Toric surface ophthalmic lens
By designing the symmetry of the optical power distribution trend and the three-dimensional coordinate system interpolation method in the complex curved ophthalmic lens, the problem of inaccurate radial matching was solved, and accurate astigmatism correction and functional consistency of the lens were achieved.
Patent Information
- Application Number
- CN202422666512.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-01
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-11-01
AI Technical Summary
Existing technologies are unable to achieve precise matching of all radial directions of complex curved lenses, resulting in differences in the functionality of lenses in different radial directions and the overall functionality not meeting expectations.
A complex ophthalmic lens is designed to make the optical power distribution trends in two radial directions on the same diameter symmetrical about the geometric center, and to make the optical power distribution trends in any two radial directions corresponding to different angles the same. By establishing a three-dimensional coordinate system and interpolation method to construct a 3D surface, the functional consistency of any radial direction is ensured.
The toric lens can correct astigmatism while ensuring the same functionality in any radial direction. The overall optical performance of the lens is more precise, improving the accuracy and consistency of the function.
Smart Images
Figure CN223486218U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of ophthalmic optics technology, and in particular to a tortuous ophthalmic lens. Background Technology
[0002] Refractive errors in the human eye include myopia, hyperopia, and astigmatism, with astigmatism accounting for 50% or more of all refractive error patients. More than 80% of the human cornea has astigmatism. Astigmatism-correcting lenses are in high demand across various ophthalmic lenses, including eyeglasses, contact lenses, intraocular lenses (phakic and aphakic).
[0003] Meanwhile, with the diversification of optical design technology and individual needs, the function of ophthalmic lenses is no longer limited to simple vision correction, but pursues more diversified and high-quality optical functions. These include functional ophthalmic lenses that adjust spherical aberration, slow myopia progression, extend depth of field, and relieve eye strain.
[0004] Astigmatism-correcting lenses are achieved through toric surface designs, while functional optical lenses are often realized through multiple spherical or aspherical arcs. Both toric and aspherical surfaces are complex optical surfaces, and their calculation and implementation are relatively complicated. Current technology typically designs the toric and aspherical surfaces separately on the front and rear surfaces of the lens, combining them to achieve both functional and astigmatism-correcting capabilities. However, this combination method results in variations in the lens's functionality across different radial directions, leading to a discrepancy between the overall functionality and the expected performance.
[0005] The characteristic of toric lenses lies in the fact that the shapes of their different radial optical surfaces are different, thereby achieving different optical powers and realizing the function of astigmatism correction. Functional optical design is often achieved through aspherical surfaces, multi-spherical surfaces, or freeform surfaces, which often have relatively complex surface formulas or distributions, making it difficult to achieve precise matching between each radial surface and the toric surface.
[0006] like Figure 1 As shown, a certain zero-spherical-aberration lens has an aspherical front surface designed to achieve zero-spherical-aberration functionality, and a toric surface on the rear surface designed to achieve astigmatism correction functionality. The lens achieves this functionality in radial direction 1, but not entirely in radial direction 2. The key point is that the optical power and optical surface shape differ in different radial directions of the toric surface. To achieve the same functionality for different optical surface shapes, the functional surface shape of the other side needs to also change along the radial direction, requiring separate functional designs for each radial direction. Utility Model Content
[0007] This invention provides a toroidal ophthalmic lens to solve the problem that existing technologies cannot achieve precise matching between each radial direction and the toroidal surface.
[0008] This invention provides a toric ophthalmic lens for correcting astigmatism in the human eye; the optical part of the lens has a geometric center, and within a circular or annular area centered on the geometric 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.
[0009] According to the present invention, at least one surface of the optical part satisfies the following: with the geometric center of the surface as the origin {0, 0, 0}, the plane {X, Y, 0} is tangent to the geometric center, and a three-dimensional coordinate system is 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).
[0010] (1)
[0011] Among them, h f (x, y) is the optical curve distribution function along 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).
[0012] According to the present invention, a toric ophthalmic lens is provided, wherein the diameter of the optical part is D, and x, y and D satisfy the following formula (2).
[0013] (2).
[0014] According to the present invention, a toric ophthalmic lens is provided, wherein h s (x, y) and the h f (x, y) are all even-order aspherical curves, odd-order aspherical curves, cubic spline curves, or free curves.
