Manufacturing method for controlling myopia progression with a toric ophthalmic lens

Abstract

The present invention discloses a toric contact lens for controlling myopia progression and its manufacturing method. The toric contact lens can provide clear vision for the patient while having multiple annular defocus zones to form optical defocus effect. Since the different power concentric rings are connected by tangential continuity, there is no joint between the different power concentric rings, making the toric contact lens as beautiful as ordinary contact lens. The manufacturing method of the present invention uses three front mold cores, a set of rear mold cores and a flat rear mold core to manufacture a series of toric contact lenses with different powers, thereby reducing the number of mold cores and production cost. At the same time, the manufacturing method provides a semi-finished lens for the demand of high myopia and high astigmatism, which not only greatly reduces the number of mold cores, but also reduces the required inventory of lenses, thereby reducing the cost.

Description

TECHNICAL FIELD

[0001] The present application relates to ophthalmic lenses, in particular to an accommodating ophthalmic lens for controlling myopia progression and a method of manufacturing the same. BACKGROUND

[0002] Myopia is a common eye disease. Myopia is mainly due to the over-lengthening of the eyeball, which causes the focal plane of distant objects to fall in front of the retina, resulting in blurred vision of distant objects. According to a study, by 2050, there will be more than 50% of myopia population in the world. In order to find effective interventions to control the development of myopia, scholars in the relevant field have carried out a lot of research. There are three main ways now, which include 1) atropine eye drops; 2) "OK glasses" that change the curvature of the cornea; 3) off-focus glasses that blur the peripheral vision. The higher the concentration of atropine, the better the effect, but the side effects are also obvious: the pupil becomes larger, photophobia, difficulty in near vision, allergy, the higher the concentration, the more obvious the rebound of myopia, and even low-concentration atropine needs to be used under close follow-up monitoring, and the safety is difficult to guarantee. The so-called "OK glasses" are rigid contact lenses, which are worn at night, and the principle is to change the cornea to the ideal curvature by using pressure through the contact between the lens and the cornea. Patients need to wear them every night to maintain stable efficacy, and once they stop using them, they will rebound. In addition, if the hygiene of the lens is not handled properly, it will increase the risk of infection or corneal scratches. Off-focus glasses use optical technology to offset the focus of the peripheral part of the lens, making the peripheral vision blurred, which helps to inhibit the elongation of the eyeball, but due to the blurred peripheral vision, it is easy to cause tripping, and special care is needed when walking and going up and down stairs.

[0003] A recent randomized clinical study by a research team from the School of Optometry and Vision Science at the Hong Kong Polytechnic University showed that children wearing defocused soft contact lenses (DISC) had slower myopia progression than children using single-vision contact lenses over the past two years. When primary school students wore DISC lenses for 8 hours a day, myopia progression slowed down by 60%. DISC lenses are designed with alternating concentric rings of different optical powers, providing clear vision for patients while constantly receiving positive defocus signals at various visual distances, inhibiting eyeball elongation. Although DISC lenses have a positive effect on myopia control, as a contact lens, they are invasive in nature, and a large number of primary and secondary school students cannot wear soft contact lenses due to eye health problems. For example, they may have lens intolerance or use safety issues, which can limit their wearing time.

[0004] An ophthalmic lens incorporating a defocus function is very attractive and well accepted by all patients because it is essentially non-invasive, easy to wear and very safe like a traditional ophthalmic lens. At the same time, the ophthalmic lens can maximize the wearing time in order to achieve the best myopia control. However, simply transferring the concentric ring design concept of the DISC lens to an ophthalmic lens creates many problems. In particular, the presence of the junction between the concentric rings of different optical power is very visible on an ophthalmic lens and can seriously affect the aesthetics and the willingness of the patient to wear the lens. SUMMARY

[0005] An annular ophthalmic lens for controlling myopia progression and a method of manufacturing the same are disclosed. The annular ophthalmic lens provides clear vision for the patient while having multiple annular defocus zones to create an optical defocus effect. Since the annular ophthalmic lens does not have a junction between the concentric rings of different optical power, the annular ophthalmic lens is as aesthetically pleasing as a traditional ophthalmic lens. The method of manufacturing can use three front mold cores, one set of back mold cores and a flat back mold core to manufacture a range of annular ophthalmic lenses with full power, thereby reducing the number of mold cores and production costs. At the same time, the method of manufacturing provides a semi-finished lens to manufacture annular ophthalmic lenses with high myopia power and high astigmatism power. Since the market demand for high myopia power and high astigmatism power is small, the use of a separate mold core is not cost effective. The use of the semi-finished lens with post-processing not only greatly reduces the number of mold cores, but also reduces the inventory of lenses required, thereby reducing costs.

