Toric intraocular lens and method for designing toric intraocular lens

Abstract

The present application relates to a toric intraocular lens comprising an optical portion having an anterior optical surface and a posterior optical surface and a haptic supporting the optical portion, at least one of the anterior optical surface and the posterior optical surface being a toric surface, the method comprises the following steps: firstly setting a group of initial values of a shape factor of an optical part, then calculating the focal power of an optical surface according to target equivalent spherical power and the initial values, calculating the curvature radius of a toric surface according to the obtained focal power and target cylindrical power, and then judging whether the obtained toric surface meets the imaging quality requirement or not through a modulation transfer function. If the imaging quality requirement is met, the corresponding shape factor value is selected, and if the imaging quality requirement is not met, the shape factor value is reset, and the previous steps are repeated. The invention further provides a method for designing the toric intraocular lens.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of intraocular lenses, and in particular to a toric intraocular lens and a method of designing the same. BACKGROUND

[0002] The background description provided herein is for the purpose of generally presenting the context of the application. The work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description in this section that are not specifically and clearly articulated as being prior art, are neither expressly nor impliedly admitted as prior art against the present application.

[0003] An intraocular lens is an artificial lens implanted in the eye to replace the natural lens of the eye, to restore vision. According to the different implantation positions of the intraocular lens, the intraocular lens has an anterior chamber type, a posterior chamber type, and a ciliary groove implantation type. According to the different materials made, the intraocular lens is divided into PMMA, silicone, hydrogel, and acrylate materials. The intraocular lens in the present application refers to a foldable intraocular lens made of the above-mentioned materials, which is referred to as an intraocular lens.

[0004] Astigmatism is a state of ocular refractive error. The cause of astigmatism is that the curvature of the cornea or the lens surface is inconsistent, such as an olive ball shape, which causes the refractive power of two meridians perpendicular to each other to be different and unable to focus on a point, forming an unclear or overlapping image. The spherical aberration of the cornea and its higher-order aberrations as another aberration affecting visual quality have a significant impact on the visual quality after cataract surgery. With the increase of age, cataract and astigmatism can occur at the same time. If a person with corneal astigmatism implants a single-focus aspheric intraocular lens, although the cataract problem is solved, the patient will still be affected by astigmatism and have poor vision, and cannot be taken off the glasses. Therefore, an astigmatism correcting intraocular lens is needed to solve the problems of cataract and astigmatism at the same time. SUMMARY

[0005] This section introduces the selection of the inventive concept in a simplified form, which will be further embodied in the detailed description below. This section is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in determining the scope of the claimed subject matter.

[0006] The above-mentioned features and advantages of the present application and other features and advantages will become apparent from the following detailed description of preferred embodiments and best modes for carrying out the present application, taken in conjunction with the accompanying drawings and the appended claims.

[0007] In one aspect of the present application, a toric intraocular lens is provided, the toric intraocular lens comprising an optical portion having an anterior optical surface and a posterior optical surface, and a haptic supporting the optical portion, characterized in that at least one of the anterior optical surface and the posterior optical surface is a toric surface, the toric surface being designed according to the following steps:

[0008] i) setting a set of initial values of a shape factor of the optical portion, the set of initial values comprising a plurality of numerical values;

[0009] ii) calculating, for each numerical value of the set of initial values, a power of the anterior optical surface and a power of the posterior optical surface according to a target equivalent sphere of the intraocular lens and the numerical value, wherein, PAN is the power of the anterior optical surface and PPO is the power of the posterior optical surface, SE is the target equivalent sphere, and SF is the shape factor;

[0010] iii) calculating, according to the target cylinder CYL of the intraocular lens, the power of the anterior optical surface and the power of the posterior optical surface, a radius of curvature of the toric surface;

[0011] iv) calculating a value of a modulation transfer function of the intraocular lens according to the obtained toric surface, and determining whether an imaging quality of the intraocular lens is satisfied based on the calculated value of the modulation transfer function;

[0012] v) if the imaging quality is satisfied, selecting the numerical value of the shape factor as a desired value of the shape factor to design the intraocular lens, or setting again a set of initial values comprising the desired value of the shape factor and repeating steps ii) to iv) to select a shape factor with a better imaging quality; if the imaging quality is not satisfied, repeating steps i) to iv).

