Toric surface ophthalmic lens and curved surface calculation method of toric surface ophthalmic lens

Abstract

The invention provides a toric ophthalmic lens and a curved surface calculation method of the toric ophthalmic lens, and relates to the technical field of ophthalmic optics. The toric ophthalmic lens is used for correcting astigmatism of human eyes; an optical part of the lens is provided with a geometric center, in a circular or annular range with the geometric center as a circle center, the focal power distribution trends in two radial directions on the same diameter are symmetrical about the geometric center, and the focal power distribution trends in the radial directions corresponding to any two different angles are the same. According to the toric ophthalmic lens provided by the invention, the distribution trends of the focal powers in the two radial directions on the same diameter are symmetrical about the geometric center, and the distribution trends of the focal powers in the radial directions corresponding to any two different angles are the same; while astigmatism correction is achieved, it is guaranteed that functionality in any radial direction is the same, and the overall optical performance of the lens is more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of ophthalmology, and in particular to a toric ophthalmic lens and a surface calculation method of the toric ophthalmic lens. Background Art

[0002] Refractive errors include myopia, hyperopia, and astigmatism, with 50% or more of patients with refractive errors experiencing astigmatism. Over 80% of the human cornea is affected by astigmatism. Astigmatism correction lenses are in widespread demand across a wide range of ophthalmic lenses, including spectacles, contact lenses, phakic and aphakic intraocular lenses.

[0003] At the same time, with the advancement of optical design technology and the diversification of individual needs, the functions of ophthalmic lenses are no longer limited to simple vision correction, but are pursuing more diverse and high-quality optical functions. For example, functional ophthalmic lenses can adjust spherical aberration, slow the progression of myopia, extend depth of field, and relieve visual fatigue.

[0004] Astigmatism correction lenses are implemented using toric surfaces, while functional optical lenses are often realized using multiple spherical or aspheric arcs. Both toric and aspheric surfaces are complex optical surfaces, making their calculation and implementation relatively complex. Existing technology typically designs toric and aspheric surfaces separately on the front and back surfaces of a lens, combining them to achieve both functional and astigmatism correction. However, this combination can result in varying functionality across different radial directions, leading to differences in overall functionality compared to expectations.

[0005] A characteristic of toric lenses is that their optical surface shapes vary across different radial directions, thereby achieving varying optical powers and correcting astigmatism. Functional optical designs are often implemented through aspheric, multi-segment spherical, or freeform surfaces. These often have complex surface formulas or distributions, making it difficult to precisely match each radial direction with the toric surface.

[0006] like Figure 1 As shown in the figure, a zero-spherical-aberration lens uses an aspheric front surface to achieve zero spherical aberration, while the back surface is a toric surface to correct astigmatism. While the lens achieved in this manner meets zero-spherical-aberration functionality along radial direction 1, it does not fully meet zero-spherical-aberration functionality along radial direction 2. The key point is that the toric surface has different radial focal powers and different optical surface shapes. To achieve the same functionality for different optical surface shapes, the functional surface shape of the other surface must also change along the radial direction, requiring separate functional designs for different radial directions. Summary of the Invention

[0007] The present invention provides a complex curved ophthalmic lens, which is used to solve the problem in the prior art that it is impossible to achieve precise matching between each radial direction and the complex curved surface.

[0008] The present invention provides a toric ophthalmic lens for correcting astigmatism of the human eye; the optical portion of the lens has a geometric center, and within a circular or annular range with the geometric center as the center, the optical power distribution trends in two radial directions on the same diameter are symmetrical about the geometric center, and the optical power distribution trends in any two radial directions corresponding to different angles are the same.

[0009] According to a toric ophthalmic lens provided by the present invention, at least one surface of the optical portion satisfies: with the geometric center of the surface as the origin {0, 0, 0}, the {X, Y, 0} plane being tangent to the geometric center, and a three-dimensional coordinate system being established with the direction of minimum average optical power φ of the lens as the X-axis, then any point {x, y, Z(x, y)} on the surface satisfies the following formula (1); (1) Among them, h f (x, y) is the optical curve distribution function in the direction of minimum optical power φ; h s (x, y) is the optical curve distribution function in the direction perpendicular to the direction of minimum optical power φ, and h s (x, y) ≠ h f (x, y).

[0010] According to a toric ophthalmic lens provided by the present invention, the diameter of the optical portion is D, and x, y and D satisfy the following formula (2); (2).

[0011] According to a toric ophthalmic lens provided by the present invention, the h s (x, y) and h f (x, y) are both even-order aspheric curves, odd-order aspheric curves, cubic spline curves or free curves.

[0012] According to a toric ophthalmic lens provided by the present invention, in the h s (x, y) and h f When (x, y) are both even-order aspheric curves, the aspheric coefficient Q and the even-order aspheric high-order coefficients in any radial direction are not exactly the same.

[0013] According to a toric ophthalmic lens provided by the present invention, any radial direction of the surface is an aspherical arc and has at least two curvatures.