[0006] Some embodiments of the present application disclose an annular multifocal lens for controlling myopia progression, comprising a convex front surface, a concave back surface, a plurality of correction zones for imaging light on the retina, and a plurality of astigmatic zones for imaging light in front of the retina, the optical center of the front surface and the optical center of the back surface are on the same optical axis, the correction zones have a first refractive power, the astigmatic zones have a second refractive power, the second refractive power is greater than the first refractive power, the correction zones and the astigmatic zones are staggered in the annular multifocal lens. Among them, the front surface comprises a free surface composed of a plurality of first curves and a plurality of second curves, the plurality of first curves have the same radius of curvature, the plurality of second curves have the same or different radius of curvature, the radius of curvature of the first curve is greater than the radius of curvature of the second curve, the first curve and the second curve are staggered in the free surface, the correction zone is at least defined by the first curve, and the astigmatic zone is at least defined by the second curve. And wherein the first curve and the adjacent second curve are connected in a tangential continuous manner or a transition curve manner, in the tangential continuous manner, the first curve and the adjacent second curve are tangentially continuous, the end point of the first curve and the end point of the second curve coincide at the connection point, and the slope of the tangent line of the first curve and the tangent line of the second curve at the connection point is the same, and the extension line of the line connecting the center of the first curve and the center of the second curve passes through the connection point, in the transition curve manner, a transition curve is provided between the first curve and the adjacent second curve, the start point and the end point of the transition curve are connected with the end point of the first curve and the start point of the adjacent second curve respectively, at the connection point of the first curve and the transition curve, the curvature direction and size of the first curve and the transition curve are the same, at the connection point of the second curve and the transition curve, the curvature direction and size of the second curve and the transition curve are the same, and the curvature of the transition curve continuously changes.

[0007] According to some embodiments, from the center of the lens radially outward, when the diopter of the previous curve minus the diopter of the next curve is less than or equal to a threshold value, the previous curve and the next curve are connected in the tangential continuous manner, and when the diopter of the previous curve minus the diopter of the next curve is greater than the threshold value, the previous curve and the next curve are connected in the transition curve manner.

[0008] According to some embodiments, the threshold value is 3.5D.

[0009] According to some embodiments, the first curve and the second curve adjacent to each other are connected in the tangential continuous manner.

[0010] According to certain embodiments, the free-form surface is formed by a generatrix along the optical axis, the generatrix is composed of a plurality of first curves and a plurality of second curves, each first curve has a radius of curvature of the first surface, each second curve has a radius of curvature of the second surface, the first curves and the second curves are staggered in the generatrix, the first curves form the first surface by revolution, and the second curves form the second surface by revolution.

[0011] According to certain embodiments, the generatrix is a continuous smooth curve without protrusions or depressions.

[0012] According to certain embodiments, the radius of curvature of the plurality of second surfaces is constant or increases along the radial direction of the toric lens.

[0013] According to certain embodiments, the second refractive power is greater than the first refractive power by 0.5D to 5D.

[0014] According to certain embodiments, when the first refractive power is -2D to 0D, the power of the correction zone of the front surface is 401D to 600D.

[0015] According to certain embodiments, when the first refractive power is -4D to -2D, the power of the correction zone of the front surface is 201D to 400D.

[0016] According to certain embodiments, when the first refractive power is -6D to -4D, the power of the correction zone of the front surface is 50D to 200D.

[0017] According to certain embodiments, the back surface is a spherical surface, an even aspherical surface, or a biconic surface.

[0018] According to certain embodiments, the plurality of correction zones includes a correction central zone and a plurality of correction concentric rings, the correction central zone is located at the center of the toric lens, the plurality of astigmatism zones includes a plurality of astigmatism concentric rings, and the correction concentric rings and the astigmatism concentric rings are staggered.

[0019] According to certain embodiments, the diameter of the correction central zone is 5mm to 12mm, the width of the correction concentric ring is 0.5mm to 2mm, and the width of the astigmatism concentric ring is 0.5mm to 2mm.

[0020] According to certain embodiments, the plurality of astigmatism zones has 5-15 astigmatism concentric rings, and the plurality of correction zones includes 5-15 correction concentric rings.

[0021] According to certain embodiments, the center thickness of the toric lens is 1mm to 3mm, and the diameter of the toric lens is 60mm to 80mm.