[0013] Preferably, one of the anterior optical surface and the posterior optical surface is a toric surface, wherein the toric surface is expressed as: wherein R iy is a radius of curvature in a meridian direction of the toric surface being the anterior optical surface and the posterior optical surface, R ix is a radius of curvature perpendicular to the meridian direction, and i = 1 or 2.

[0014] Preferably, the method further comprises a step of designing the other one of the anterior optical surface and the posterior optical surface as an aspherical surface, wherein the aspherical surface is characterized by: and wherein y, z are y-axis coordinate and z-axis coordinate of the aspherical surface, c is a curvature, k is a conic coefficient, and a2, a4, a6 are aspherical coefficients.

[0015] Preferably, both of the anterior optical surface and the posterior optical surface are toric surfaces, wherein the toric surfaces are expressed as: where i = 1 or 2, R iy R is the radius of curvature in a certain meridional direction of the toric surface that is either the front optical surface or the back optical surface, R ix R is the radius of curvature perpendicular to this meridional direction, and where, CYL1 is the cylinder of the front optical surface, CYL2 is the cylinder of the back optical surface, SF2 is the second shape factor.

[0016] Preferably, the method further comprises the step of designing an aspherical surface on the front optical surface and / or on the back optical surface, the aspherical surface being characterized by: where the vertex of the surface is the origin of coordinates O, the optical axis is the z axis, the sagittal plane is in the plane xOz, the meridional plane is in the plane yOz, and Cx, Cy represent respectively the curvature of the intraocular lens at the vertex in the sagittal and meridional planes, Kx and Ky represent respectively the quadratic surface coefficients of the intraocular lens in the sagittal and meridional planes, A i and B j are higher order aspherical coefficients, i and j are natural numbers greater than or equal to 0, x is the sagittal direction coordinate, y is the meridional direction coordinate.

[0017] Preferably, the value of the shape factor is between 0 and 0.7.

[0018] Preferably, the value of the shape factor is between 0 and 0.5.

[0019] Preferably, the value of the shape factor is between 0 and 0.2.

[0020] Preferably, the value of the shape factor is between 0 and 0.1.

[0021] Preferably, the value of the second shape factor is 0.6.

[0022] Preferably, the equivalent sphere of the intraocular lens is between 0 D and 42 D, and the cylinder is between 0.5 D and 10 D.

[0023] Preferably, the spherical aberration of the intraocular lens is between -0.3 pm and 0.05 pm.

[0024] In another aspect of the application, there is also provided a method of designing a toric intraocular lens comprising an optical portion having a front optical surface and a back optical surface, and a haptic supporting the optical portion, characterized in that at least one of the front optical surface and the back optical surface is toric, the toric surface being designed according to the following steps:

[0025] i) setting a set of initial values of a shape factor of the optical portion, the set of initial values comprising a plurality of numerical values;

[0026] ii) calculating the power of the anterior optical surface and the power of the posterior optical surface according to the target equivalent sphere of the intraocular lens and each value in the set of initial values, wherein, is the power of the anterior optical surface and is the power of the posterior optical surface, SE is the target equivalent sphere, and SF is the shape factor;

[0027] iii) calculating the radius of curvature of the toric surface according to the target cylinder CYL of the intraocular lens, the power of the anterior optical surface and the power of the posterior optical surface;

[0028] iv) calculating the value of the modulation transfer function of the intraocular lens according to the obtained toric surface, and judging whether the imaging quality of the intraocular lens is satisfied based on the calculated value of the modulation transfer function;

[0029] v) if the imaging quality is satisfied, selecting the value of the corresponding shape factor as the expected value of the shape factor to design the intraocular lens, or setting again a set of initial values containing the expected value of the shape factor, repeating steps ii)-iv) to select a shape factor with better imaging quality to design the intraocular lens; if the imaging quality is not satisfied, repeating steps i)-iv). BRIEF DESCRIPTION OF DRAWINGS