[0014] According to a complex ophthalmic lens provided by the present invention, the surface has a radial spherical arc with one curvature; the remaining radial directions are all aspherical arcs with at least two curvatures.

[0015] According to a toric ophthalmic lens provided by the present invention, within a circle with the geometric center as the center, the optical focal power of the radius r corresponding to any radial direction satisfies the following formula (3): φ(r)=φ(-r) (3) Among them, r∈(0, ] .

[0016] According to a toric ophthalmic lens provided by the present invention, the radial power distribution trend corresponding to any two angles θ1 and θ2 Satisfy the following formula (4); = (4) in, θ 1 ∈[0°,360°), θ 2 ∈[0°,360°) ,and θ 1 ≠θ 2 .

[0017] According to a toric ophthalmic lens provided by the present invention, the lens includes extraocular frame glasses, and the diameter of the optical part of the extraocular frame glasses is 40-80 mm.

[0018] According to a toric ophthalmic lens provided by the present invention, the lens includes a contact lens, which is a corneal contact lens or a scleral contact lens, and the diameters of the corneal contact lens optical part and the scleral contact lens optical part are both 7-12 mm.

[0019] According to the present invention, a toric ophthalmic lens is provided, wherein the lens comprises an intraocular phakic intraocular lens, and the diameter of the optical portion of the intraocular phakic intraocular lens is 4-8 mm.

[0020] According to the present invention, a toric ophthalmic lens is provided, wherein the lens comprises an aphakic intraocular lens, and the diameter of the optical portion of the aphakic intraocular lens is 4-8 mm.

[0021] The present invention further provides a method for calculating the curved surface of a toric ophthalmic lens, the method being used to calculate the curved surface of any of the above-mentioned toric ophthalmic lenses, comprising: Determining the surface of the lens and the size parameters of the lens; Establishing a three-dimensional coordinate system based on the geometric center of the surface as the origin; Calculate the optical curve distribution function h in the X-axis direction s (x,y) and the optical curve distribution function h in the Y-axis direction f (x,y); Calculate {x, y, Z(x, y)} at any point on the surface to obtain an |X, Y, Z| lattice; The surface shape is obtained by interpolation method based on the |X, Y, Z| point matrix.

[0022] According to a surface calculation method of a complex ophthalmic lens provided by the present invention, the three-dimensional coordinate system takes the geometric center of the surface as the origin {0, 0, 0}, the {X, Y, 0} plane is tangent to the geometric center, and the average optical power of the lens is φ The minimum direction is the X axis.

[0023] According to a method for calculating the curved surface of a complex ophthalmic lens provided by the present invention, the h s The optical power distribution trend in the radial direction of (x, y) is consistent with the h f The optical power distribution trend in the radial direction of (x, y) is the same, that is .

[0024] According to a method for calculating the curved surface of a complex ophthalmic lens provided by the present invention, the interpolation method includes a spline interpolation method, a polynomial interpolation method or a least squares interpolation method.

[0025] The toric ophthalmic lens provided by the present invention makes the optical power distribution trends in two radial directions on the same diameter symmetrical about the geometric center, and makes the optical power distribution trends in any two radial directions corresponding to different angles identical. While achieving astigmatism correction, it ensures the same functionality in any radial direction, and the overall optical performance of the lens is more precise. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 This is a schematic diagram of the zero spherical aberration function effect achieved by the zero spherical aberration lens in the prior art provided by the present invention.

[0028] Figure 2 This is a rendering of the different radial focal power distribution trends of the existing lens provided by the first embodiment of the present invention.

[0029] Figure 3 This is a schematic diagram of establishing a three-dimensional coordinate system based on the geometric center as the origin provided by the first embodiment of the present invention.

[0030] Figure 4This is a schematic diagram of dot matrix distribution provided by the first embodiment of the present invention.

[0031] Figure 5 The first embodiment of the present invention provides a method for constructing a 3D surface graph using an interpolation method.

[0032] Figure 6 Schematic diagram of the curvature distribution of the rear surface provided by the first embodiment of the present invention.

[0033] Figure 7 This is a lens wavefront diagram provided by the first embodiment of the present invention.

[0034] Figure 8 This is a schematic diagram of the distribution trend of different radial optical powers provided by the first embodiment of the present invention.

[0035] Figure 9 This is a rendering of different radial focal power distribution trends of an existing lens provided by the second embodiment of the present invention.

[0036] Figure 10 This is a schematic diagram of establishing a three-dimensional coordinate system based on the geometric center as the origin, provided by the second embodiment of the present invention.

[0037] Figure 11 This is a schematic diagram of dot matrix distribution provided by the second embodiment of the present invention.

[0038] Figure 12 The second embodiment of the present invention provides a method for constructing a 3D surface graph using an interpolation method.

[0039] Figure 13 Schematic diagram of the curvature distribution of the rear surface provided by the second embodiment of the present invention.