[0015] According to the present invention, a toric ophthalmic lens is provided, in the h s (x, y) and the h f When (x, y) are both even-order aspherical curves, the aspherical coefficient Q on any radial direction and the coefficient of the higher-order even-order aspherical term are not completely the same.
[0016] According to the present invention, a toric ophthalmic lens is provided, wherein any radial direction of the surface is an aspherical arc and has at least two curvatures.
[0017] According to the present invention, a toric ophthalmic lens has a radial spherical arc with a curvature; the remaining radial surfaces are aspherical arcs with at least two curvatures.
[0018] According to the present invention, the optical power of any radial radius r within a circle centered at the geometric center satisfies the following formula (3).
[0019] φ(r)=φ(-r) (3)
[0020] Where r∈(0, ] .
[0021] According to the toric ophthalmic lens provided by this utility model, the radial optical power distribution trend corresponding to any two angles θ1 and θ2 is shown. The following formula (4) must be satisfied;
[0022] = (4)
[0023] in, θ 1 ∈[0°,360°), θ 2 ∈[0°,360°) ,and θ 1 ≠θ 2 .
[0024] According to the present invention, a toric ophthalmic lens is provided, the lens comprising an external eyeglass frame, wherein the diameter of the optical part of the external eyeglass frame is 40~80mm.
[0025] According to the present invention, a toric ophthalmic lens includes a contact lens, which is a corneal contact lens or a scleral contact lens, and the diameters of the optical parts of the corneal contact lens and the optical parts of the scleral contact lens are both 7~12mm.
[0026] According to the present invention, a toric ophthalmic lens is provided, the lens including an intraocular phakic intraocular lens, wherein the diameter of the optical part of the intraocular phakic intraocular lens is 4~8mm.
[0027] According to the present invention, a toric ophthalmic lens is provided, the lens comprising an aphakic intraocular lens, wherein the diameter of the optical part of the aphakic intraocular lens is 4-8 mm.
[0028] The toric ophthalmic lens provided by this invention achieves astigmatism correction while ensuring the same functionality in any radial direction by making the optical power distribution trends in two radial directions on the same diameter symmetrical about the geometric center and making the optical power distribution trends in radial directions corresponding to any two different angles the same. The overall optical performance of the lens is more accurate. Attached Figure Description
[0029] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0030] Figure 1 This is a schematic diagram illustrating the zero spherical aberration function achieved by a zero spherical aberration lens in the prior art provided by this utility model.
[0031] Figure 2 This is a diagram illustrating the different radial optical power distribution trends of an existing lens provided in the first embodiment of this utility model.
[0032] Figure 3 This is a schematic diagram of a three-dimensional coordinate system established based on the geometric center as the origin, provided in the first embodiment of this utility model.
[0033] Figure 4 This is a schematic diagram of the dot matrix distribution provided in the first embodiment of this utility model.
[0034] Figure 5 The first embodiment of this utility model provides a 3D surface map constructed using interpolation.
[0035] Figure 6 This is a schematic diagram of the rear surface curvature distribution provided in the first embodiment of this utility model.
[0036] Figure 7 This is the lens wavefront diagram provided in the first embodiment of this utility model.
[0037] Figure 8 This is a schematic diagram of the different radial optical power distribution trends provided in the first embodiment of this utility model.
[0038] Figure 9 This is a diagram illustrating the different radial optical power distribution trends of an existing lens provided in the second embodiment of this utility model.
[0039] Figure 10 This is a schematic diagram of a three-dimensional coordinate system established based on the geometric center as the origin, provided in the second embodiment of this utility model.
[0040] Figure 11 This is a schematic diagram of the dot matrix distribution provided in the second embodiment of this utility model.
[0041] Figure 12 The second embodiment of this utility model provides a 3D surface map constructed using interpolation.
[0042] Figure 13 This is a schematic diagram of the rear surface curvature distribution provided in the second embodiment of this utility model.
[0043] Figure 14 This is the lens wavefront diagram provided in the second embodiment of this utility model.
[0044] Figure 15 This is a schematic diagram of different radial optical power distribution trends provided in the second embodiment of this utility model.
[0045] Figure 16 This is a diagram illustrating the different radial optical power distribution trends of an existing lens provided in the third embodiment of this utility model.
[0046] Figure 17 This is a schematic diagram of a three-dimensional coordinate system established based on the geometric center as the origin, provided in the third embodiment of this utility model.