[0030] Other or additional features, advantages, and characteristics of the embodiments are presented in the following detailed description of the embodiments. In the drawings:

[0031] Figure 1 A schematic diagram of an intraocular lens according to the principles of the present application is shown;

[0032] Figure 2 An MTF diagram of an intraocular lens with the optical anterior surface being a toric surface is shown;

[0033] Figure 3 A preferred MTF diagram of an intraocular lens with the optical anterior surface being a toric surface is shown;

[0034] Figure 4 An MTF diagram of an intraocular lens with both the optical anterior and posterior surfaces being toric surfaces is shown;

[0035] Figure 5 A MTF diagram of an intraocular lens with both the optical anterior and posterior surfaces being toric surfaces after optimized design is shown;

[0036] Figure 6 A comparison diagram of MTFs of an intraocular lens with only one optical surface being a toric surface and both surfaces being toric surfaces is shown. DETAILED DESCRIPTION

[0037] The following description is exemplary in nature and is not intended to limit this application, application, or use. Furthermore, it is not intended to be limited by any express or implied theory presented in the foregoing technical field, background art, summary of the invention, or the following detailed description. It should be understood that throughout the drawings, corresponding reference numerals identify similar or corresponding parts or features.

[0038] This application will now be further elaborated. In the following paragraphs, different aspects of this application are defined in more detail. Unless expressly indicated to the contrary, each aspect so defined may be combined with any other aspect(s). In particular, any feature indicated as preferred or advantageous may be combined with any other feature(s) indicated as preferred or advantageous.

[0039] One aspect of this application discloses an intraocular lens with a tortuous surface. (See attached document.) Figure 1 This invention illustrates an astigmatism-correcting intraocular lens (Toric IOL) according to the principles of this application, comprising an optical portion 1 and a support haptic portion 2. The optical portion 1 includes an edge 5, and the support haptic portion 2 is connected to the edge 5. The support haptic portion 2 serves to support the optical portion 1 after implantation into the capsular bag. The optical portion 1 and the support haptic portion 2 are made of the same material. The optical portion 1 includes an anterior optical surface 3 and a posterior optical surface 4, which are used to generate different optical powers. The diameter of the optical portion is the optical diameter, and the diameter of the circumcircle 6 of the support haptic portion 2 is the total diameter of the intraocular lens. The optical portion 1 has an axis marking line 7 to indicate the meridional plane of minimum refractive power of the intraocular lens.

[0040] This application achieves excellent image quality by designing the anterior optical surface 3 and the posterior optical surface 4 as toric and / or aspherical surfaces, enabling the intraocular lens (IOL) to correct astigmatism while compensating for corneal spherical aberration. Advantageously, the IOL of this application is a toric IOL, wherein at least one of the anterior and posterior optical surfaces is toric to correct astigmatism. Advantageously, the equivalent spherical power of the IOL's optical portion is 0D to 42D, and the cylindrical power is 0.5D to 10D, allowing the IOL to meet the needs of most patients. Advantageously, the spherical aberration of the IOL is between -0.3μm and 0.05μm, enabling the IOL to provide clear image quality within a 5.0mm aperture while offering varying degrees of depth of focus.

[0041] It is readily understood by those skilled in the art:

[0042]

[0043] Cylindrical power CYL = Steep axis spherical power - Flat axis spherical power

[0044]

[0045] wherein, respectively represent the optical power in two meridional planes of the intraocular lens, respectively represent the optical power in two meridional planes of the anterior optical surface of the intraocular lens, respectively represent the optical power in two meridional planes of the posterior optical surface of the intraocular lens, n iol represents the refractive index of the intraocular lens, n medium represents the refractive index of the medium environment, r represents the radius of curvature of the optical surface.

