A multifocal intraocular lens based on coherent imaging

Abstract

The present invention discloses a multifocal intraocular lens based on coherent imaging, comprising an optical body, wherein the optical body is composed of two optical surfaces, the optical surfaces are spherical or aspherical, one of the optical surfaces is provided with a multifocal diffraction structure and a diffraction coherent imaging structure for providing multiple focal points by splitting and focusing; the multifocal diffraction structure and the diffraction coherent imaging structure constitute a diffraction coherent imaging structure; in the present invention, the diffraction coherent imaging structure improves the transition effect between focal points of the patient after the intraocular lens is implanted, increases the dynamic vision of the patient after the intraocular lens is implanted, enhances the continuity of the visual range between focal points of the multifocal intraocular lens, and improves the utilization rate of light energy by adjusting the period of the diffraction coherent imaging structure.

Description

Technical Field

[0001] The present invention relates to the technical field, and in particular to a multifocal intraocular lens based on coherent imaging. Background Art

[0002] Intraocular lenses (IOLs) are widely used in cataract surgery to replace the diseased natural intraocular lenses implanted in the patient's eyes. According to the number of focal points and imaging results, IOLs can be divided into monofocal IOLs, monofocal astigmatic IOLs, bifocal IOLs, trifocal IOLs, and extended depth of focus IOLs. Among them, bifocal IOLs are chosen by more and more patients because of their high cost-effectiveness.

[0003] Bifocal IOLs are mainly divided into small-addition bifocal IOLs that provide far and medium focus and large-addition bifocal IOLs that provide far and near focus. The mainstream bifocal IOLs on the market now are small-addition bifocal IOLs, which can provide patients with excellent far and medium vision and some near vision. The main reason why large-addition bifocal IOLs are gradually being eliminated by the market is that the distance between far and near focus is too far, there is no transition, and patients have poor visual adaptation after surgery. However, as cataract surgery patients are gradually getting younger, the demand for near vision is gradually increasing, and the demand for large-addition bifocal IOLs is also increasing. In the prior art, the focus formed by each diffraction peak in the multifocal intraocular lens is independent and the diffraction peak line width is relatively narrow, which will cause visual breakpoints in patients after implantation and functional visual impairment.

[0004] Therefore, optical design is needed to improve the transition between the focal points of multifocal intraocular lenses. Summary of the invention

[0005] Traditional multifocal diffractive intraocular lenses are a hybrid of refraction and diffraction optical designs, with a basic refractive structure for focusing and a multifocal diffraction structure for diffraction and spectroscopy. In view of the above-mentioned shortcomings of the prior art, the present invention provides a multifocal intraocular lens based on coherent imaging, a diffraction coherent imaging structure is designed based on coherent imaging, and a diffraction coherent imaging structure is formed after convolution with the diffraction structure in the spatial domain, so as to form multiple focal points and expand and enhance the transition between each focal point, increase the patient's visual quality and postoperative visual adaptation, and improve the utilization rate of light energy.

[0006] To achieve the above effects, the technical solution of the present invention is as follows:

[0007] The present invention provides a multifocal intraocular lens based on coherent imaging, comprising an optical body, wherein the optical body is composed of two optical surfaces, the optical surfaces are spherical or aspherical, and one of the optical surfaces has a multifocal diffraction structure and a diffraction coherent imaging structure for providing multiple focal points by splitting and focusing; the multifocal diffraction structure and the diffraction coherent imaging structure constitute a diffraction coherent imaging structure;

[0008] Method for determining the upper two optical surfaces of an optical body:

[0009] With the vertex of the optical surface as the origin O and the optical axis as the Z axis, an arbitrary spatial rectangular coordinate system is established, the horizontal axis X axis and the coordinate axis Y axis of the coordinate system are tangent to the optical surface, and the surface shape of the optical surface satisfies the equation on the above YZ plane:

[0010]

[0011] Wherein, Z(y) is the curve expression of the optical surface on the two-dimensional coordinate plane YZ, c is the reciprocal of the radius of curvature of the base spherical surface of the optical surface, y is the vertical distance from any point on the curve to the horizontal axis Z, A 2i is the optical surface high-order coefficient, m and n are both integers not less than 1 and n>m, K is the optical surface coefficient; when K and A 2i When it is 0, Z(y) is the equation of the sphere;

[0012] The design method of the multi-focal diffraction structure is:

[0013] The phase function φ that characterizes the multifocal diffraction structure is:

[0014]

[0015] Where r is the radial distance from a point on the optical axis, D is the diffraction period of the multi-focal diffraction structure, and λ is the main wavelength;

[0016] The design method of the diffraction coherence imaging structure is:

[0017] Perform Fourier transformation on the phase function φ of the multi-focal diffraction structure and convert it into the transfer function U(r) of the multi-focal diffraction structure in the spatial domain;

[0018] U(r)=A*exp[jkΦ] (3)

[0019] Where A is the phase transformation factor of the multi-focal diffraction structure; j is an imaginary number, and k is a spatial domain variable;

[0020] A diffraction coherent imaging structure with the same diffraction order as the multi-focal diffraction structure is constructed, and the phase function φ′ of the diffraction coherent imaging structure is expressed as:

[0021]

[0022] Where D′ is the diffraction period of the diffraction coherent imaging structure;

[0023] The phase function φ′ of the diffraction coherent imaging structure is Fourier transformed and converted into the transfer function U′(r) of the diffraction coherent imaging structure in the spatial domain:

[0024] U′(r)=A′*exp[jkΦ′]

[0025] Where A′ is the phase transformation factor of the diffraction coherent imaging structure;

[0026] The transfer function of the multifocal diffraction structure in the spatial domain and the transfer function of the diffraction coherent imaging structure in the spatial domain are convolved to obtain the transfer function G(r) of the intraocular lens:

[0027]

[0028] Where ξ is the convolution variable;

[0029] Perform inverse Fourier transform on G(r) to obtain the phase function φ(r) of the intraocular lens:

[0030] φ(r)=G(r)*e (-2πir) dr (6)

[0031] Setting m i The order is the diffraction order of the i-th artificial lens focus, according to m i Design the diffraction height H of the diffraction coherent imaging structure i :

[0032]

[0033] In the formula, h i is the distribution coefficient of the i-th order; n iol is the refractive index of the intraocular lens material, n w is the refractive index of the medium;

[0034] According to the phase function φ of the multi-focal diffraction structure and the diffraction height H of the diffraction coherent imaging structure i , and obtain the diffraction curve D of the diffraction coherent imaging structure 衍 :

[0035] D 衍 =φ(r)*H i (8)

[0036] The diffraction curve D of the diffraction coherence imaging structure 衍 Superimposed on any optical surface, the actual surface shape of the optical surface is obtained.

[0037] Furthermore, the optical body is a double convex / concave-convex lens sheet with an effective optical zone diameter of 5.0 to 6.5 mm and a center thickness of 0.2 to 1.25 mm.

[0038] Furthermore, the optical body has one or more additional focal points, and the additional optical power ranges from +1.5D to +5D.

[0039] Furthermore, the artificial lens also includes a first support haptic and a second support haptic, and the optical body (1) is located between the first support haptic and the second support haptic.

[0040] Furthermore, the optical body, the first support haptic and the second support haptic are an integrated structure, made of the same material and integrally formed.

[0041] Furthermore, the thickness of the first support haptic and the second support haptic are both 0.15-0.45 mm.

[0042] Furthermore, the surfaces of the first support loop and the second support loop are both provided with oblique sawtooth grooves or raised frosting.

[0043] Furthermore, the width of the oblique sawtooth groove or raised frosting is 0.2 to 1.0 mm.

[0044] Furthermore, the roughness of the frosting or the height of the oblique sawtooth is greater than 40 μm.

[0045] Furthermore, the angle α between the oblique edge of the oblique sawtooth and the plane to which the first support loop and the second support loop belong is between -20° and +20°.

[0046] It can be understood that the optical body has diffraction gratings of different heights, and the diffraction gratings of different heights constitute a multifocal diffraction structure; when light passes through the optical body, the multifocal diffraction structure can distribute the light at different diffraction focuses to form at least 2 effective focuses.

[0047] Furthermore, the multifocal intraocular lens processing steps of the present invention are as follows:

[0048] Design of base and rear surface:

[0049] First, determine the optical power and shape of the artificial lens, such as plano-convex, biconvex, plano-concave, biconcave, concave-convex, etc., build an initial model in Zemax, establish an evaluation function, and then optimize to obtain the best expected effect.

