection portion passing through a pair of said radial peaks (one radial peak of the circular wavy central region 1 and another of the annular wavy reverse region 2), where those cross-sections are angularly distanced 150°.

[0108] The left cross-section portion includes a cross-section 1a of the circular wavy central region 1 that has a radial dimension shorter than the one of cross-section 1b, i.e. X13<X14.

[0109] In this case, the radial dimension of cross-section 2a of the annular wavy reverse region 2 is larger than the one of cross-section 2b, i.e. X15>X16.

[0110] Those radial dimensions make:

[0111] - the curved shape of cross-sections 1a and 1b have the same radius (but different radial dimensions, as stated above); and

[0112] - the curved shape of cross-section 2a and the curved shape of cross-section 2b have different radii, and the cross-sections of transition radial locations have a radius with a value between those different radii. Figure 5C represents the above said by means of a plot, showing the tear profile for the lens L illustrated in Figures 5A and 5B, particularly the distance to corneal plane of the lens (when arranged on the wearer’s user) versus the distance from the lens apex.

[0113] As shown in Figures 5A and 5C, for the illustrated embodiment, the end points of cross-sections 1a, 1b and thus the starting points of cross-sections 2a, 2b, are located at different heights (i.e. at points of parallel imaginary planes perpendicular to the geometric central axis of the lens L) and at different radial distances, and the end points of cross-sections 2a, 2b are located at the same height but at different radial distances, so that the different curved shapes are due to the different radii of the radial valley, radial peaks, and transition radial locations of the circular wavy central region 1 and of the annular wavy reverse region 2, to the above mentioned different heights and to the different radii of the curved shapes of cross-sections 2a, 2b and the crosssections of the transition radial locations.

[0114] Finally, Figure 6 shows a plot representing: for an embodiment of an orthokeratology lens of the present invention, the change in height at the end of the optic zone in circular manner along the 360°; for an embodiment of an ophthalmic contact lens of the present invention, the oscillation of refractive power along same meridians.

[0115] A person skilled in the art could introduce changes and modifications in the embodiments described without departing from the scope of the invention as it is defined in the attached claims.

Claims

Claims1.- An orthokeratology contact lens (L) for a wearer’s eye, wherein a back, posterior face (Lb) of said lens (L) intended to face or be in contact with said wearer’s eye has at least one three-dimensional structure running along at least one circular or annular path about a geometric central axis of the lens (L), characterized in that said three-dimensional structure is configured to provide an uneven optical power spatial distribution along said at least one circular or annular path and is configured and arranged to, in use, modify the optics of the cornea of the wearer’s eye with said uneven optical power spatial distribution, by moulding said optics on the mid-peripheral cornea of the wearer’s eye in the form of a lens (L) of negative power composed by epithelial lenticule with an unequal relative plus power ring, to reduce myopia,.2.- The lens (L) of any of the previous claims, wherein said at least one three- dimensional structure comprises a circular central region (1 , Lc) running in a circular path, wherein different cross-sections (1a, 1b) of said circular central region (1), taken along respective radial planes including said geometric central axis of the contact lens (L), have different curved shapes.3.- The lens (L) of claim 2, wherein said circular central region (1 , Lc) is a circular wavy central region including radial peaks and radial valleys located at respective concentric geometric circumferences about the geometric central axis of the lens (L).4.- The lens (L) of claim 3, wherein said radial peaks and valleys of said circular wavy reverse region (1) angularly alternate along 360° every 30°.5.- The lens (L) of any of claims 2 to 4, wherein in said orthokeratology contact lens (L) said at least one three-dimensional structure comprises at least one annular reverse region (2) radially extending from said circular central region (1) of the lens (L) and running in an annular path according to an annular reverse curved profile, wherein different cross-sections (2a, 2b) of said annular reverse curved profile, taken along respective radial planes including a geometric central axis of the contact lens (L), have different curved shapes.6.- The lens (L) of claim 5, wherein said at least one annular reverse region (2) is an annular wavy region including radial peaks and radial valleys located at respective concentric geometric circumferences about the geometric central axis of the lens (L).7.- The lens (L) of claim 6, wherein said radial peaks and valleys of said annular wavy region (2) angularly alternate along 360° every 30°.8.- The lens (L) of claim 5, wherein at least said at least one annular reverse region (2) is an annular non-wavy region.9.- The lens (L) of claim 5, 6, 7 or 8, wherein said at least one three-dimensional structure further comprises an annular outgoing region radially extending from said at least one annular reverse region (2) or from a further annular interconnection region and running in an annular path according to an annular outgoing curved profile, wherein different cross-sections (3a, 3b) of said annular outgoing region, taken along respective radial planes including a geometric central axis of the contact lens (L), have different curved shapes.10.- The lens according to claim 9, further comprising a further annular region radially extending from the annular outgoing region, or from a further annular interconnection region, and running in an annular path according to an annular outgoing curved profile, wherein the curved shapes of the cross-sections (2a, 2b) of the annular reverse curved profile of the at least one annular reverse region (2) have a larger curvature radii than the curved shapes of the cross-sections (3a, 3b) of the annular outgoing region, and curved shapes of the cross-sections (4a, 4b) of said further annular region have a shorter curvature radii than the cross-sections (3a, 3b) of the annular outgoing region.11.- The lens (L) of any of claims 2 to 10, wherein the end points of those crosssections of the circular central region (1) are not located at the same height, but at different heights of corresponding points of parallel imaginary planes perpendicular to the geometric central axis of the lens (L), those different heights providing those different curved shapes.12.- The lens (L) of any of claims 2 to 11 , wherein said different curved shapes differ from each other in that they include at least one curved segment with a different radius of curvature.13.- The lens (L) of claim of any of claims 2 to 12, wherein said different curved shapes differ from each other in that they have unequal aspherical curves, continuous curvature lines, splines or polynomial shapes.14.- The lens (L) of any of the previous claims, wherein said uneven optical power spatial distribution is also an asymmetric optical power spatial distribution along said at least one circular or annular path.15.- The lens (L) of any of the previous claims, wherein said uneven optical power spatial distribution follows a sinusoidal or cosinusoidal mode along the 360° of the at least one circular or annular path.

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