[0022] Certain embodiments of the present disclosure disclose a method for manufacturing a series of toric spectacle lenses, the series of toric spectacle lenses comprising a first set of toric spectacle lenses having different degrees of myopia and astigmatism, a second set of toric spectacle lenses having different degrees of myopia and astigmatism, a third set of toric spectacle lenses having different degrees of myopia and astigmatism, and a fourth set of toric spectacle lenses having different degrees of myopia and astigmatism, the degrees of myopia of the first set of toric spectacle lenses being less than the degrees of myopia of the second set of toric spectacle lenses, the degrees of myopia of the second set of toric spectacle lenses being less than the degrees of myopia of the third set of toric spectacle lenses, the degrees of myopia of the third set of toric spectacle lenses being less than the degrees of myopia of the fourth set of toric spectacle lenses, the method comprising:

[0023] providing a first front mold core for generating a front surface having a first corrective zone curvature;

[0024] providing a second front mold core for generating a front surface having a second corrective zone curvature, wherein the first corrective zone curvature is greater than the second corrective zone curvature;

[0025] providing a third front mold core for generating a front surface having a third corrective zone curvature, wherein the second corrective zone curvature is greater than the third corrective zone curvature;

[0026] providing a set of back mold cores for generating back surfaces having different radii of curvature, the set of back mold cores comprising a plurality of back mold cores, each back mold core for generating a back surface having a corresponding radius of curvature;

[0027] providing a planar back mold core for generating a back surface that is planar;

[0028] using the first front mold core and the set of back mold cores to generate the first set of toric spectacle lenses;

[0029] using the second front mold core and the set of back mold cores to generate the second set of toric spectacle lenses;

[0030] using the third front mold core and the set of back mold cores to generate the third set of toric spectacle lenses;

[0031] using the third front mold core and the planar back mold core to generate a semi-finished lens; and machining the back surface of the semi-finished lens to generate the fourth set of toric spectacle lenses.

[0032] According to certain embodiments, the first set of toric spectacle lenses has toric spectacle lenses with first refractive powers of -2D to 0D, the second set of toric spectacle lenses has toric spectacle lenses with first refractive powers of -4D to -2D, the third set of toric spectacle lenses has toric spectacle lenses with first refractive powers of -6D to -4D, and the fourth set of toric spectacle lenses has toric spectacle lenses with first refractive powers less than -6D or degrees of astigmatism less than -2D.

[0033] According to some embodiments, the first correction zone has a curvature of 401 to 600 D, the second correction zone has a curvature of 201 to 400 D, and the third correction zone has a curvature of 50 to 200 D.

[0034] According to some embodiments, the set of back mold cores has 80 to 120 back mold cores.

[0035] According to some embodiments, the center thickness of the semi-finished lens is 2 to 20 mm. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 A structural diagram of an aspherical toric lens according to an embodiment of the present application;

[0037] Figure 2 An optical effect diagram of an aspherical toric lens according to an embodiment of the present application;

[0038] Figure 3 A schematic diagram of a generatrix of a free-form surface according to an embodiment of the present application;

[0039] Figure 4 A distribution diagram of a correction zone and a astigmatism zone according to an embodiment of the present application;

[0040] Figure 5a And Figure 5b A method of connecting different surfaces;

[0041] Figure 6 A flow chart of a method for manufacturing a series of aspherical toric lenses according to an embodiment of the present application;

[0042] Figure 7 A structural diagram of a mold according to an embodiment of the present application;

[0043] Figure 8 A schematic diagram of a front surface and a back surface according to an embodiment of the present application; and

[0044] Figure 9 A photograph of an aspherical toric lens according to an embodiment of the present application. DETAILED DESCRIPTION

[0045] The specific embodiments of the present application will be described below in conjunction with the accompanying drawings and embodiments.

[0046] Some embodiments of the present application disclose a toric contact lens for controlling myopia progression, comprising a convex front surface, a concave back surface, a plurality of correction zones for imaging light on the retina, and a plurality of astigmatic zones for imaging light in front of the retina, the optical center of the front surface and the optical center of the back surface are on the same optical axis, the correction zones have a first refractive power, the astigmatic zones have a second refractive power, the second refractive power is greater than the first refractive power, the correction zones and the astigmatic zones are staggered in the toric contact lens. Among them, the front surface comprises a free surface composed of a plurality of first curves and a plurality of second curves, the plurality of first curves have the same radius of curvature, the plurality of second curves have the same or different radius of curvature, the radius of curvature of the first curve is greater than the radius of curvature of the second curve, the first curve and the second curve are staggered in the free surface, the correction zone is at least defined by the first curve, and the astigmatic zone is at least defined by the second curve. And wherein the first curve and the adjacent second curve are connected in a tangential continuous manner or a transition curve manner, in the tangential continuous manner, the first curve and the adjacent second curve are tangentially continuous, the end point of the first curve and the end point of the second curve coincide at the connection point, and the slope of the tangent line of the first curve and the tangent line of the second curve at the connection point is the same, and the extension line of the line connecting the center of the first curve and the center of the second curve passes through the connection point, in the transition curve manner, a transition curve is provided between the first curve and the adjacent second curve, the start point and the end point of the transition curve are connected with the end point of the first curve and the start point of the adjacent second curve respectively, at the connection point of the first curve and the transition curve, the curvature direction and size of the first curve and the transition curve are the same, at the connection point of the second curve and the transition curve, the curvature direction and size of the second curve and the transition curve are the same, and the curvature of the transition curve continuously changes.