[0050] Design of multi-focal diffraction structure:

[0051] The number of additional focal points and the corresponding optical power are determined, and the phase function Φ(r) (such as formula 2) of the multifocal diffraction structure is determined according to the design and compressed to obtain the expected diffraction effect.

[0052] Design of diffraction coherence imaging structure:

[0053] According to the phase function of the multi-focal diffraction structure, its period is adjusted to form the phase function of the diffraction coherent imaging structure, and the diffraction coherent imaging structure is formed by convolution with the phase function of the multi-focal diffraction structure in the spatial domain, and the diffraction curve D of the diffraction coherent imaging structure corresponding to each radial distance r is calculated. 衍 , the diffraction curve D of the diffraction coherence imaging structure 衍 Superimposed on an optical surface in the optical zone, Z 合 =Z+D 衍， Get the actual surface shape Z of the optical surface 合 .

[0054] Turning the base refractive lens: Write a lathe program according to the processing parameters of the front and rear optical surfaces of the optical design; use diamond single-point cutting technology to turn the optical body; write a milling machine program to mill the shape of the optical area and the frosted / serrated loop.

[0055] Polished finish.

[0056] The intraocular lens can be first processed by a lathe to form an intraocular lens disc with a continuous visual range multifocal diffraction structure, then mechanically engraved to form the optical body of the intraocular lens, and the first support haptic and the second support haptic are mechanically cut to form.

[0057] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0058] The present invention is based on the principle of coherent imaging. On the basis of the traditional diffractive intraocular lens, a diffractive coherent imaging structure with the same phase function as the multifocal diffractive structure is designed to form a diffractive coherent imaging structure, and the diffractive coherent imaging structure is superimposed on the surface of the diffractive multifocal intraocular lens. The diffractive coherent imaging structure improves the transition effect between the focal points of the patient after the intraocular lens is implanted by adjusting the period of the diffractive coherent imaging structure, increases the dynamic vision of the patient after the intraocular lens is implanted, enhances the continuity of the visual range between the focal points of the multifocal intraocular lens, and improves the utilization rate of light energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a schematic diagram of the structure of the artificial lens of the present invention;

[0060] Figure 2 It is a USAF1951 resolution plate test chart under different optical powers within a continuous range in the eye model of the present invention;

[0061] Figure 3 It is a test chart of the USAF1951 resolution plate under different optical powers within a continuous range in the eye model of the present invention. DETAILED DESCRIPTION

[0062] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0063] Example 1

[0064] This embodiment provides a multifocal intraocular lens based on coherent imaging, including an optical body 1. Figure 1 The optical body 1 is composed of two optical surfaces, the optical surfaces are spherical or aspherical, one of the optical surfaces has a multi-focal diffraction structure and a diffraction coherent imaging structure for providing multiple focal points for splitting and focusing; the multi-focal diffraction structure and the diffraction coherent imaging structure constitute a diffraction coherent imaging structure;

[0065] Method for determining the upper two optical surfaces of the optical body 1:

[0066] With the vertex of the optical surface as the origin O and the optical axis as the Z axis, an arbitrary spatial rectangular coordinate system is established, the horizontal axis X axis and the coordinate axis Y axis of the coordinate system are tangent to the optical surface, and the surface shape of the aspheric surface satisfies the aspheric surface equation on the above YZ plane:

[0067]

[0068] In the formula, Z( y ) is the curve expression of the aspheric surface on the two-dimensional coordinate plane YZ, c is the reciprocal of the radius of curvature of the base spherical surface of the aspheric surface, y is the vertical distance from any point on the curve to the horizontal axis Z, A 2i is the aspheric high-order coefficient, m and n are both integers not less than 1 and n>m, K is the aspheric coefficient; when K and A 2i When it is 0, Z(y) is the equation of the sphere;

[0069] The design method of the multi-focal diffraction structure is:

[0070] The phase function φ of the multifocal diffraction structure is characterized by a polynomial:

[0071]

[0072] Wherein, r is the radial distance from a point on the optical axis plane (i.e., the pupil radius), D is the diffraction period of the multifocal diffraction structure, and λ is the main wavelength, in millimeters (mm).

[0073] The design method of the diffraction coherence imaging structure is:

[0074] Since the diffraction peak of the traditional diffraction intraocular lens is relatively narrow and changes dramatically between the maximum and minimum, each focus of the traditional diffraction intraocular lens is independent and sharp. Since there is a constant linear phase within the diffraction coherence bandwidth, there is stable imaging quality within this range. In order to increase the expansion and continuity of the focus, the present invention increases the coherence bandwidth of the intraocular lens by constructing a diffraction coherence imaging structure similar to the multi-focal diffraction structure.