[0047] Figure 18 This is a schematic diagram of the dot matrix distribution provided in the third embodiment of this utility model.
[0048] Figure 19 The third embodiment of this utility model provides a 3D surface map constructed using interpolation.
[0049] Figure 20 This is a schematic diagram of the rear surface curvature distribution provided in the third embodiment of this utility model.
[0050] Figure 21 This is the lens wavefront diagram provided in the third embodiment of this utility model.
[0051] Figure 22 This is a schematic diagram of different radial optical power distribution trends provided in the third embodiment of this utility model.
[0052] Figure 23 This is a diagram illustrating the different radial optical power distribution trends of an existing lens provided in the fourth embodiment of this utility model.
[0053] Figure 24 This is a schematic diagram of a three-dimensional coordinate system established based on the geometric center as the origin, provided in the fourth embodiment of this utility model.
[0054] Figure 25 This is a schematic diagram of the dot matrix distribution provided in the fourth embodiment of this utility model.
[0055] Figure 26 This is the fourth embodiment of the present invention, which provides a 3D surface map constructed using interpolation.
[0056] Figure 27 This is a schematic diagram of the rear surface curvature distribution provided in the fourth embodiment of this utility model.
[0057] Figure 28 This is the lens wavefront diagram provided in the fourth embodiment of this utility model.
[0058] Figure 29 This is a schematic diagram of different radial optical power distribution trends provided in the fourth embodiment of this utility model. Detailed Implementation
[0059] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0060] In the description of the embodiments of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0061] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model based on the specific circumstances.
[0062] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0063] Before introducing toroidal lenses, the following related terms will be explained.
[0064] Toric surface: In the field of ophthalmic lenses, it generally refers to a surface containing at least two curvatures, with the directions of the maximum and minimum curvatures being perpendicular to each other. Toric surface lenses are mainly used for astigmatism correction in the human eye.
[0065] Radial: A straight line from the center of the lens along the radius or diameter.
[0066] Three-dimensional coordinate system: A three-dimensional coordinate system in which the X, Y, and Z axes are different from each other and perpendicular.
[0067] Radial distribution trend of optical power: The trend of the curve showing how the optical power of a lens changes with its radius.
[0068] Ra: Radius of curvature at the vertex of the front surface.
[0069] Rat: The radius of curvature of the vertex of the front surface perpendicular to Ra.
[0070] Rp: Radius of curvature at the vertex of the back surface.
[0071] Rpt: The vertex radius of curvature of the back surface perpendicular to Rp.
[0072] Qa: Aspheric coefficient of the front surface.
[0073] Qp: Back surface aspheric coefficient.
[0074] A4, ..., A16: Coefficients of even-order aspherical terms, whose expression on the aspherical curve along the Z-axis is given by the following formula:
[0075]
[0076] Where c is the curvature of the lens and r is the geometric radius of the lens.
[0077] When Q = A4 = ... = A16 = 0, the surface is a sphere. When A...2i If the surface is not equal to 0, for example, if at least one of A4, ... A16 is not zero, the surface is a higher-order aspherical surface.
[0078] The following is combined with Figures 2 to 29 This invention describes the specific structure and performance of the toric ophthalmic lens.
[0079] Toposcopic ophthalmic lenses are used to correct astigmatism in the human eye. The optical part of the lens has a geometric center. Within a circular or annular area centered on the geometric center, the optical power distribution trends on two radial directions on the same diameter are symmetrical about the geometric center, and the optical power distribution trends on the radial directions corresponding to any two different angles are the same.
[0080] The toric ophthalmic lens provided by this invention achieves astigmatism correction while ensuring the same functionality in any radial direction by making the optical power distribution trends in two radial directions on the same diameter symmetrical about the geometric center and making the optical power distribution trends in radial directions corresponding to any two different angles the same. The overall optical performance of the lens is more accurate.
[0081] It should be noted that toroidal ophthalmic lenses include, but are not limited to, external eyeglasses, contact lenses, intraocular lenses (phakic and aphakic).
[0082] In one embodiment of the present invention, at least one surface of the optical part satisfies the following: with the geometric center of the surface as the origin {0, 0, 0}, that is, the origin O of the three-dimensional coordinate system is established, the plane {X, Y, 0} is tangent to the geometric center, and a three-dimensional coordinate system is 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);
[0083] (1)
[0084] Among them, h f (x, y) is the optical curve distribution function along 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).