[0040] Figure 14 This is a lens wavefront diagram provided by the second embodiment of the present invention.

[0041] Figure 15 1 is a schematic diagram of different radial optical power distribution trends provided by the second embodiment of the present invention.

[0042] Figure 16 This is a rendering of different radial focal power distribution trends of an existing lens provided by the third embodiment of the present invention.

[0043] Figure 17 This is a schematic diagram of establishing a three-dimensional coordinate system based on the geometric center as the origin, provided by the third embodiment of the present invention.

[0044] Figure 18 This is a schematic diagram of dot matrix distribution provided by the third embodiment of the present invention.

[0045] Figure 19 The third embodiment of the present invention provides a method for constructing a 3D surface graph using an interpolation method.

[0046] Figure 20 Schematic diagram of the curvature distribution of the rear surface provided by the third embodiment of the present invention.

[0047] Figure 21 This is a lens wavefront diagram provided by the third embodiment of the present invention.

[0048] Figure 22 1 is a schematic diagram of different radial optical power distribution trends provided by the third embodiment of the present invention.

[0049] Figure 23 This is a rendering of different radial focal power distribution trends of an existing lens provided by the fourth embodiment of the present invention.

[0050] Figure 24 This is a schematic diagram of establishing a three-dimensional coordinate system based on the geometric center as the origin, provided by the fourth embodiment of the present invention.

[0051] Figure 25 This is a schematic diagram of dot matrix distribution provided by the fourth embodiment of the present invention.

[0052] Figure 26 The fourth embodiment of the present invention provides a method of constructing a 3D surface graph using an interpolation method.

[0053] Figure 27 Schematic diagram of the curvature distribution of the rear surface provided by the fourth embodiment of the present invention.

[0054] Figure 28 This is a lens wavefront diagram provided by the fourth embodiment of the present invention.

[0055] Figure 29 4 is a schematic diagram of different radial optical power distribution trends provided by the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0056] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0057] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0058] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on the specific circumstances.

[0059] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0060] Before introducing toric ophthalmic lenses and the method for calculating the curvature of toric ophthalmic lenses, the following related terms are explained.

[0061] Toric surface: In the field of ophthalmic lenses, it generally refers to a surface that contains at least two curvatures, with the maximum and minimum curvature directions perpendicular to each other. Toric lenses are mainly used to correct astigmatism in the human eye.

[0062] Radial: The direction of a straight line from the center of the lens along a radius or diameter.

[0063] Three-dimensional coordinate system: A three-dimensional coordinate system in which the XYZ axes are in different and perpendicular directions.

[0064] Radial distribution trend of optical power: the trend of the curve of the lens optical power changing with radius.

[0065] Ra: radius of curvature of the front surface vertex.

[0066] Rat: The vertex curvature radius of the front surface in the direction perpendicular to Ra.

[0067] Rp: radius of curvature of the posterior surface vertex.

[0068] Rpt: The vertex curvature radius of the back surface in the direction perpendicular to Rp.

[0069] Qa: aspheric coefficient of the front surface.

[0070] Qp: aspheric coefficient of the back surface.

[0071] A4, ..., A16: coefficients of higher-order terms of even-order aspheric surfaces, whose expressions on the aspheric curve along the Z axis are as follows: Where c is the curvature of the lens and r is the geometric radius of the lens.

[0072] When Q = A4 = ... = A16 = 0, the surface is a sphere. 2i ≠0, for example, when at least one of A4, ...A16 is not zero, the surface is a high-order aspheric surface.

[0073] The following combination Figures 2 to 29 The specific structure and performance of the toric ophthalmic lens of the present invention are described.

[0074] Toric ophthalmic lenses are used to correct astigmatism of the human eye; the optical portion of the lens has a geometric center. Within a circular or annular area with the geometric center as the center, the optical power distribution trends in two radial directions on the same diameter are symmetrical about the geometric center, and the optical power distribution trends in any two radial directions corresponding to different angles are the same.

[0075] The toric ophthalmic lens provided by the present invention makes the optical power distribution trends in two radial directions on the same diameter symmetrical about the geometric center, and makes the optical power distribution trends in any two radial directions corresponding to different angles identical. While achieving astigmatism correction, it ensures the same functionality in any radial direction, and the overall optical performance of the lens is more precise.

[0076] It should be noted that toric ophthalmic lenses include but are not limited to extraocular spectacles, contact lenses, intraocular phakic intraocular lenses and aphakic intraocular lenses.

[0077] In one embodiment of the present invention, at least one surface of the optical portion satisfies the following: with the geometric center of the surface as the origin {0, 0, 0}, that is, the origin O of a three-dimensional coordinate system is established, the {X, Y, 0} plane is tangent to the geometric center, and a three-dimensional coordinate system is established with the minimum direction of the average optical power φ of the lens as the X-axis. Then, any point {x, y, Z(x, y)} on the surface satisfies the following formula (1): (1) Among them, h f (x, y) is the optical curve distribution function in the direction of minimum optical power φ, h s (x, y) is the optical curve distribution function in the direction perpendicular to the direction of minimum optical power φ, and h s (x, y) ≠ h f (x, y).