[0047] According to some embodiments, from the center of the lens radially outward, when the refractive power of the previous curve minus the refractive power of the next curve is less than or equal to a threshold value, the previous curve and the next curve are connected in the tangential continuous manner, and when the refractive power of the previous curve minus the refractive power of the next curve is greater than the threshold value, the previous curve and the next curve are connected in the transition curve manner.

[0048] According to some embodiments, the threshold value is 3.5D.

[0049] According to some embodiments, the first curve and the second curve adjacent to each other are connected in the tangential continuous manner.

[0050] According to certain embodiments, the free-form surface is formed by a generatrix along the optical axis, the generatrix is composed of a plurality of first curves and a plurality of second curves, each first curve has a radius of curvature of the first surface, each second curve has a radius of curvature of the second surface, the first curves and the second curves are staggered in the generatrix, the first curves form the first surface by revolution, and the second curves form the second surface by revolution.

[0051] According to certain embodiments, the generatrix is a continuous smooth curve without protrusions or depressions.

[0052] According to certain embodiments, the radius of curvature of the plurality of second surfaces is constant or increases along the radial direction of the toric lens.

[0053] According to certain embodiments, the second refractive power is greater than the first refractive power by 0.5D to 5D.

[0054] According to certain embodiments, when the first refractive power is -2D to 0D, the corrective zone of the front surface has a power of 401D to 600D.

[0055] According to certain embodiments, when the first refractive power is -4D to -2D, the corrective zone of the front surface has a power of 201D to 400D.

[0056] According to certain embodiments, when the first refractive power is -6D to -4D, the corrective zone of the front surface has a power of 50D to 200D.

[0057] According to certain embodiments, the back surface is a spherical surface, an even aspherical surface, or a biconic surface.

[0058] According to certain embodiments, the plurality of corrective zones includes a corrective central zone and a plurality of corrective concentric rings, the plurality of astigmatic zones includes a plurality of astigmatic concentric rings, and the corrective concentric rings and the astigmatic concentric rings are staggered.

[0059] According to certain embodiments, the diameter of the corrective central zone is 5mm to 12mm, the width of the corrective concentric rings is 0.5mm to 2mm, and the width of the astigmatic concentric rings is 0.5mm to 2mm.

[0060] According to certain embodiments, the plurality of astigmatic zones has 5-15 astigmatic concentric rings, and the plurality of corrective zones includes 5-15 corrective concentric rings.

[0061] According to certain embodiments, the central thickness of the toric lens is 1mm to 3mm, and the diameter of the toric lens is 60mm to 80mm.

[0062] Figure 1-5 shows a seamless, toric contact lens for controlling myopia progression according to an embodiment of the present application. As shown in Figures 1-2 Toric contact lens 1 comprises a convex front surface 11 and a concave back surface 12, a plurality of correction zones 101 and a plurality of astigmatism zones 102. Optical center 111 of front surface 11 and optical center 121 of back surface 12 are located on the same optical axis 10. Front surface 11 is a free-form surface 13 composed of a plurality of curves 131 and a plurality of curves 132. Curves 131 have a radius of curvature R A , curves 132 have a radius of curvature R B , R A is greater than R B , curves 131 and curves 132 are interleaved in free-form surface 13. Back surface 12 can be spherical, even aspherical or biconic. Correction zones 101 are used to provide clear vision for the patient, which images light rays on retina 201, and have a first refractive power X1 for correcting refractive errors. Correction zones 101 are defined by at least curves 131. Astigmatism zones 102 are used to provide optical defocus, which images light rays on a position 202 in front of retina 201, and have a second refractive power X2 for astigmatism. Astigmatism zones 102 are defined by at least curves 132. In this embodiment, X2 = X1 + m, m e [0.5D, 5D], X2 is preferably 3.5D. Correction zones 101 and astigmatism zones 102 are interleaved radially in toric contact lens 1.