[0085] h s (x, y) and h f The surface design along the radial direction (x, y) is related to the intended function of the lens, which includes aberration control, slowing myopia progression, extending depth of field, and precise matching with other structures. The optical surface of the lens cannot be described by a spherical arc.
[0086] While ensuring hs (x, y) and h f When the optical power distribution trend in the radial direction of (x, y) is the same, the sag at any position on the lens surface can be calculated using formula (1). This ensures that the optical power distribution trend in any radial direction of the toric ophthalmic lens is exactly the same, thus achieving precision and consistency of optical functionality in all directions.
[0087] In one embodiment of the present invention, at least one surface of the optical part of the toric ophthalmic lens has an optical curvature shape along any radial direction passing through the geometric center as a non-single curvature spherical arc.
[0088] In one embodiment of this utility model, the diameter of the optical part is D, then x, y and D satisfy the following formula (2);
[0089] (2)
[0090] It should be noted here that (x, y) is a point in the |X,Y,Z| lattice.
[0091] In one embodiment of this utility model, h s (x, y) and h f (x, y) are all even-order aspherical curves, odd-order aspherical curves, cubic spline curves, or free curves. Preferably, h s (x, y) and h f (x, y) are both even-order aspherical curves.
[0092] In one embodiment of this utility model, in h s (x, y) and h f When (x, y) are both even-order aspherical curves, the aspherical coefficient Q and the coefficients of even-order aspherical higher-order terms are not completely the same in any radial direction. That is, the aspherical coefficient Q is not completely the same in any radial direction, and the coefficients of even-order aspherical higher-order terms A4, ... A16 are not completely the same either.
[0093] In one embodiment of this invention, any radial direction of the surface is an aspherical arc and has at least two curvatures.
[0094] In one embodiment of this utility model, the surface has a radial spherical arc with one curvature; the remaining radial arcs are all aspherical arcs with at least two curvatures.
[0095] In one embodiment of this utility model, within a circle centered at the geometric center, the optical power of any radial radius r satisfies the following formula (3).
[0096] φ(r)=φ(-r) (3)
[0097] Where r∈(0, It should be noted here that φ(r) is the optical power in the radial direction of radius r, and φ(-r) is the optical power in the radial direction of the radius that is symmetrical to radius r about the geometric center.
[0098] In one embodiment of this utility model, the radial optical power distribution trend corresponding to any two angles θ1 and θ2 The following formula (4) must be satisfied;
[0099] = (4)
[0100] in, θ 1 ∈[0°,360°), θ 2 ∈[0°,360°) ,and θ 1 ≠θ 2 .
[0101] In one embodiment of this invention, the lens includes an external eyeglass frame, the diameter of which is 40-80 mm. Preferably, the diameter of which is 60-80 mm.
[0102] In one embodiment of this invention, the lens includes a contact lens, which is a corneal contact lens or a scleral contact lens, and the diameters of the optical parts of both the corneal and scleral contact lenses are 7-12 mm. Preferably, the diameters of both the corneal and scleral contact lens optical parts are 8-10 mm.
[0103] In one embodiment of this invention, the lens includes an intraocular lens with a phakic lens, and the diameter of the optical portion of the intraocular lens is 4-8 mm. Preferably, the diameter of the optical portion of the intraocular lens is 4.5-6.5 mm.
[0104] In one embodiment of this invention, the lens includes an aphakic intraocular lens, the diameter of which is 4-8 mm. Preferably, the diameter of which is 5-6.5 mm.
[0105] This utility model also provides a method for calculating the surface curvature of a toric ophthalmic lens. The method is used to calculate the surface curvature of the toric ophthalmic lens described in any of the above embodiments. The method for calculating the surface curvature of the toric ophthalmic lens includes:
[0106] Step S100: Determine the surface of the lens and the dimensional parameters of the lens;
[0107] Step S200: Establish a three-dimensional coordinate system with the geometric center of the surface as the origin;
[0108] Step S300: Calculate the optical curve distribution function h in the X-axis direction. s (x,y) and the optical curve distribution function h along the Y-axis. f (x,y);
[0109] Step S400: Calculate any point {x, y, Z(x, y)} on the surface to obtain the |X, Y, Z| lattice;
[0110] Step S500: Obtain the surface shape using interpolation based on the |X, Y, Z| lattice.