[0075] Perform Fourier transformation on the phase function φ of the multi-focal diffraction structure and convert it into the transfer function U(r) of the multi-focal diffraction structure in the spatial domain;

[0076] U(r)=A*exp[jkΦ] (3)

[0077] Where A′ is the phase transformation factor (i.e., control parameter) of the multi-focal diffraction structure; j is an imaginary number, and k is a spatial domain variable;

[0078] A diffraction coherent imaging structure with the same diffraction order as the multi-focal diffraction structure is constructed. The phase function of the diffraction coherent imaging structure is the same as that of the multi-focal diffraction structure. The phase function φ′ of the diffraction coherent imaging structure is expressed as:

[0079]

[0080] Where D′ is the diffraction period of the diffraction coherent imaging structure;

[0081] The phase function φ′ of the diffraction coherent imaging structure is Fourier transformed and converted into the transfer function U′(r) of the diffraction coherent imaging structure in the spatial domain:

[0082] U′(r)=A′*exp[jkΦ′]

[0083] Where A′ is the phase transformation factor (i.e., control parameter) of the diffraction coherent imaging structure;

[0084] The transfer function of the multifocal diffraction structure in the spatial domain and the transfer function of the diffraction coherent imaging structure in the spatial domain are convolved to obtain the transfer function G(r) of the intraocular lens:

[0085]

[0086] Where ξ is the convolution variable;

[0087] Perform inverse Fourier transform on G(r) to obtain the phase function φ(r) of the intraocular lens:

[0088] φ(r)=G(r)*e (-2πir) dr (6)

[0089] Setting m iThe order is the diffraction order of the i-th artificial lens focus, according to m i Design the diffraction height H of the diffraction coherent imaging structure i :

[0090]

[0091] In the formula, h i is the distribution coefficient of the ith level (related to the energy distribution share between the focal points, a constant); n iol is the refractive index of the intraocular lens material, n w is the refractive index of the medium;

[0092] According to the phase function φ of the multi-focal diffraction structure and the diffraction height H of the diffraction coherent imaging structure i , and obtain the diffraction curve D of the diffraction coherent imaging structure 衍 :

[0093] D 衍 =φ(r)*H i (8)

[0094] The diffraction curve D of the diffraction coherence imaging structure 衍 Superimposed on any optical surface, the actual surface shape of the optical surface is obtained.

[0095] It can be seen that when the periods of the multifocal diffraction structure and the diffraction coherent imaging structure are equal, the coherent imaging presents periodic changes; when the periods of the multifocal diffraction structure and the diffraction coherent imaging structure are not equal, the coherent imaging is a continuous change, that is, there is no obvious maximum or minimum value, but it decays smoothly with the increase of distance. Therefore, adjusting the period of the intraocular lens diffraction coherent imaging structure can modulate the bandwidth of the coherent imaging, thereby increasing the transition between the focal points of the intraocular lens.

[0096] Example 2

[0097] This embodiment is implemented on the basis of Embodiment 1, and the artificial lens includes an optical body 1, a first support haptic 2 and a second support haptic 3. The optical body 1 is composed of two optical surfaces A and B. The diffraction coherent imaging structure composed of a multifocal diffraction structure and a diffraction coherent imaging structure is on the optical surface A.

[0098] The optical body 1, the first support haptic 2 and the second support haptic 3 are an integrated structure, made of the same material and integrally formed;

[0099] The diffraction coherence imaging structure is superimposed on an optical surface of the optical body 1 by lathing, and the diffraction coherence imaging structure is superimposed on the optical surface A;

[0100] The surfaces of the first supporting haptic 2 and the second supporting haptic 3 are both provided with oblique sawtooth grooves; the height of the oblique sawtooth is greater than 40 μm.

[0101] The diameter of the effective optical zone of the optical body 1 is 6.2 mm, and the central thickness is 0.58 mm. The thickness of the first support haptic 2 and the second support haptic 3 are both 0.35 mm.

[0102] The optical body 1 is made of hydrophobic polyacrylate with a refractive index of 1.544 and a dispersion coefficient of 45-55.