[0078] h s (x, y) and h f The surface design method in the radial direction of (x, y) is related to the expected function of the lens, which includes the control of aberrations, delaying the progression of myopia, extending the depth of field, and precise matching with other structures. The optical surface shape of the lens cannot be described by a spherical arc.

[0079] In guarantee h s (x, y) and h f When the power distribution trend in the radial direction of (x, y) is the same, the sagittal height at any position on the lens surface is calculated using formula (1), which can ensure that the power distribution trend in any radial direction of the optical part of the complex ophthalmic lens is exactly the same, thereby achieving precise and consistent optical functionality in all directions.

[0080] In one embodiment of the present invention, the optical curvature shape of at least one surface of the optical portion of the toric ophthalmic lens along any radial direction passing through the geometric center is a non-single curvature spherical arc.

[0081] In one embodiment of the present invention, the diameter of the optical portion is D, then x, y and D satisfy the following formula (2); (2) It should be noted here that (x, y) is a point in the |X, Y, Z| lattice.

[0082] In one embodiment of the present invention, h s (x, y) and h f (x, y) are all even-order aspheric curves, odd-order aspheric curves, cubic spline curves or free curves. s (x, y) and h f (x, y) are both even-order aspheric curves.

[0083] In one embodiment of the present invention, s (x, y) and h f When (x, y) are both even-order aspheric curves, the aspheric coefficient Q and the even-order aspheric high-order coefficients in any radial direction are not exactly the same, that is, the aspheric coefficient Q in any radial direction is not exactly the same, and the even-order aspheric high-order coefficients A4, ...A16 are not exactly the same.

[0084] In one embodiment of the present invention, any radial direction of the surface is an aspherical arc and has at least two curvatures.

[0085] In one embodiment of the present invention, the surface has a radial direction that is a spherical arc with one curvature; the remaining radial directions are all aspherical arcs with at least two curvatures.

[0086] In one embodiment of the present invention, within a circle with the geometric center as the center, the optical focal length of the radius r corresponding to any radial direction satisfies the following formula (3); φ(r)=φ(-r) (3) Among them, r∈(0, It should be noted that φ(r) is the optical focal length in the radial direction of the radius r, and φ(-r) is the optical focal length in the radial direction of the radius that is symmetrical to the radius r about the geometric center.

[0087] In one embodiment of the present invention, the radial power distribution trend corresponding to any two angles θ1 and θ2 is Satisfy the following formula (4); = (4) in, θ 1 ∈[0°,360°), θ 2 ∈[0°,360°) ,and θ 1 ≠θ 2 .

[0088] In one embodiment of the present invention, the lens comprises an extraocular frame spectacles, and the diameter of the optical portion of the extraocular frame spectacles is 40-80 mm. Preferably, the diameter of the optical portion of the extraocular frame spectacles is 60-80 mm.

[0089] In one embodiment of the present invention, the lens comprises a contact lens, wherein the contact lens is a corneal contact lens or a scleral contact lens, and the diameter of the corneal contact lens optic and the scleral contact lens optic are both 7 to 12 mm. Preferably, the diameter of the corneal contact lens optic and the scleral contact lens optic are both 8 to 10 mm.

[0090] In one embodiment of the present invention, the lens comprises a phakic intraocular lens, and the diameter of the optic of the phakic intraocular lens is 4 to 8 mm. Preferably, the diameter of the optic of the phakic intraocular lens is 4.5 to 6.5 mm.

[0091] In one embodiment of the present invention, the lens comprises an aphakic intraocular lens, and the diameter of the optic of the aphakic intraocular lens is 4-8 mm. Preferably, the diameter of the optic of the aphakic intraocular lens is 5-6.5 mm.

[0092] The present invention further provides a method for calculating the curved surface of a toric ophthalmic lens. The method is used to calculate the curved surface of the toric ophthalmic lens described in any one of the above embodiments. The method for calculating the curved surface of the toric ophthalmic lens comprises: Step S100, determining the surface and size parameters of the lens; Step S200, establishing a three-dimensional coordinate system based on the geometric center of the surface as the origin; Step S300, calculate the optical curve distribution function h in the X-axis direction s (x,y) and the optical curve distribution function h in the Y-axis direction f (x,y); Step S400 , calculating {x, y, Z(x, y)} at any point on the surface to obtain an |X, Y, Z| lattice; Step S500: Obtain the surface shape of the curved surface using an interpolation method according to the |X, Y, Z| point matrix.

[0093] In one embodiment of the present invention, the three-dimensional coordinate system takes the geometric center of the surface as the origin {0, 0, 0}, the {X, Y, 0} plane is tangent to the geometric center, and the average focal length of the lens is φ The minimum direction is the X axis.