[0111] In one embodiment of this invention, the three-dimensional coordinate system has its origin {0, 0, 0} at the geometric center of the surface, and the {X, Y, 0} plane is tangent to the geometric center. The average optical power of the lens is used as the reference value. φ The smallest direction is the X-axis.
[0112] In one embodiment of this utility model, h s The optical power distribution trend along the radial direction of (x,y) is related to h f The optical power distribution trend is the same along the radial direction of (x,y), that is... .
[0113] In one embodiment of this utility model, the interpolation method includes spline interpolation, polynomial interpolation, or least squares interpolation.
[0114] The following is combined with Figures 2 to 8 The first specific embodiment of this utility model is described, such as Figures 2 to 8 As shown, in this embodiment, the lens is an extended depth-of-field (EDF) astigmatism-correcting intraocular lens with a diameter of 6.0 mm, a vertex spherical power of +10.0 D, and a cylindrical power of +4.5 D.
[0115] Existing lenses typically feature a rotationally symmetric high-order aspherical design on the front and rear surfaces to extend the depth of field, while the other surface is a complex toroidal combined with a spherical design to correct astigmatism, as shown in Table 1 below. The radial power distribution trends of such lenses differ, for example... Figure 2 As shown.
[0116] Table 1
[0117]
[0118] To solve the above problems, the surface calculation method of the toric ophthalmic lens of this invention is used to calculate the surface of the lens. The surface calculation method of the toric ophthalmic lens includes:
[0119] Step S100: Select the rear surface of the lens, with the diameter of the optical part being 5.0 mm;
[0120] Step S200: Establish a three-dimensional coordinate system with the geometric center of the surface as the origin;
[0121] With the geometric center of the rear surface as the origin O = {0, 0, 0}, and the {X, Y, 0} plane tangent to the geometric center, a three-dimensional XYZ coordinate system is established. The radial direction with an optical power of +10.0D (rear surface curvature radius of -11.15mm) is the direction of minimum average optical power, and this is taken as the X-axis. The radial direction with an optical power of +14.5D (rear surface curvature radius of -6.25mm) is the Y-axis. Figure 3 As 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 along the Y-axis. f (x,y);
[0123] The formula for calculating the optical surface shape h in the direction with the minimum average optical power (vertex optical power of +10.0D, radius of curvature of -11.15mm) is given. f The optical curve distribution function h in the direction perpendicular to (x, y) and in the direction perpendicular to it (vertex power +14.5D, radius of curvature -6.25mm). s (x,y), where h s (x,y) and h f (x,y) should make the overall optical power distribution trend of the lens in the direction of minimum average optical power and in the direction perpendicular to it exactly the same. The following formula (5) is used for calculation.
[0124] (5)
[0125] Step S400: Calculate any point {x, y, Z(x, y)} on the surface to obtain the |X, Y, Z| lattice;
[0126] Based on formulas (5) and (1), any point {x, y, Z(x, y)} on the surface is calculated, and a |X, Y, Z| lattice is formed with an interval of 0.05 mm, as shown below. Figure 4 As shown.
[0127] Step S500: Construct a 3D surface map using bicubic spline interpolation based on the |X, Y, Z| lattice.
[0128] like Figure 5As shown, the lens constructed according to the above steps has a front surface that is a high-order aspherical surface and a rear surface that is the curved surface described in this invention. The rear surface is a single-curvature spherical arc only in the radial direction along the X-axis, with a curvature of -0.08968 mm. -1 In all other directions, the surface is an aspherical arc with at least two types of curvature.
[0129] Back surface curvature distribution as shown Figure 6 As shown, the lens wavefront diagram is as follows Figure 7 As shown, the radial optical 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 optical power distribution trends in each radial direction are exactly the same. While achieving astigmatism correction, it ensures the same functionality in any radial direction, guarantees consistent depth-of-field extension effects in different directions, and improves the accuracy of lens function.
[0130] The following is combined with Figures 9 to 15 The second specific embodiment of this utility model is described below, as follows: Figures 9 to 15 As shown, in this embodiment, the lens is a zero-spherical-aberration astigmatism-correcting phakic intraocular lens with a spherical power of -20.0D and a cylindrical power of -5D. Existing lenses typically feature a front / rear surface design with rotationally symmetric high-order aspherical surfaces to achieve zero spherical aberration, while the other surface is a complex toric surface combined with a spherical surface design to achieve astigmatism correction, as shown in Table 2 below. The radial power distribution trends of the lens vary, such as... Figure 9 As shown.