[0046] By the above formula, the radius of curvature of the optical surface of the intraocular lens can be derived, and the shape factor SF of the intraocular lens can be represented by the following formula:

[0047]

[0048] wherein, R1 is the radius of curvature of the anterior optical surface, and R2 is the radius of curvature of the posterior optical surface.

[0049] The shape factor SF is represented by the optical power , then it can be represented as:

[0050]

[0051] wherein, is the optical power of the anterior optical surface, is the optical power of the posterior optical surface,

[0052] Further derivation, the and are represented by the equivalent spherical power SE and the shape factor SF, then:

[0053]

[0054] It can be seen that according to the value of the shape factor SF and the value of the equivalent spherical power SE, the optical power of the anterior optical surface of the intraocular lens and the optical power of the posterior optical surface of the intraocular lens Further, the radius of curvature of the toric surface of the intraocular lens can be calculated according to the optical power and the cylinder power CYL by the following formula:

[0055]

[0056] wherein, R iy is the radius of curvature in a meridional plane direction of the toric surface as the anterior optical surface or the posterior optical surface, R ix is the radius of curvature perpendicular to the meridional plane direction, i=1 or 2, and Δn is the difference between the refractive index of the intraocular lens and the refractive index of the medium environment.

[0057] As is well understood by those skilled in the art, when designing the surface shape of the intraocular lens, the equivalent spherical power SE and the cylindrical power CYL are known as design indicators, and thus, when the shape factor SF is determined, the power of the anterior optical surface of the intraocular lens can be calculated according to the shape factor SF and the equivalent spherical power SE and the power of the posterior optical surface of the intraocular lens and the radius of curvature of the toric surface can be calculated according to the power and the cylindrical power.

[0058] Based on the above, when the anterior optical surface of the intraocular lens according to the principles of the present application is a toric surface, the toric surface can be expressed as:

[0059]

[0060] When the posterior optical surface of the intraocular lens is a toric surface, the toric surface can be expressed as:

[0061]

[0062] wherein R 1y is the radius of curvature in the meridional direction of the toric surface on the anterior optical surface with the minimum power, R 1x is the radius of curvature perpendicular to the meridional direction, i.e. the radius of curvature in the meridional direction with the maximum power; R 2y is the radius of curvature in the meridional direction of the toric surface on the posterior optical surface with the minimum power, and R 2x is the radius of curvature perpendicular to the meridional direction, i.e. the radius of curvature in the meridional direction with the maximum power.

[0063] Advantageously, when one of the anterior optical surface and the posterior optical surface of the intraocular lens is a toric surface, the other can be a spherical surface or an aspherical surface, and when it is an aspherical surface, the aspherical surface can be expressed as:

[0064]

[0065] wherein y and z are the y-axis coordinate and the z-axis coordinate of the aspherical surface in the yOz rectangular coordinate system, c is the curvature, k is the conic coefficient, and a2, a4, a6 are the aspherical coefficients. As is well understood by those skilled in the art, the design of the aspherical surface will reduce the spherical aberration and its higher-order aberration, further improving the imaging quality.

[0066] Advantageously, both the anterior optical surface and the posterior optical surface of the intraocular lens can be provided as toric surfaces, and in this case, a second shape factor SF2 can be introduced, which is mainly used to represent the distribution of the cylindrical power, and the second shape factor SF2 can be expressed as:

[0067]

[0068] wherein CYL1 is the cylinder of the anterior optical surface and CYL2 is the cylinder of the posterior optical surface. Thus, CYL1 and CYL2 can be expressed as follows:

[0069]

[0070] Further, the anterior optical surface of the intraocular lens can be expressed as:

[0071]

[0072] The posterior optical surface can be expressed as:

[0073]

[0074] Advantageously, when both the anterior and posterior surfaces of the intraocular lens are toric, the asphericity can be performed on at least one of the anterior and posterior optical surfaces, and the asphericity can be expressed in the rectangular coordinate system as:

[0075]

[0076] wherein the vertex of the toric surface is the coordinate origin O of the rectangular coordinate system, the optical axis is the z-axis, the sagittal plane is in the plane xOz, the meridional plane is in the plane yOz, Z represents the sagittal height of the toric surface, and Cx, Cy represent the curvature of the vertex of the intraocular lens in the sagittal plane and the meridional plane, respectively, K x and K y represent the quadratic surface coefficients of the intraocular lens in the sagittal plane and the meridional plane, respectively, A i and B j are high-order asphericity coefficients, i and j are natural numbers greater than or equal to 0, x is the sagittal direction coordinate, and y is the meridional direction coordinate.