[0094] In one embodiment of the present invention, h s The optical power distribution trend in the radial direction of (x,y) is related to h f The optical power distribution trend in the radial direction of (x, y) is the same, that is .

[0095] In one embodiment of the present invention, the interpolation method includes a spline interpolation method, a polynomial interpolation method or a least squares interpolation method.

[0096] The following combination Figures 2 to 8 The first embodiment of the present invention is described as follows. Figures 2 to 8As shown, the lens in this embodiment is an extended depth of field (EDF) astigmatism correction intraocular lens, the diameter of the lens optical part is 6.0 mm, the spherical power of the intraocular lens vertex is +10.0D, and the cylindrical power of the intraocular lens is +4.5D.

[0097] The existing lens generally has a rotationally symmetrical high-order aspheric surface design on the front / back surface to extend the depth of field, and a toric surface combined with a spherical surface design to correct astigmatism, as shown in Table 1 below. The radial power distribution trend of this lens is different, such as Figure 2 shown.

[0098] Table 1

[0099] In order to solve the above problems, the curved surface calculation method of the toric ophthalmic lens of the present invention is used to calculate the curved surface of the lens. The curved surface calculation method of the toric ophthalmic lens includes: Step S100, selecting the rear surface of the lens, the diameter of the optical part is 5.0 mm; Step S200, establishing a three-dimensional coordinate system based on the geometric center of the surface as the origin; The geometric center of the posterior surface is taken as the origin O = {0, 0, 0}, and the {X, Y, 0} plane is tangent to the geometric center to establish an XYZ three-dimensional coordinate system; wherein, the radial direction of the optical power of +10.0D (the radius of curvature of the posterior surface is -11.15mm) is the direction of minimum average optical power, which is the X axis; the radial direction of the optical power of +14.5D (the radius of curvature of the posterior surface is -6.25mm) is the Y axis, as shown in Figure 3 shown.

[0100] Step S300, calculate the optical curve distribution function h in the X-axis direction s (x,y) and the optical curve distribution function h in the Y-axis direction f (x,y); Calculate the optical surface formula h in the direction with the minimum average focal power (vertex focal power is +10.0D, curvature radius is -11.15mm) f Optical curve distribution function h in the direction (x, y) and perpendicular to it (vertex power is +14.5D, curvature radius is -6.25mm) s (x,y), where h s (x,y) and h f (x, y) should make the focal length distribution trend of the lens as a whole in the direction of minimum average focal length and in the direction perpendicular to it exactly the same. The calculation is made using the following formula (5).

[0101] (5) Step S400 , calculating {x, y, Z(x, y)} at any point on the surface to obtain an |X, Y, Z| lattice; According to formula (5) and formula (1), calculate any point {x, y, Z(x, y)} on the rear surface and select an interval of 0.05mm to form an |X, Y, Z| dot matrix, as shown in Figure 4 shown.

[0102] Step S500, constructing a 3D surface graph using a bicubic spline interpolation method based on the |X, Y, Z| point matrix; like Figure 5 As shown, the lens constructed according to the above steps has a high-order aspheric surface on the front surface and a curved surface on the back surface according to the present invention. The back surface has a single-curvature spherical arc only in the radial direction where the X-axis is located, and the curvature is -0.08968mm. -1 , and the rest of the directions are aspherical arcs with at least two curvatures.

[0103] The curvature distribution of the back surface is as follows Figure 6 As shown, the lens wavefront diagram is as follows Figure 7 As shown, the radial focal power distribution trends at 0° (X-axis direction), 90° (Y-axis direction), and 30°, 45°, and 60° are as follows: Figure 8 As shown, the radial power distribution trends are exactly the same. While achieving astigmatism correction, it ensures the same functionality in any radial direction, ensures the consistent depth of field extension effect in different directions, and improves the accuracy of the lens function.

[0104] The following combination Figures 9 to 15 Describe the second specific embodiment of the present invention, as Figures 9 to 15 As shown in the figure, the lens in this embodiment is a zero spherical aberration astigmatism correction type phakic intraocular lens with a spherical power of -20.0D and a cylindrical power of -5D. Conventional lenses generally have a rotationally symmetric high-order aspheric design on the front / back surface to achieve zero spherical aberration, and a toric combined spherical design on the other surface to achieve astigmatism correction, as shown in Table 2 below. The distribution trend of different radial focal powers of the lens is different, such as Figure 9 shown.

[0105] Table 2

[0106] In order to solve the above problems, the curved surface calculation method of the toric ophthalmic lens of the present invention is used to calculate the curved surface of the lens. The curved surface calculation method of the toric ophthalmic lens includes: Step S100, selecting the rear surface of the lens, the diameter of the optical part is 6.0 mm; Step S200, establishing a three-dimensional coordinate system based on the geometric center of the surface as the origin; The geometric center of the rear surface is taken as the origin O = {0, 0, 0}, and the {X, Y, 0} plane is tangent to the geometric center to establish an XYZ three-dimensional coordinate system; among them, the radial direction of the optical power of -25.0D (the radius of curvature of the front surface is -8.37mm) is the direction of minimum average optical power, which is the X axis; the radial direction of the optical power of -20.0D (the radius of curvature of the front surface is -15.04mm) is the Y axis, as shown in the following figure: Figure 10 shown.