[0131] Table 2
[0132]
[0133] To solve the above problems, the surface calculation method of the toric ophthalmic lens of this invention is used to calculate the surface of the lens. The surface calculation method of the toric ophthalmic lens includes:
[0134] Step S100: Select the rear surface of the lens, with the diameter of the optical part being 6.0 mm;
[0135] Step S200: Establish a three-dimensional coordinate system with the geometric center of the surface as the origin;
[0136] With the geometric center of the surface as the origin O = {0, 0, 0}, and the {X, Y, 0} plane tangent to the geometric center, a three-dimensional XYZ coordinate system is established. The radial direction with an optical power of -25.0D (front surface curvature radius of -8.37mm) is the direction of minimum average optical power, and this is taken as the X-axis. The radial direction with an optical power of -20.0D (front surface curvature radius of -15.04mm) is the Y-axis. Figure 10 As shown.
[0137] Step S300: Calculate the optical curve distribution function h in the X-axis direction. s (x,y) and the optical curve distribution function h along the Y-axis. f (x,y);
[0138] The formula for calculating the optical surface shape h in the direction with the minimum average optical power (vertex optical power of -25.0D, radius of curvature of -8.37mm) is given. f The optical curve distribution function h in the direction perpendicular to (x, y) and in the direction perpendicular to it (vertex optical power of -20.0D, radius of curvature of -15.04mm). s (x,y), where h s (x,y) and h f (x,y) should make the overall optical power distribution trend of the lens in the direction of minimum average optical power and in the direction perpendicular to it exactly the same. The following formula (6) is used for calculation.
[0139] (6).
[0140] Step S400: Calculate any point {x, y, Z(x, y)} on the surface to obtain the |X, Y, Z| lattice;
[0141] Based on formulas (6) and (1), any point {x, y, Z(x, y)} on the surface is calculated, and a |X, Y, Z| lattice is formed with an interval of 0.1 mm, as shown below. Figure 11 As shown.
[0142] Step S500: Construct a 3D surface map using bicubic spline interpolation based on the |X, Y, Z| lattice.
[0143] like Figure 12 As shown, the lens constructed according to the above steps has a front surface that is a combination of a toroidal and spherical surface, and a rear surface that is the curved surface described in this invention. The rear surface has an aspherical arc in any radial direction, possessing at least two curvatures.
[0144] Back surface curvature distribution as shown Figure 13 As shown, the lens wavefront diagram is as follows Figure 14 As shown, the radial optical power distribution trends at 0° (X-axis direction), 90° (Y-axis direction), and 30°, 45°, and 60° are as follows: Figure 15 As shown, the optical power distribution trends in each radial direction are exactly the same. While achieving astigmatism correction, it ensures the same functionality in any radial direction, guarantees consistent depth-of-field extension effects in different directions, and improves the accuracy of lens function.
[0145] The following is combined with Figures 16 to 22 The third specific embodiment of this utility model is described below, as follows: Figures 16 to 22As shown, in this embodiment, the lens is a progressive focal length contact lens used to slow the progression of myopia. The diameter of the optical part is 8.0 mm, the vertex spherical power is -6.0D, and the cylindrical power is -4.0D. Existing lenses generally have a front surface that is a rotationally symmetrical aspherical design with one or more segments to achieve the progressive focal length optical zone, and another surface that is a complex surface combined with a spherical surface or a complex surface combined with an aspherical surface with the same coefficient (Q) to achieve astigmatism correction, as shown in Table 3 below. The radial power distribution trends of the lens differ, such as... Figure 16 As shown.
[0146] Table 3
[0147]
[0148] To solve the above problems, the surface calculation method of the toric ophthalmic lens of this invention is used to calculate the surface of the lens. The surface calculation method of the toric ophthalmic lens includes:
[0149] Step S100: Select the rear surface of the lens, with the diameter of the optical part being 8.0 mm;
[0150] Step S200: Establish a three-dimensional coordinate system with the geometric center of the surface as the origin;
[0151] With the geometric center of the rear surface as the origin O = {0, 0, 0}, and the {X, Y, 0} plane tangent to the geometric center, a three-dimensional XYZ coordinate system is established. The radial direction with an optical power of -10.0D (rear surface curvature radius of 8.49mm) is the direction of minimum average optical power, and this is taken as the X-axis. The radial direction with an optical power of -6.0D (rear surface curvature radius of 9.00mm) is the Y-axis. Figure 17 As shown.