[0063] As shown in Figure 3 , free-form surface 13 can be formed by revolving a smooth curve as a generatrix 14 along optical axis 10. Generatrix 14 is composed of a plurality of curves 141 having a radius of curvature R A and a plurality of curves 142 having a radius of curvature R B . Curves 141 and curves 142 are interleaved in generatrix 14, curves 141 revolve to form curves 131, and curves 142 revolve to form curves 132. According to some embodiments, radius of curvature R B of curves 142 is constant or increases along the radial direction of toric contact lens 1.

[0064] As shown in Figure 4 , a plurality of correction zones 101 comprises a correction central zone 101a, a plurality of correction concentric rings 101b and a correction concentric outer ring 101c. A plurality of astigmatism zones 102 comprises a plurality of astigmatism concentric rings 102a. According to this embodiment, correction central zone 101a is located at the center of toric contact lens 1, is cylindrical and has a diameter D1, which is preferably 8mm. Width W1 of correction concentric rings 101b is preferably 1mm. Diameter D2 of toric contact lens 1 is preferably 70mm. Width W2 of astigmatism concentric rings 102a is preferably 1mm. A plurality of astigmatism zones 102 preferably comprises 9 astigmatism concentric rings 102a. Central thickness of toric contact lens 1 is preferably 1.5mm.

[0065] Since the front surface 11 is a free surface 13 composed of a curved surface 131 with R A B In order to solve the problem of the joint between the concentric rings with different optical powers (i.e. different radii of curvature), the rings can be connected in a tangent-continuous manner or a transition surface manner.

[0066] In the tangent-continuous manner, the end point of the curved surface 131 of the nth ring (e.g. the corrective concentric ring 101b) coincides with the start point of the curved surface 132 of the (n+1)th ring (e.g. the astigmatic concentric ring 102a) at the joint point, and the slopes of the tangents of the curved surface 131 and the curved surface 132 at the joint point are the same, while the extension of the line connecting the centers of the curved surface 131 and the curved surface 132 passes through the joint point.

[0067] In the transition surface manner, a transition surface is provided between the nth ring and the (n+1)th ring, the start point and the end point of the transition surface are connected with the end point of the nth ring and the start point of the (n+1)th ring respectively, the curvature directions and sizes of the first curved surface and the transition surface at the joint point are the same, the curvature directions and sizes of the second curved surface and the transition surface at the joint point are the same, and the curvature continuously changes on the transition surface.

[0068] In practical applications, the tangent-continuous manner and the transition surface manner can be selected as needed to connect adjacent rings (curved surfaces). For example, the tangent-continuous manner can be selected for all, the transition surface manner can be selected for all, or the connection manner can be selected according to the difference in the refractive power of the curved surfaces of adjacent rings.

[0069] According to an embodiment, from the center of the lens radially outward, when the difference between the refractive power of the previous curved surface 131 and the refractive power of the subsequent curved surface 132 is less than or equal to a threshold value (e.g. 3.5D), the tangent-continuous manner is used to connect the rings, so that the end point of the curved surface 131 of the nth ring (e.g. the corrective concentric ring 101b) coincides with the start point of the curved surface 132 of the (n+1)th ring (e.g. the astigmatic concentric ring 102a) at the joint point, and the slopes of the tangents of the curved surface 131 and the curved surface 132 at the joint point are the same, while the extension of the line connecting the centers of the curved surface 131 and the curved surface 132 passes through the joint point. For example, Figure 5a ​As shown, the curved surface 131 and the curved surface 132 are tangent and continuous, and the endpoint 1311 of the curved surface 131 and the endpoint 1321 of the curved surface 132 coincide at the junction point 1331, and the tangent line 1312 of the curved surface 131 and the tangent line 1322 of the curved surface 132 have the same slope at the junction point 1331, and the center O A of the curved surface 131 is connected with the center O B of the curved surface 132. A B The extension line 1341 of the curved surface 134 passes through the junction point 1331, thereby solving the joint problem.

[0070] From the center of the lens, when the refractive power of the previous curved surface 131 is less than the refractive power of the next curved surface 132 by more than a threshold value (for example, 3.5D), the rings are connected in a curvature-continuous manner, and there is a transition curved surface 133 between the first curved surface 131 and the second curved surface 132. Figure 5b As shown, the endpoint 1311 of the first curved surface 131 and the starting point of the transition curved surface 133 coincide, and the curvatures and directions of the two are the same at this point; similarly, the starting point 1321 of the second curved surface 132 and the endpoint 1332 of the transition curved surface coincide, and the curvatures and directions of the two are the same at this point. On the transition curved surface 133, the curvature continuously changes from R A to R B .