[0107] Step S300, calculate the optical curve distribution function h in the X-axis direction s (x,y) and the optical curve distribution function h in the Y-axis direction f (x,y); Calculate the optical surface formula h in the direction of minimum average focal power (vertex focal power is -25.0D, curvature radius is -8.37mm) f Optical curve distribution function h in the direction (x, y) and perpendicular to it (vertex focal power is -20.0D, curvature radius is -15.04mm) s (x,y), where h s (x,y) and h f (x, y) should make the focal length distribution trend of the lens as a whole in the direction of minimum average focal length and in the direction perpendicular to it exactly the same. The following formula (6) is used for calculation.

[0108] (6).

[0109] Step S400 , calculating {x, y, Z(x, y)} at any point on the surface to obtain an |X, Y, Z| lattice; According to formula (6) and formula (1), calculate any point {x, y, Z(x, y)} on the rear surface and select an interval of 0.1mm to form an |X, Y, Z| dot matrix, as shown in Figure 11 shown.

[0110] Step S500, constructing a 3D surface graph using a bicubic spline interpolation method based on the |X, Y, Z| point matrix; like Figure 12 As shown, the lens constructed according to the above steps has a front surface that is a complex surface combined with a spherical surface, and a back surface that is a curved surface according to the present invention, wherein any radial direction of the back surface is an aspheric arc with at least two curvatures.

[0111] The curvature distribution of the back surface is as follows Figure 13 As shown, the lens wavefront diagram is as follows Figure 14 As shown, the radial focal power distribution trends at 0° (X-axis direction), 90° (Y-axis direction), and 30°, 45°, and 60° are as follows: Figure 15As shown, the radial power distribution trends are exactly the same. While achieving astigmatism correction, it ensures the same functionality in any radial direction, ensures the consistent depth of field extension effect in different directions, and improves the accuracy of the lens function.

[0112] The following combination Figures 16 to 22 Describe the third specific embodiment of the present invention, as Figures 16 to 22 As shown, the lens in this embodiment is a progressive focus contact lens used to slow the progression of myopia. The diameter of the optical portion is 8.0 mm, the vertex spherical power of the lens is -6.0 D, and the cylindrical power of the lens is -4.0 D. Conventional lenses generally have a front surface that is a rotationally symmetrical one-segment or multi-segment aspheric design to achieve a progressive focus optical zone, and another surface that is a toric combined with a spherical surface or a toric combined with an aspheric design with the same aspheric coefficient (Q) to achieve astigmatism correction, as shown in Table 3 below. The distribution trend of different radial focal powers of the lens is different, such as Figure 16 shown.

[0113] Table 3

[0114] In order to solve the above problems, the curved surface calculation method of the toric ophthalmic lens of the present invention is used to calculate the curved surface of the lens. The curved surface calculation method of the toric ophthalmic lens includes: Step S100, selecting the rear surface of the lens, the diameter of the optical part is 8.0 mm; Step S200, establishing a three-dimensional coordinate system based on the geometric center of the surface as the origin; The geometric center of the posterior surface is taken as the origin O = {0, 0, 0}, and the {X, Y, 0} plane is tangent to the geometric center to establish an XYZ three-dimensional coordinate system; among them, the radial direction of the optical power of -10.0D (the radius of curvature of the posterior surface is 8.49mm) is the direction of minimum average optical power, which is the X-axis; the radial direction of the optical power of -6.0D (the radius of curvature of the posterior surface is 9.00mm) is the Y-axis, as shown in Figure 17 shown.

[0115] Step S300, calculate the optical curve distribution function h in the X-axis direction s (x,y) and the optical curve distribution function h in the Y-axis direction f (x,y); Calculate the optical surface formula h in the direction with the minimum average focal power (vertex focal power is -10.0D, curvature radius is 8.49mm) f Optical curve distribution function h in the direction (x, y) and perpendicular to it (vertex focal power is -6.0D, curvature radius is 9.00mm) s (x,y), where h s (x,y) and h f(x, y) should make the focal length distribution trend of the lens as a whole in the direction of minimum average focal length and in the direction perpendicular to it exactly the same. The calculation is carried out using the following formula (7).

[0116] (7) Step S400 , calculating {x, y, Z(x, y)} at any point on the surface to obtain an |X, Y, Z| lattice; According to formula (7) and formula (1), calculate any point {x, y, Z(x, y)} on the rear surface and select an interval of 0.2mm to form an |X, Y, Z| dot matrix, as shown in Figure 18 shown.