[0103] The surfaces of the first support haptic 2 and the second support haptic 3 are provided with a plurality of oblique sawtooth grooves, and the width of the oblique sawtooth grooves is 0.15 mm, and the angle α between the oblique edges of the oblique sawtooth and the plane to which the support haptic belongs is 20°.

[0104] The preparation method of the artificial lens is as follows:

[0105] Design plan: Design a bifocal intraocular lens with a focal power of 23D and an additional focal power of 3D.

[0106] Optical Design:

[0107] According to the focal power and additional focal power of the intraocular lens, an initial model was constructed in Zemax to optimize the parameters of the two optical surfaces (i.e., optical surfaces A and B) of the optical body 1, where the base radius was 18.63 mm and K = -3.26; and the phase function was constructed according to Formula 2, and the period D of the multifocal diffraction structure was selected to be 60 μm, and the period D' of the diffraction coherent imaging structure was selected to be 45 μm. According to Formula 3, the phase functions of the multifocal diffraction structure and the diffraction coherent imaging structure were Fourier transformed into transfer functions U(r) and U'(r) in the spatial domain, where the phase conversion factor A of the multifocal diffraction structure was 0.78, and the phase conversion factor A' of the diffraction coherent imaging structure was 0.65. Convolution was performed in the spatial domain according to Formula 5 to obtain the spatial domain transfer function G(r) of the coherent multifocal diffraction structure, and it was inversely Fourier transformed into the phase function φ.

[0108] Select the diffraction order as +1 and +2, the distribution constants are h+1=0.7, h+2=0.3, and the main wavelength is 0.546μμm.

[0109] The diffraction height is:

[0110]

[0111] The diffraction curve of the diffraction coherent imaging structure is obtained as D 衍 =φ(r)*H i .

[0112] The diffraction curve of the diffraction coherent imaging structure is superimposed on the substrate surface to obtain the actual surface shape of the optical surface and the processing curve Z 合 .

[0113] (3) Turning the base refractive lens: Write a lathe program according to the designed parameters of the optical zone; use diamond single-point cutting technology to turn the disc-shaped intraocular lens; write a milling machine program to mill the shape of the optical zone and the frosted haptic.

[0114] (4) Polishing to obtain an intraocular lens with a qualified optical surface.

[0115] (5) Analysis and testing in eye models

[0116] Results and discussion:

[0117] The IOL in Example 2 was introduced into the eye model required by ISO11979-2, and the USAF1951 resolution plate test chart with a 0.5D interval from 23D to 27D was obtained by optical equipment testing, as shown in FIG. Figure 2 As shown, a: 23D; b: 23.5D; c: 24D; d: 24.5D; e: 25D; f: 25.5D; g: 26D; h: 26.5D; i: 27D; It can be seen that the IOL has a focal depth range of about 1.5D at the focus 23D and 26D, which is much higher than the focal depth of about 1D at each focus of the normal dual focus.

[0118] Example 3

[0119] This embodiment is implemented on the basis of embodiment 1. Figure 1 As shown, a multifocal intraocular lens based on coherent imaging comprises an optical body 1, a first support haptic 2 and a second support haptic 3. The optical body 1 consists of two optical surfaces A and B. The diffraction coherent imaging structure composed of a multifocal diffraction structure and a diffraction coherent imaging structure is on the optical surface B.

[0120] The optical body 1, the first support haptic 2 and the second support haptic 3 are an integrated structure, made of the same material and integrally formed;

[0121] The diffraction coherence imaging structure is superimposed on an optical surface of the optical body 1 by lathing, and the diffraction coherence imaging structure is superimposed on the optical surface B;

[0122] The surfaces of the first supporting haptic 2 and the second supporting haptic 3 are both provided with oblique sawtooth grooves; the height of the oblique sawtooth is greater than 40 μm.

[0123] The diameter of the effective optical zone of the optical body 1 is 6.0 mm, and the central thickness is 0.61 mm. The thickness of the first support haptic 2 and the second support haptic 3 are both 0.42 mm.

[0124] The optical body 1 is made of hydrophobic polyacrylate with a refractive index of 1.544 and a dispersion coefficient of 45-55.

[0125] The surfaces of the first support loop 2 and the second support loop 3 are provided with a plurality of oblique sawtooth grooves, and the width of the oblique sawtooth grooves is 0.2 mm, and the angle α between the oblique edges of the oblique sawtooth and the plane to which the support loop belongs is 5°.