[0071] Further towards manufacturing, the present application provides a production method for forming different correction power lenses by cooperating front and rear molds, which greatly reduces the number of mold cores and thus reduces production costs.

[0072] Some embodiments of the present application disclose a method for manufacturing a series of said toric lenses, said series of toric lenses including a first set of toric lenses having different myopia and astigmatism, a second set of toric lenses having different myopia and astigmatism, a third set of toric lenses having different myopia and astigmatism, and a fourth set of toric lenses having different myopia and astigmatism, the myopia of the first set of toric lenses being less than the myopia of the second set of toric lenses, the myopia of the second set of toric lenses being less than the myopia of the third set of toric lenses, and the myopia of the third set of toric lenses being less than the myopia of the fourth set of toric lenses, the method comprising:

[0073] providing a first front mold core for generating a front surface having a first correction zone curvature;

[0074] providing a second front mold core for generating a front surface having a second correction zone curvature, wherein the first correction zone curvature is greater than the second correction zone curvature; ​

[0075] a third front mold core for generating a front surface having a third corrective zone curvature, wherein the second corrective zone curvature is greater than the third corrective zone curvature;

[0076] a set of back mold cores for generating back surfaces having different radii of curvature, comprising a plurality of back mold cores, each back mold core for generating a back surface having a corresponding radius of curvature;

[0077] a planar back mold core for generating a back surface that is planar;

[0078] using the first front mold core and the set of back mold cores to generate the first set of toric lenses;

[0079] using the second front mold core and the set of back mold cores to generate the second set of toric lenses;

[0080] using the third front mold core and the set of back mold cores to generate the third set of toric lenses;

[0081] using the third front mold core and the planar back mold core to generate a semi-finished lens; and machining a back surface of the semi-finished lens to generate the fourth set of toric lenses.

[0082] According to certain embodiments, the first set of toric lenses has a first power of -2D to 0D, the second set of toric lenses has a first power of -4D to -2D, the third set of toric lenses has a first power of -6D to -4D, and the fourth set of toric lenses has a first power of less than -6D or a cylinder less than -2D.

[0083] According to certain embodiments, the first corrective zone curvature is 401D to 600D, the second corrective zone curvature is 201D to 400D, and the third corrective zone curvature is 50D to 200D.

[0084] According to certain embodiments, the set of back mold cores has 80 to 120 back mold cores.

[0085] According to certain embodiments, the semi-finished lens has a center thickness of 2mm to 20mm.

[0086] Figure 6This is a flowchart of a method for manufacturing a series of annular lenses according to an embodiment of the present invention. The series of annular lenses includes multiple sets of annular lenses with different myopia and astigmatism powers. When the myopia is greater than -6D and the astigmatism is greater than -2D, according to step S61, a first front mold core is provided for generating a first set of annular lenses with myopia ranging from 0 to -2D, a second front mold core is provided for generating a second set of annular lenses with myopia ranging from -2D to -4D, a third front mold core is provided for generating a third set of annular lenses with myopia ranging from -4D to -6D, and a set of rear mold cores is provided for generating rear surfaces with different radii of curvature. The first front mold core is used to generate a front surface with a first correction zone curvature, the second front mold core is used to generate a front surface with a second correction zone curvature, and the third front mold core is used to generate a front surface with a third correction zone curvature. The first correction zone curvature is greater than the second correction zone curvature, and the second correction zone curvature is greater than the third correction zone curvature. The set of rear mold cores includes multiple rear mold cores, each of which is used to generate a rear surface with a corresponding radius of curvature.

[0087] According to step S62, the first front mold core and the set of rear mold cores are used to generate the first set of annular lenses, the second front mold core and the set of rear mold cores are used to generate the second set of annular lenses, and the third front mold core and the set of rear mold cores are used to generate the third set of annular lenses.

[0088] When the myopia is less than -6D and the astigmatism is less than -2D, according to step S63, a planar back mold core is provided for generating a fourth set of annular lenses with myopia less than -6D and astigmatism less than -2D, which is used to generate a planar back surface. A semi-finished lens is generated using a third front mold core and a planar back mold core to produce a front surface with a third correction zone curvature and a planar back surface, and the back surface of the semi-finished lens is processed to generate the fourth set of annular lenses. The annular lenses in the first, second, third, and fourth sets of annular lenses do not overlap in myopia and astigmatism.