[0152] Step S300: Calculate the optical curve distribution function h in the X-axis direction. s (x,y) and the optical curve distribution function h along the Y-axis. f (x,y);
[0153] The formula for calculating the optical surface shape h in the direction with the minimum average optical power (vertex optical power of -10.0D, radius of curvature of 8.49mm) is given. f The optical curve distribution function h in the direction perpendicular to (x,y) and perpendicular to it (vertex power -6.0D, radius of curvature 9.00mm). s (x,y), where h s (x,y) and h f (x,y) should make the overall optical power distribution trend of the lens in the direction of minimum average optical power and in the direction perpendicular to it exactly the same. The following formula (7) is used for calculation.
[0154] (7)
[0155] Step S400: Calculate any point {x, y, Z(x, y)} on the surface to obtain the |X, Y, Z| lattice;
[0156] Based on formulas (7) and (1), any point {x, y, Z(x, y)} on the surface is calculated, and a |X, Y, Z| lattice is formed with an interval of 0.2 mm, as shown below. Figure 18 As shown.
[0157] Step S500: Construct a 3D surface map using bicubic spline interpolation based on the |X, Y, Z| lattice.
[0158] like Figure 19 As shown, the lens constructed according to the above steps has a front surface that is a high-order aspherical surface and a rear surface that is the curved surface described in this invention. The rear surface has an aspherical arc in any radial direction, possessing at least two curvatures.
[0159] Back surface curvature distribution as shown Figure 20 As shown, the lens wavefront diagram is as follows Figure 21 As shown, the radial optical power distribution trends at 0° (X-axis direction), 90° (Y-axis direction), and 30°, 45°, and 60° are as follows: Figure 22 As shown, the distribution trend of optical power in each radial direction is exactly the same, which ensures that the defocus amount in different directions is the same while achieving astigmatism correction, thus improving the accuracy of the lens function.
[0160] The following is combined with Figures 23 to 29 The fourth specific embodiment of this utility model is described, as follows: Figures 23 to 29 As shown, in this embodiment, the lens is a progressive optical lens for relieving eye strain. The diameter of the optical part is 70.0 mm, the vertex spherical power is -2.0D, and the cylindrical power is -0.5D. Existing lenses generally have a front surface designed as an aspherical surface with rotational symmetry under one or more aspherical formulas to achieve a progressive optical zone, and another surface designed as a complex surface combined with a spherical surface or a complex surface combined with an aspherical surface with the same aspherical coefficient (Q) to achieve astigmatism correction. Alternatively, the front and rear surfaces may be a torus surface design defined by a set of high-order aspherical formulas, as shown in Table 4 below. The radial power distribution trends of the lens differ, such as... Figure 23 As shown.
[0161] Table 4
[0162]
[0163] To solve the above problems, the surface calculation method of the toric ophthalmic lens of this invention is used to calculate the surface of the lens. The surface calculation method of the toric ophthalmic lens includes:
[0164] Step S100: Select the front surface of the lens, with the optical part being a ring with an inner diameter of 2.0 mm and an outer diameter of 70 mm;
[0165] Step S200: Establish a three-dimensional coordinate system with the geometric center of the surface as the origin;
[0166] With the geometric center of the surface as the origin O = {0, 0, 0}, and the {X, Y, 0} plane tangent to the geometric center, a three-dimensional XYZ coordinate system is established. The radial direction with an optical power of -2.5D (front surface curvature radius of 86.28mm) is the direction of minimum average optical power, and this is taken as the X-axis. The radial direction with an optical power of -2.0D (front surface curvature radius of 79.50mm) is the Y-axis. Figure 24 As shown.
[0167] Step S300: Calculate the optical curve distribution function h in the X-axis direction. s (x,y) and the optical curve distribution function h along the Y-axis. f (x,y);
[0168] The formula for calculating the optical surface shape h in the direction with the minimum average optical power (vertex optical power of -2.5D, radius of curvature of 86.28mm) is given. f The optical curve distribution function h in the direction perpendicular to (x, y) and in the direction perpendicular to it (vertex power of -2.0D, radius of curvature of 79.50mm). s (x,y), where h s (x,y) and h f (x,y) should make the overall optical power distribution trend of the lens in the direction of minimum average optical power and in the direction perpendicular to it exactly the same. The following formula (8) is used for calculation.