[0126] The preparation method of the artificial lens is as follows:

[0127] Design plan: Design a trifocal intraocular lens with an optical power of 18D and additional optical powers of 2D and 4D.

[0128] Optical Design:

[0129] According to the focal power and additional focal power of the intraocular lens, the initial model was constructed in Zemax, and the parameters of the two optical surfaces A and B of the optical body 1 were optimized, where the base radius was 18.29 mm and K = -3.21; and the phase function was constructed according to Formula 2, and the period D of the multifocal diffraction structure was selected to be 40 μm, and the period D' of the diffraction coherent imaging structure was selected to be 50 μm. According to Formula 3, the phase functions of the multifocal diffraction structure and the diffraction coherent imaging structure were Fourier transformed into transfer functions U(r) and U'(r) in the spatial domain, where the phase conversion factor A of the multifocal diffraction structure was 0.80, and the phase conversion factor A' of the diffraction coherent imaging structure was 0.71. Convolution was performed in the spatial domain according to Formula 5 to obtain the spatial domain transfer function G(r) of the coherent multifocal diffraction structure, and it was inversely Fourier transformed into the phase function φ.

[0130] The diffraction orders are selected as +1, +2 and +3, and the distribution constants are h +1 =0.5,h +2 =0.2,h +3 =0.3, the main wavelength is 0.555μm, and the diffraction height is:

[0131]

[0132] The diffraction curve of the diffraction coherent imaging structure is obtained as D 衍 =φ(r)*H i .

[0133] The diffraction curve of the diffraction coherent imaging structure is superimposed on the substrate surface to obtain the actual surface shape of the optical surface and the processing curve Z 合 .

[0134] (3) Turning the base refractive lens: Write a lathe program according to the designed parameters of the optical zone; use diamond single-point cutting technology to turn the disc-shaped intraocular lens; write a milling machine program to mill the shape of the optical zone and the frosted haptic.

[0135] (4) Polishing to obtain an intraocular lens with a qualified optical surface.

[0136] (5) Analytical testing in an eye model.

[0137] It should be noted that the IOL in Example 3 was introduced into the eye model required by ISO11979-2, and the USAF1951 resolution plate test chart with a 0.5D interval from 18D to 23D was obtained by optical equipment testing, as shown in FIG. Figure 3 As shown, a: 18D; b: 18.5D; c: 19D; d: 19.5D; e: 20D; f: 20.5D; g: 21D; h: 21.5D; i: 22D; j: 22.5; k: 23; It can be seen that the IOL has a focal depth range of about 1D at the focal points 18D, 19.5D and 21D, which is much higher than the focal depth of about 0.5D at each focus of the normal trifocals.

[0138] Implementing the embodiments of the present invention has the following beneficial effects:

[0139] The present invention utilizes the principle of coherent imaging, and by modulating the period of the multifocal diffraction structure and the diffraction coherent imaging structure, expands the bandwidth of coherent imaging, achieves the effect of smooth transition of imaging between the focal points of the artificial lens, and enhances the continuity of the visual range between the focal points of the artificial lens. The one-piece continuous visual range multifocal artificial lens is much simpler than the complex mechanical adjustable artificial lens structure, so that the artificial lens can be applied to complex ocular fluid environments, has good stability, and is not easy to induce secondary cataracts; the design of the frosted / serrated surface of the support loop increases the resistance to the movement of the loop, prevents the artificial lens from rotating in the capsular bag, and further increases the stability after surgery.