[0089] Figure 7 This is a structural diagram of a mold 70 according to an embodiment of the present invention. The mold 70 includes a front mold core 71 and a rear mold core 72. In this embodiment, as... Figure 8 As shown, when the first refractive power X1 of the annular lens 1 ∈ [-2D, 0D], the curvature of the correction zone of the anterior surface is preferably 500 degrees, and all myopia and astigmatism are determined by the corresponding posterior surface 12 (R C1 R C2 R C3 ...) complete. In this embodiment, the curvature of the correction zone can be calculated using the following empirical formula: Curvature of correction zone = (0.532 / R) A )x100,R Ain meters, but can also be calculated by other relevant formulas in the art. When X1 e [-4D, -2D], the correction zone power is preferably 300 curves, and all myopic and astigmatic powers are also achieved by the cooperating back surface 12 (R C1 , R C2 , R C3 ,...). When X1 e [-6D, -4D], the correction zone power is preferably 100 curves, and all myopic and astigmatic powers are also achieved by the cooperating back surface 12 (R C1 , R C2 , R C3 ,...). The entire set of molds for the series of lenses includes three front mold cores 61 for generating three different free-form front surfaces 11, and a set of back mold cores 62 for generating back surfaces 12, which cooperate to produce most of the series. Since the entire set of molds does not require a separate set of cores for each power, this method greatly reduces the number of front and back surface cores, and reduces production costs.

[0090] According to some embodiments, a front surface with a correction zone power of 500 curves, in cooperation with a back surface with a radius of 104.5819, forms a lens with a correction zone of plano, and in cooperation with a back surface with a radius of 82.6233, forms a myopic lens with a correction zone of -1.5D. When the front surface has a correction zone power of 300 curves, in cooperation with a back surface with a radius of 104.5819, forms a myopic lens with a correction zone of -2.25D, and in cooperation with a back surface with a radius of 82.6233, forms a myopic lens with a correction zone of -3.75D; and similarly, when the front surface has a correction zone power of 100 curves, in cooperation with a back surface with a radius of 104.5819, forms a myopic lens with a correction zone of -4.5D, and in cooperation with a back surface with a radius of 82.6233, forms a myopic lens with a correction zone of -6D.

[0091] When a myopic power <-6D or an astigmatic power <-2D is required, a 100 curve front mold is used, and a flat back mold is used, with a central thickness of preferably 8 mm, to produce a semi-finished lens with a front surface having a correction zone power of 100 curves and a flat back surface, which is then further processed to produce a toric lens with a myopic power <-6D or an astigmatic power <-2D. This is because such lenses are less in demand, and it is not cost-effective to produce them using molds. The semi-finished approach reduces the number of cores and inventory, thereby reducing costs.

[0092] Figure 9The actual photo of the toric lens according to the embodiment of the present application can clearly show that the lens surface has no any joint. The projection of the lens under the light can show that the correction zone and the astigmatism zone have obviously different optical powers, which fully verifies the correctness and feasibility of the present application.

[0093] Compared with the prior art, the present application has the following obvious advantages.

[0094] 1. The present application provides a manufacturing-oriented seamless toric lens design technology for controlling myopia deepening and a different optical power concentric ring tangent continuous design of the front surface, which has the same appearance as ordinary lenses without any joints and has an aesthetic appearance.

[0095] 2. The correction zone and the astigmatism zone are staggered, which reduces the peripheral visual peeling caused by optical defocus.

[0096] 3. The manufacturing-oriented method uses three front mold cores, a set of rear mold cores and a flat rear mold core to manufacture a series of lenses with complete degrees, which greatly reduces the number of mold cores and production costs.

[0097] 4. The optimized refractive power distribution not only provides the patient with a clear field of view, but also maximizes the patient's acceptance of positive optical defocus signals, inhibits eyeball elongation and improves vision.

[0098] Although the specific embodiments of the present application are described above, those skilled in the art should understand that this is only an illustration, and some changes and modifications can be made to these embodiments without departing from the principles and essence of the present application, therefore, the protection scope of the present application is defined by the appended claims.