[0077] According to the above, in the design of the toric intraocular lens, different shape factors SF can be randomly set according to the principle of the Monte Carlo method, and combined with the design indicators such as the equivalent spherical power SE and the cylinder CYL, different toric intraocular lens surface shapes can be designed, and the imaging quality of different surface shapes can be verified, for example, the imaging quality of the surface shape is verified by a simulation experiment of the modulation transfer function (MTF), and the surface shape with excellent imaging quality is selected according to the verification result. Therefore, the present application discloses a method for designing a toric intraocular lens, the toric intraocular lens includes an optical part having an anterior optical surface and a posterior optical surface, and a haptic supporting the optical part, and at least one of the anterior optical surface and the posterior optical surface is a toric surface, and the method can include the following steps:

[0078] i) setting a set of initial values of the shape factor SF of the optical part, which comprises a plurality of numerical values; it is easily understood by those skilled in the art that the initial values of the shape factor SF can be roughly determined randomly according to design experience;

[0079] ii) calculating the optical power of the front optical surface of the intraocular lens according to each numerical value of the set of initial values of the shape factor SF and the target equivalent spherical power SE and the optical power of the back optical surface wherein,

[0080] iii) calculating the radius of curvature of the toric surface according to the calculated optical power of the front optical surface and the optical power of the back optical surface and the target cylindrical power CYL;

[0081] iv) calculating the value of the modulation transfer function according to the obtained toric surface, and judging whether the imaging quality of the intraocular lens is satisfied based on the calculated value of the modulation transfer function, that is, judging whether the imaging quality of each surface type is excellent or meets the design requirements through the calculated value of the modulation transfer function;

[0082] v) if the imaging quality is satisfied, selecting the numerical value of the shape factor corresponding to the design of the intraocular lens as the expected value of the shape factor; it is easily understood by those skilled in the art that, in order to pursue higher imaging quality, a set of initial values containing the expected value of the shape factor can be set again, and steps ii)-iv) can be repeated to select a shape factor with better imaging quality. The above operation can be repeated multiple times as needed until the shape factor with the best imaging quality is selected; if the imaging quality is not satisfied, steps i)-iv) are repeated, that is, the numerical value or range of the shape factor SF is re-set, and different toric intraocular lens surface types are designed, and the imaging quality is judged according to the modulation transfer function.

[0083] In step iii), if only one of the front optical surface and the back optical surface of the intraocular lens is designed as a toric surface, the toric surface can be represented as wherein R iy is the radius of curvature in a certain meridian direction of the toric surface, and R ix is the radius of curvature perpendicular to the meridian direction, wherein i = 1 or 2. Advantageously, in this case, a step of designing the other optical surface of the intraocular lens as an aspheric surface is also included, wherein the aspheric surface can be represented as: wherein y, z are the y-axis coordinate and z-axis coordinate of the aspheric surface in the rectangular coordinate system, c is the curvature, k is the conic coefficient, a2, a4, a6 are the aspheric coefficients.