[0169] (8).
[0170] Step S400: Calculate any point {x, y, Z(x, y)} on the surface to obtain the |X, Y, Z| lattice;
[0171] Based on formulas (8) and (1), any point {x, y, Z(x, y)} on the surface is calculated, and a |X, Y, Z| lattice is formed with an interval of 0.5 mm, as shown below. Figure 25 As shown.
[0172] Step S500: Construct a 3D surface map using bicubic spline interpolation based on the |X, Y, Z| lattice.
[0173] like Figure 26As shown, the lens constructed according to the above steps has a spherical rear surface and a curved front surface as described in this invention. The front surface is a combination of a complex curved surface and a higher-order aspherical surface. The radial aspherical coefficient Q and the even-order aspherical higher-order coefficients A4, A6, and A8 are not completely identical. Specifically, the even-order aspherical higher-order coefficient A8 is the same at 0° (X-axis direction) and 90° (Y-axis direction), while the aspherical coefficient Q and the even-order aspherical higher-order coefficients A4 and A6 are different. The front surface is an aspherical arc in any radial direction, possessing at least two curvatures.
[0174] Back surface curvature distribution as shown Figure 27 As shown, the lens wavefront diagram is as follows Figure 28 As shown, the radial optical power distribution trends at 0° (X-axis direction), 90° (Y-axis direction), and 30°, 45°, and 60° are as follows: Figure 29 As shown, the distribution trend of optical power in each radial direction is exactly the same, which ensures that the defocus amount in different directions is the same while achieving astigmatism correction, thus improving the accuracy of the lens function.
[0175] The method for calculating the curvature of toric ophthalmic lenses provided by this invention is also applicable to the positioning of toric surfaces of ophthalmic lenses, such as the positioning calculation of the inner surface of corneal contact lenses (the surface in contact with the human eye) and the calculation of the positioning arc of orthokeratology lenses. It is particularly suitable for calculating the toric surfaces of lenses with different eccentricities in the flat and steep directions of the cornea.
[0176] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.
Claims
1. A toric ophthalmic lens for correcting astigmatism in the human eye; characterized in that, The optical part of the lens has a geometric center. Within a circular or annular area centered on the geometric center, the optical power distribution trends of two radial directions on the same diameter are symmetrical about the geometric center, and the optical power distribution trends of radial directions corresponding to any two different angles are the same.
2. The toric ophthalmic lens according to claim 1, characterized in that, At least one surface of the optical part satisfies the following: with the geometric center of the surface as the origin {0, 0, 0}, the plane {X, Y, 0} is tangent to the geometric center, and a three-dimensional coordinate system is 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 along 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, characterized in that, If 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, characterized in that, The h s (x, y) and the h f (x, y) are all even-order aspherical curves, odd-order aspherical curves, cubic spline curves, or free curves.
5. The toric ophthalmic lens according to claim 4, characterized in that, In the h s (x, y) and the h f When (x, y) are both even-order aspherical curves, the aspherical coefficient Q on any radial direction and the coefficient of the higher-order even-order aspherical term are not completely the same.
6. The toric ophthalmic lens according to any one of claims 2 to 5, characterized in that, The surface has an arbitrary radial direction that 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 one radially spherical arc with one curvature; the remaining radially are all aspherical arcs with at least two curvatures.
8. The toric ophthalmic lens according to any one of claims 1 to 5, characterized in that, Within a circle centered at the geometric center, the optical power of any radial radius r satisfies the following formula (3); φ(r)=φ(-r) (3) Where r∈(0, ] .
9. The toric ophthalmic lens according to any one of claims 1 to 5, characterized in that, The radial optical power distribution trend corresponding to any two angles θ1 and θ2 The following formula (4) must be satisfied; = （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 an external eyeglass frame, wherein the diameter of the optical part of the external eyeglass frame 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, and the diameter of the optical part of the corneal contact lens and the optical part of the scleral contact lens are both 7~12mm.
12. The toric ophthalmic lens according to any one of claims 1 to 5, characterized in that, The lens includes an intraocular phakic intraocular lens, and the diameter of the optical part of the intraocular phakic intraocular lens is 4~8mm.
13. The toric ophthalmic lens according to any one of claims 1 to 5, characterized in that, The lens includes an aphakic intraocular lens, and the diameter of the optical part of the aphakic intraocular lens is 4-8 mm.