Claims

1. A method for manufacturing a series of annular lenses, each of the annular lenses comprising a convex front surface, a concave rear surface, a plurality of corrective zones for imaging light onto the retina, and a plurality of astigmatic zones for imaging light in front of the retina, the optical centers of the front surface and the rear surface being located on the same optical axis, the corrective zones having a first refractive power, the astigmatic zones having a second refractive power greater than the first refractive power, the corrective zones and the astigmatic zones being alternately arranged in the annular lens, the front surface comprising a freeform surface composed of a plurality of first surfaces and a plurality of second surfaces, the plurality of first surfaces having the same radius of curvature, the plurality of second surfaces having the same or different radii of curvature, the radius of curvature of the first surfaces being greater than the radius of curvature of the second surfaces, the first surfaces and the second surfaces being alternately connected in the freeform surface, the corrective zones being defined at least by the first surfaces, the astigmatic zones being defined at least by the second surfaces, and the... The first curved surface and the adjacent second curved surface are connected in a tangential, continuous manner or as a transitional surface. In the transitional surface manner, a transitional surface is provided between the first curved surface and the adjacent second curved surface. The start and end points of the transitional surface are connected to the end point of the first curved surface and the start point of the adjacent second curved surface, respectively. At the connection point of the first curved surface and the transitional surface, the curvature direction and magnitude of the first curved surface and the transitional surface are the same. At the connection point of the second curved surface and the transitional surface, the curvature direction and magnitude of the second curved surface and the transitional surface are the same. The curvature on the transitional surface changes continuously radially outward from the center of each annular lens. When the difference between the refractive power of the preceding surface and the refractive power of the following surface is less than or equal to a threshold, the preceding and following curved surfaces are connected in a tangential, continuous manner. When the difference between the refractive power of the preceding surface and the refractive power of the following surface is greater than the threshold, the preceding and following curved surfaces are connected as a transitional surface. The series of ring-focus lenses includes a first set of ring-focus lenses with different myopia and astigmatism powers, a second set of ring-focus lenses with different myopia and astigmatism powers, a third set of ring-focus lenses with different myopia and astigmatism powers, and a fourth set of ring-focus lenses with different myopia and astigmatism powers. The myopia power of the first set of ring-focus lenses is less than that of the second set of ring-focus lenses, the myopia power of the second set of ring-focus lenses is less than that of the third set of ring-focus lenses, and the myopia power of the third set of ring-focus lenses is less than that of the fourth set of ring-focus lenses. The method includes: A first front mold core is provided for generating the front surface of the protrusion having a first correction zone curvature; A second front mold core is provided for generating the front surface of the protrusion having a second correction zone curvature, wherein the first correction zone curvature is greater than the second correction zone curvature; A third front mold core is provided for generating the front surface of the protrusion having a third correction zone curvature, wherein the second correction zone curvature is greater than the third correction zone curvature; A set of rear mold cores is provided for generating the recessed rear surface with different radii of curvature, comprising a plurality of rear mold cores, each rear mold core being used to generate a rear surface having a corresponding radius of curvature; Provides a planar rear mold core for generating a planar rear surface; The first front mold core and the set of rear mold cores are used to generate the first set of annular focal lenses; The second front mold core and the set of rear mold cores are used to generate the second set of annular focal lenses; The third front mold core and the set of rear mold cores are used to generate the third set of annular focal lenses; The third front mold core and the planar rear mold core are used to generate a semi-finished lens; and The rear surface of the semi-finished lens undergoes secondary processing to produce the fourth set of annular focal lenses. The fourth set of annular focal lenses has a first refractive power of less than -6D or an astigmatism of less than -2D. Among them, the ring-focus lenses in the first set, second set, third set, and fourth set do not overlap in terms of myopia and astigmatism.

2. The method according to claim 1, wherein, The first set of ring-focus lenses has a first refractive power of -2D to 0D, the second set of ring-focus lenses has a first refractive power of -4D to -2D, and the third set of ring-focus lenses has a first refractive power of -6D to -4D.

3. The method according to claim 1, wherein, The curvature of the first correction zone is 401 to 600 bends, the curvature of the second correction zone is 201 to 400 bends, and the curvature of the third correction zone is 50 to 200 bends.

4. The method according to claim 1, wherein, This set of rear mold cores has 80 to 120 rear mold cores.

5. The method according to claim 1, wherein, The center thickness of the semi-finished lens ranges from 2mm to 20mm.

6. The method according to claim 1, wherein, The threshold is 3.5D.

7. The method according to claim 1, wherein, The freeform surface of the front surface is formed by a generatrix rotating along the optical axis. The generatrix is ​​composed of multiple first curves and multiple second curves. Each first curve has the radius of curvature of the first surface, and each second curve has the radius of curvature of the second surface. The first curves and second curves intersect in the generatrix. The first curves rotate to form the first surface, and the second curves rotate to form the second surface. The generatrix is ​​a continuous and smooth curve without protrusions or depressions.

8. The method according to claim 1, wherein, The rear surface is a spherical surface, an even-order aspherical surface, or a biconical surface.

Images