[0084] In step iii), if both the anterior and posterior optical surfaces of the intraocular lens are designed as toric surfaces, the toric surface can be represented as: where i = 1 or 2, R iy is the radius of curvature in a certain meridional direction of the toric surface on the anterior or posterior optical surface, R ix is the radius of curvature perpendicular to the meridional direction, and wherein CYL1 is the cylinder of the anterior optical surface, CYL2 is the cylinder of the posterior optical surface, and SF2 is the second shape factor. Advantageously, in this case, the step of designing an aspherical surface on the anterior and / or posterior optical surface is also included, which can be characterized as: where the vertex of the surface is the coordinate origin O of the rectangular coordinate system, the optical axis is the z-axis, the sagittal plane is in the plane xOz, the meridional plane is in the plane yOz, and Cx and Cy represent the curvature of the vertex of the intraocular lens in the sagittal and meridional planes, respectively, Kx and Ky represent the quadratic surface coefficients of the intraocular lens in the sagittal and meridional planes, respectively, A i and B j are high-order aspherical coefficients, i and j are natural numbers greater than or equal to 0, x is the sagittal direction coordinate, and y is the meridional direction coordinate.

[0085] In another aspect of the present application, a toric intraocular lens designed by the design method according to the principles of the present application is also disclosed.

[0086] The present application takes the equivalent spherical power of 17D and the cylinder of 6D as the design index of the toric intraocular lens, designs according to the method disclosed in the present application, and verifies the imaging quality of the designed toric intraocular lens surface by modulation transfer function (MTF) in optical design software ZEMAX, and the results are as follows:

[0087] Example 1

[0088] Only the anterior optical surface of the intraocular lens is set as a toric surface, and the value of the shape factor SF is set to 0.7, 0.5, 0.2, 0.1, 0, -0.2, the surface corresponding to each SF value is designed, and the imaging quality of each surface is verified by modulation transfer function, and the MTF curves under different shape factors SF are as shown in Figure 2 The MTF values of the different designs of the anterior surface as a toric surface under 100 lp / mm resolution are shown in Table 1:

[0089] Table 1

[0090] SF low power meridian plane high power meridian plane 0.7 0.53 0.55 0.5 0.62 0.66 0.2 0.70 0.78 0.1 0.71 0.78 0 0.76 0.76 -0.2 0.36 0.49

[0091] As can be seen from Table 1, when the SF is between 0 and 0.7, preferably between 0 and 0.5, and more preferably between 0 and 0.2, the MTF values of the low-order meridional plane and the high-order meridional plane are close to 1, and the difference between the two MTF values is small, indicating that good imaging quality is achieved. Therefore, when the SF value is between 0 and 0.2, especially when the SF value is 0, it is optimal, so the surface shape corresponding to the SF value between 0 and 0.2 can be selected, and the MTF curve corresponding to the SF value between 0 and 0.2 is as shown in FIG. 2. Figure 3 As can be understood by those skilled in the art, a set of SF values of the shape factor can also be set again between 0 and 0.2, for example, 0, 0.05, 0.1, 0.15, 0.2, and the surface shape corresponding to each SF value is verified for imaging quality by the modulation transfer function to try to select a shape factor with better imaging quality.

[0092] Example 2

[0093] The front and rear optical surfaces of the intraocular lens are both set as toric surfaces, and the shape factor SF is set to 0, 0.1, and 0.2. The surface shape corresponding to each SF value is designed, and the imaging quality of each surface shape is verified by the modulation transfer function, and the MTF curves under different shape factors SF are as shown in FIG. 3. Figure 4 As can be seen from the MTF curve, the MTF values of different designs under the condition that the front and rear surfaces are both toric surfaces at a resolution of 100 lp / mm are as shown in Table 2:

[0094] Table 2

[0095] SF high power meridian plane low power meridian plane 0 0.51 0.59 0.1 0.61 0.7 0.2 0.54 0.78

[0096] As can be seen from Table 2, it is found that when the SF value is between 0 and 0.1, the MTF value is relatively good, but there is a large deviation in two directions. Therefore, a second shape factor SF2 is introduced, the surface shape corresponding to each SF / SF2 value is designed, and the MTF curve as shown in FIG. 4 is obtained. Figure 5 As can be seen from the MTF curve, the MTF values of different designs under the condition that the front and rear surfaces are both toric surfaces at a resolution of 100 lp / mm are as shown in Table 3, i.e., the MTF values of different designs under the condition that the front and rear surfaces have different SF values at a resolution of 100 lp / mm:

[0097] Table 3

[0098] SF / SF2 high power meridian plane low power meridian plane 0.2 / 0.6 0.72 0.77 0.1 / 0.6 0.78 0.80 0.2 / -0.6 0.26 0.26

[0099] As can be seen from Table 3, when the SF / SF2 value of the intraocular lens is between 0.1 / 0.6 and 0.2 / 0.6, the theoretical optimal level can be reached, the MTF value is close to 1 and the deviation in two directions is small, and the imaging quality is excellent. Those skilled in the art can easily understand that a set of SF / SF2 values between 0.1 / 0.6 and 0.2 / 0.6 can also be set again, for example, 0.1 / 0.6, 0.12 / 0.6, 0.14 / 0.6, 0.16 / 0.6, 0.18 / 0.6, 0.2 / 0.6, in order to try to select a more excellent imaging quality shape factor.

[0100] Example 3

[0101] The MTF curves of the intraocular lens with only single-sided toric surface and optimal SF value and the intraocular lens with double-sided toric surface and optimal SF value were compared, as shown in Figure 6 The MTF values of the two were compared, as shown in Table 4, i.e. the MTF values of the single-sided toric surface and the double-sided toric surface at 100 lp / mm resolution:

[0102] Table 4

[0103] toric design SF or SF / SF2 high power meridian plane low power meridian plane single surface toric 0 0.76 0.76 double surface toric 0.1 / 0.6 0.78 0.80

[0104] As Figure 6 and Table 4 can be seen, when the single-sided toric surface and the double-sided toric surface both have optimal SF or SF / SF2 values, the MTF value of the double-sided toric surface is closer to 1, and the imaging quality of the double-sided toric surface intraocular lens with optimal SF / SF2 value is better than that of the single-sided toric surface intraocular lens with optimal SF value.

[0105] The above verification results show that the design method of the toric intraocular lens according to the principle of the present application is simple in steps, and can effectively design a toric intraocular lens with excellent imaging quality, while solving the problems of cataract and astigmatism. In practical application, the toric intraocular lens with an equivalent spherical power of the optical part of 0D to 42D, a cylindrical power of 0.5D to 10D, and a spherical aberration of -0.3μm to 0.05μm can be designed by the method according to the principle of the present application, which greatly meets the needs of patients.

[0106] While at least one exemplary embodiment has been described above, it should be appreciated that many modifications can be made. It should also be appreciated that a exemplary embodiment and the many modifications of a exemplary embodiment described herein are only examples and are not intended to limit the scope, applicability or configuration of the application in any way. Rather, the preceding detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment or a exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the application as set forth in the appended claims and the legal equivalents thereof.

Claims

1. A toric intraocular lens comprising an optical part having an anterior optical surface and a posterior optical surface and a haptics supporting the optical part, characterized in that, At least one of the anterior and posterior optical surfaces is toric, the toric surface being designed according to the following steps: i) setting a set of initial values of a shape factor of the optical portion, including a plurality of numerical values; ii) calculating the optical power of the anterior optical surface and the optical power of the posterior optical surface as a function of the target equivalent spherical power of the intraocular lens and each value of the set of initial values, wherein, PAN is the optical power of the anterior optical surface and PPO is the optical power of the posterior optical surface, SE is the target equivalent spherical power, SF is the shape factor; iii) calculating the radius of curvature of the toric surface according to a target cylinder CYL of the intraocular lens, the optical power of the anterior optical surface and the optical power of the posterior optical surface; iv) calculating a value of a modulation transfer function of the intraocular lens according to the obtained toric surface, and judging whether the imaging quality of the intraocular lens is satisfied based on the calculated value of the modulation transfer function; v) if the imaging quality is satisfied, selecting the corresponding numerical value of the shape factor as an expected value of the shape factor to design the intraocular lens, or setting again a set of initial values including the expected value of the shape factor, repeating steps ii) - iv) to select a shape factor with better imaging quality; if the imaging quality is not satisfied, repeating steps i) - iv).