[0140] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A multifocal intraocular lens based on coherent imaging, comprising an optical body (1), characterized in that: The optical body (1) is composed of two optical surfaces, which are spherical or aspherical surfaces, and one of the optical surfaces has a multi-focal diffraction structure and a diffraction coherent imaging structure for providing multiple focal points for splitting and focusing; The multi-focal diffraction structure and the diffraction coherence imaging structure constitute a diffraction coherence imaging structure; Method for determining the upper two optical surfaces of the optical body (1): With the vertex of the optical surface as the origin O and the optical axis as the Z axis, an arbitrary spatial rectangular coordinate system is established, the horizontal axis X axis and the coordinate axis Y axis of the coordinate system are tangent to the optical surface, and the surface shape of the optical surface satisfies the equation on the above YZ plane: Wherein, Z(y) is the curve expression of the optical surface on the two-dimensional coordinate plane YZ, c is the reciprocal of the radius of curvature of the base spherical surface of the optical surface, y is the vertical distance from any point on the curve to the horizontal axis Z, A 2i is the optical surface high-order coefficient, m, n are both integers not less than 1 and n>m, K is the optical surface coefficient; when K and A 2i When it is 0, Z(y) is the equation of the sphere; The design method of the multi-focal diffraction structure is: The phase function φ that characterizes the multifocal diffraction structure is: Where r is the radial distance from a point on the optical axis, D is the diffraction period of the multi-focal diffraction structure, λ is the dominant wavelength; The design method of the diffraction coherence imaging structure is: The phase function φ of the multifocal diffraction structure is Fourier transformed and converted into the transfer function U(r) of the multifocal diffraction structure in the spatial domain: U(r)=A*exp[jkΦ] (3) Where A is the phase transformation factor of the multi-focal diffraction structure; j is an imaginary number, and k is a spatial domain variable; A diffraction coherent imaging structure with the same diffraction order as the multi-focal diffraction structure is constructed, and the phase function φ′ of the diffraction coherent imaging structure is expressed as: Where D′ is the diffraction period of the diffraction coherent imaging structure; The phase function φ′ of the diffraction coherent imaging structure is Fourier transformed and converted into the transfer function U′(r) of the diffraction coherent imaging structure in the spatial domain: U′(r)=A′*exp[jkφ′] Where A′ is the phase transformation factor of the diffraction coherent imaging structure; The transfer function of the multifocal diffraction structure in the spatial domain and the transfer function of the diffraction coherent imaging structure in the spatial domain are convolved to obtain the transfer function G(r) of the intraocular lens: Where ξ is the convolution variable; Perform inverse Fourier transform on G(r) to obtain the phase function φ(r) of the intraocular lens: φ(r)=G(r)*e (-2πir) dr (6) Setting m i The order is the diffraction order of the i-th artificial lens focus, according to m i Design the diffraction height H of the diffraction coherent imaging structure i : In the formula, h i is the distribution coefficient of the i-th order; n iol is the refractive index of the intraocular lens material, n w is the refractive index of the medium; According to the phase function φ of the multi-focal diffraction structure and the diffraction height H of the diffraction coherent imaging structure i , and obtain the diffraction curve D of the diffraction coherent imaging structure 衍 : D 衍 =φ(r)*H i (8) The diffraction curve D of the diffraction coherence imaging structure 衍 Superimposed on any optical surface, the actual surface shape of the optical surface is obtained.

2. The multifocal intraocular lens based on coherent imaging according to claim 1, characterized in that: The optical main body (1) is a double convex / concave-convex lens sheet with an effective optical zone diameter of 5.0 to 6.5 mm and a center thickness of 0.2 to 1.25 mm.

3. The multifocal intraocular lens based on coherent imaging according to claim 1, characterized in that: The optical body (1) has one or more additional focal points, and the additional focal power ranges from +1.5D to +5D.

4. The multifocal intraocular lens based on coherent imaging according to claim 1, characterized in that: The artificial lens further comprises a first support haptic (2) and a second support haptic (3), and the optical body (1) is located between the first support haptic (2) and the second support haptic (3).

5. The multifocal intraocular lens based on coherent imaging according to claim 4, characterized in that: The optical body (1), the first support haptic (2) and the second support haptic (3) are an integrated structure, made of the same material and integrally formed.

6. The multifocal intraocular lens based on coherent imaging according to claim 4, characterized in that: The thickness of the first support haptic (2) and the second support haptic (3) are both 0.15-0.45 mm.

7. The multifocal intraocular lens based on coherent imaging according to claim 4, characterized in that: The surfaces of the first support loop (2) and the second support loop (3) are both provided with oblique sawtooth grooves or raised frosted surfaces.

8. The multifocal intraocular lens based on coherent imaging according to claim 7, characterized in that: The width of the oblique sawtooth groove or the frosted protrusion is 0.2-1.0 mm.

9. The multifocal intraocular lens based on coherent imaging according to claim 7, characterized in that: The roughness of the frosting or the height of the oblique sawtooth is greater than 40 μm.

10. The multifocal intraocular lens based on coherent imaging according to claim 9, characterized in that: The angle α between the oblique edge of the oblique sawtooth and the plane to which the first support loop (2) and the second support loop (3) belong is between -20° and +20°.

Images