[0117] Step S500, constructing a 3D surface graph using a bicubic spline interpolation method based on the |X, Y, Z| point matrix; like Figure 19 As shown, the lens constructed according to the above steps has a high-order aspheric surface on the front surface and a curved surface as described in the present invention, wherein any radial direction of the rear surface is an aspheric arc with at least two curvatures.

[0118] The curvature distribution of the back surface is as follows Figure 20 As shown, the lens wavefront diagram is as follows Figure 21 As shown, the radial focal power distribution trends at 0° (X-axis direction), 90° (Y-axis direction), and 30°, 45°, and 60° are as follows: Figure 22 As shown in the figure, the radial focal power distribution trends are exactly the same, which ensures the same defocus amount in different directions while achieving astigmatism correction, thereby improving the accuracy of the lens function.

[0119] The following combination Figures 23 to 29 Describe the fourth specific embodiment of the present invention, as Figures 23 to 29 As shown, the lens in this embodiment is a progressive light zone frame glasses used to relieve visual fatigue. The diameter of the optical part is 70.0mm, the vertex spherical power of the lens is -2.0D, and the cylindrical power of the lens is -0.5D. The existing lenses generally have a front surface with a rotationally symmetrical one or more-segment aspheric design to achieve a progressive light zone, and the other surface is a complex surface combined with a spherical surface or a complex surface combined with an aspheric design with the same aspheric coefficient (Q) to achieve astigmatism correction, or the front surface / back surface is a toric surface design defined by a set of high-order aspheric formulas, as shown in Table 4 below. The different radial focal power distribution trends of the lens are different, such as Figure 23 shown.

[0120] Table 4

[0121] In order to solve the above problems, the curved surface calculation method of the toric ophthalmic lens of the present invention is used to calculate the curved surface of the lens. The curved surface calculation method of the toric ophthalmic lens includes: Step S100, selecting the front surface of the lens, wherein the optical portion is a ring with an inner diameter of 2.0 mm and an outer diameter of 70 mm; Step S200, establishing a three-dimensional coordinate system based on the geometric center of the surface as the origin; The geometric center of the rear surface is taken as the origin O = {0, 0, 0}, and the {X, Y, 0} plane is tangent to the geometric center to establish an XYZ three-dimensional coordinate system; among them, the radial direction of the optical power of -2.5D (the radius of curvature of the front surface is 86.28mm) is the direction of minimum average optical power, which is the X axis; the radial direction of the optical power of -2.0D (the radius of curvature of the front surface is 79.50mm) is the Y axis, as shown in Figure 24 shown.

[0122] Step S300, calculate the optical curve distribution function h in the X-axis direction s (x,y) and the optical curve distribution function h in the Y-axis direction f (x,y); Calculate the optical surface formula h in the direction with the minimum average focal power (vertex focal power is -2.5D, curvature radius is 86.28mm) f Optical curve distribution function h in the direction (x, y) and perpendicular to it (vertex focal power is -2.0D, curvature radius is 79.50mm) s (x,y), where h s (x,y) and h f (x, y) should make the focal length distribution trend of the lens as a whole in the direction of minimum average focal length and in the direction perpendicular to it exactly the same. The following formula (8) is used for calculation.

[0123] (8).

[0124] Step S400 , calculating {x, y, Z(x, y)} at any point on the surface to obtain an |X, Y, Z| lattice; According to formula (8) and formula (1), calculate any point {x, y, Z(x, y)} on the rear surface and select an interval of 0.5mm to form an |X, Y, Z| dot matrix, as shown in Figure 25 shown.

[0125] Step S500, constructing a 3D surface graph using a bicubic spline interpolation method based on the |X, Y, Z| point matrix; like Figure 26As shown, the lens constructed according to the above steps has a spherical back surface and a curved front surface as described in the present invention. The front surface is a complex curved surface combined with a high-order aspheric surface. The aspheric coefficient Q and the even-order aspheric coefficients A4, A6, and A8 in any radial direction are not completely identical. The even-order aspheric coefficient A8 is the same at 0° (X-axis direction) and 90° (Y-axis direction), while the aspheric coefficient Q and the even-order aspheric coefficients A4 and A6 are different. The front surface is an aspheric arc in any radial direction, with at least two curvatures.

[0126] The curvature distribution of the back surface is as follows Figure 27 As shown, the lens wavefront diagram is as follows Figure 28 As shown, the radial focal power distribution trends at 0° (X-axis direction), 90° (Y-axis direction), and 30°, 45°, and 60° are as follows: Figure 29 As shown in the figure, the radial focal power distribution trends are exactly the same, which ensures the same defocus amount in different directions while achieving astigmatism correction, thereby improving the accuracy of the lens function.