2. The toric intraocular lens of claim 1, wherein, One of the front and back optical surfaces is toric, wherein the toric surface is expressed as: where R iy is the radius of curvature in a certain meridional direction of the toric front and back optical surfaces, R ix is the radius of curvature perpendicular to the meridional direction, and i = 1 or 2.

3. The toric intraocular lens of claim 2, wherein, The method also includes the step of designing the other of the front and back optical surfaces as an aspheric surface, wherein the aspheric surface is characterized by: and wherein y, z are the y and z coordinates of the aspheric surface, c is the curvature, k is the conic constant, a2, a4, a6 are aspheric coefficients.

4. The toric intraocular lens of claim 1, wherein, The front and back optical surfaces are both toric surfaces, wherein the toric surface is expressed as: where i = 1 or 2, R iy is the radius of curvature in a meridional direction of the toric surface that is the front or back optical surface, R ix is the radius of curvature perpendicular to the meridional direction, and wherein, CYL1 is the cylinder of the front optical surface, CYL2 is the cylinder of the back optical surface, and SF2 is the second shape factor.

5. The toric intraocular lens of claim 4, wherein, Also included is the step of designing aspherical surfaces on the front and / or back optical surfaces, said aspherical surfaces being characterized by: wherein the vertex of the surface is the coordinate origin O, the optical axis is the z axis, the sagittal plane is in the plane xOz, the meridional plane is in the plane yOz, and Cx, Cy represent the curvature of the intraocular lens at the vertex in the sagittal and meridional planes, respectively, Kx and Ky represent the quadratic surface coefficients of the intraocular lens in the sagittal and meridional planes, respectively, A i and B j are high-order aspherical coefficients, i and j are natural numbers greater than or equal to 0, x is the sagittal direction coordinate, and y is the meridional direction coordinate.

6. The toric intraocular lens according to claim 2 or 3, characterized in that The value of the shape factor is between 0 and 0.

7.

7. The toric intraocular lens of claim 6, wherein, The value of the shape factor is between 0 and 0.

5.

8. The toric intraocular lens according to claim 4 or 5, characterized in that The value of the shape factor is between 0 and 0.

2.

9. The toric intraocular lens of claim 8, wherein, The value of the shape factor is between 0 and 0.

1.

10. The toric intraocular lens of claim 8, wherein, The value of the second shape factor is 0.

6.

11. The method of designing a toric intraocular lens according to claim 7 or 9, wherein, The equivalent spherical power of the intraocular lens is between 0D and 42D, and the cylinder is between 0.5D and 10D.

12. The toric intraocular lens of claim 11, wherein, The spherical aberration of the intraocular lens is between -0.3 μm and 0.05 μm.

13. A method of designing a toric intraocular lens comprising an optic portion having an anterior optical surface and a posterior optical surface and a haptics supporting the optic portion, characterized in that, At least one of the anterior and posterior optical surfaces is toric, the toric surface being designed according to the following steps: i) setting a set of initial values of a shape factor of the optical portion, including a plurality of numerical values; ii) calculating the optical power of the anterior optical surface and the optical power of the posterior optical surface as a function of the target equivalent spherical power of the intraocular lens and each value of the set of initial values, wherein, PAN is the optical power of the anterior optical surface and PPO is the optical power of the posterior optical surface, SE is the target equivalent spherical power, SF is the shape factor; iii) calculating the radius of curvature of the toric surface according to a target cylinder CYL of the intraocular lens, the optical power of the anterior optical surface and the optical power of the posterior optical surface; iv) calculating a value of a modulation transfer function of the intraocular lens according to the obtained toric surface, and judging whether the imaging quality of the intraocular lens is satisfied based on the calculated value of the modulation transfer function; v) if the imaging quality is satisfied, selecting the corresponding numerical value of the shape factor as an expected value of the shape factor to design the intraocular lens, or setting again a set of initial values including the expected value of the shape factor, repeating steps ii) - iv) to select a shape factor with better imaging quality; if the imaging quality is not satisfied, repeating steps i) - iv).

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