[0127] The surface calculation method for toric ophthalmic lenses provided by this invention is applicable to the positioning of toric surfaces in ophthalmic lenses, such as the positioning calculation of the inner surface of a contact lens (the surface in contact with the eye) and the calculation of the positioning arc of orthokeratology lenses. It is particularly suitable for calculating toric surfaces of lenses with varying eccentricities in the flat and steep directions of the cornea.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A toric ophthalmic lens for correcting astigmatism of the human eye; characterized in that: The optical portion of the lens has a geometric center. Within a circular or annular range with the geometric center as the center, the optical power distribution trends in two radial directions on the same diameter are symmetrical about the geometric center, and the optical power distribution trends in the radial directions corresponding to any two different angles are the same.

2. The toric ophthalmic lens according to claim 1, wherein: At least one surface of the optical portion satisfies: a three-dimensional coordinate system is established with the geometric center of the surface as the origin {0, 0, 0}, a plane {X, Y, 0} is tangent to the geometric center, and the direction of minimum average optical power φ of the lens is used as the X-axis. Then, any point {x, y, Z(x, y)} on the surface satisfies the following formula (1); （1） Among them, h f (x, y) is the optical curve distribution function in the direction of minimum optical power φ; h s (x, y) is the optical curve distribution function in the direction perpendicular to the direction of minimum optical power φ, and h s (x, y) ≠ h f (x, y).

3. The toric ophthalmic lens according to claim 2, wherein: The diameter of the optical part is D, then x, y and D satisfy the following formula (2); （2）。 4. The toric ophthalmic lens according to claim 2, wherein: The h s (x, y) and h f (x, y) are both even-order aspheric curves, odd-order aspheric curves, cubic spline curves or free curves.

5. The toric ophthalmic lens according to claim 4, wherein: In the h s (x, y) and h f When (x, y) are both even-order aspheric curves, the aspheric coefficient Q and the even-order aspheric high-order coefficients in any radial direction are not exactly the same.

6. The toric ophthalmic lens according to any one of claims 2 to 5, characterized in that: Any radial direction of the surface is an aspherical arc and has at least two curvatures.

7. The toric ophthalmic lens according to any one of claims 2 to 5, characterized in that: The surface has a radial direction which is a spherical arc and has one curvature; the remaining radial directions are all aspherical arcs and have at least two curvatures.

8. The toric ophthalmic lens according to any one of claims 1 to 5, characterized in that: Within the circle with the geometric center as the center, the optical focal length of any radial direction corresponding to the radius r satisfies the following formula (3): φ(r)=φ(-r) (3) Among them, r∈(0, ] .

9. The toric ophthalmic lens according to any one of claims 1 to 5, characterized in that: The radial power distribution trend corresponding to any two angles θ1 and θ2 Satisfy the following formula (4); = （4） in, θ 1 ∈[0°,360°), θ 2 ∈[0°,360°) ,and θ 1 ≠θ 2 .

10. The toric ophthalmic lens according to any one of claims 1 to 5, characterized in that The lens includes extraocular frame glasses, and the diameter of the optical part of the extraocular frame glasses is 40~80mm.

11. The toric ophthalmic lens according to any one of claims 1 to 5, characterized in that: The lens includes a contact lens, which is a corneal contact lens or a scleral contact lens. The diameters of the corneal contact lens optical part and the scleral contact lens optical part are both 7-12 mm.

12. The toric ophthalmic lens according to any one of claims 1 to 5, characterized in that: The lens comprises an intraocular phakic intraocular lens, and the diameter of the optical part of the intraocular phakic intraocular lens is 4-8 mm.

13. The toric ophthalmic lens according to any one of claims 1 to 5, characterized in that: The lens comprises an aphakic intraocular lens, and the diameter of the optical part of the aphakic intraocular lens is 4-8 mm.

14. A method for calculating the curved surface of a toric ophthalmic lens, the method being used to calculate the curved surface of the toric ophthalmic lens according to any one of claims 1 to 13, characterized in that: include: determining the surface of the lens and the size parameters of the lens; Establishing a three-dimensional coordinate system based on the geometric center of the surface as the origin; Calculate the optical curve distribution function h in the X-axis direction s (x,y) and the optical curve distribution function h in the Y-axis direction f (x,y); Calculate {x, y, Z(x, y)} at any point on the surface to obtain an |X, Y, Z| lattice; The surface shape is obtained by interpolation method based on the |X, Y, Z| point matrix.

15. The method for calculating the curved surface of a toric ophthalmic lens according to claim 14, wherein: The three-dimensional coordinate system takes the geometric center of the surface as its origin {0, 0, 0}, the {X, Y, 0} plane is tangent to the geometric center, and the average focal length of the lens is φ The minimum direction is the X axis.

16. The method for calculating the curved surface of a toric ophthalmic lens according to claim 14, wherein: The h s The optical power distribution trend in the radial direction of (x, y) is consistent with the h f The optical power distribution trend in the radial direction of (x, y) is the same, that is .

17. The method for calculating the curved surface of a toric ophthalmic lens according to claim 14, wherein: The interpolation method includes a spline interpolation method, a polynomial interpolation method or a least squares interpolation method.

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