Orthokeratology lens design method, manufacturing method and orthokeratology lens

Abstract

The present invention provides a design method and a manufacturing method for orthokeratology lenses, wherein the shape parameters of the base curve area of ​​the orthokeratology lenses are determined according to the parameters of intraocular astigmatism, so that the cornea shaped by the base curve area has a specified astigmatism, and the specified astigmatism can be equal to the intraocular astigmatism in magnitude and opposite in direction, thereby compensating for or offsetting the intraocular astigmatism and improving the vision and clarity of the human eye.

Description

Technical Field

[0001] The present invention relates to a corneal reshaping lens and a design method and a manufacturing method thereof, and more specifically to a corneal reshaping lens with an astigmatism shaping structure in a base curve area and a design method and a manufacturing method thereof. Background Art

[0002] Rigid gas permeable corneal contact lenses for corneal reshaping (referred to as orthokeratology lenses) are a reversible, non-surgical refractive correction product. They are generally designed with an "inverse geometry" composed of several concentric arc areas, with base arc shaping areas, reverse arc areas, positioning areas and other areas. When worn at night, the orthokeratology lenses press on the cornea under the force of the eyelids, so that the wearer's cornea is shaped into a specified shape to correct refractive errors.

[0003] The base curve area of ​​orthokeratology lenses is generally designed as a sphere with a set radius of curvature, and is mainly used to correct myopia. Patent document 1 mentions a orthokeratology lens with more than one radius of curvature in the base curve area, which shapes the optical zone of the cornea into several areas with different radius of curvature, so that the human eye has multiple focal points at the same time, correcting refractive errors while combining correction of presbyopia. Patent document 2 mentions an orthokeratology lens with an aspherical base curve area, which is used to provide suitable peripheral defocus or aberration. These designs are all intended to shape the cornea into a 360-degree circularly symmetrical surface. Patent document 3 mentions an orthokeratology lens, whose inner surface is divided into a base curve area, a reversal curve area, a positioning curve area and a peripheral curve area from the center to the periphery, and the positioning curve area is a multi-zone toroidal surface. Here, the positioning curve area on the inner surface of the orthokeratology lens is designed as a multi-zone toroidal surface, which is intended to improve the degree of fit between it and the cornea and achieve the effect of lens positioning and centering.

[0004] Astigmatism is a common low-order aberration of the human eye that has a direct impact on vision. Astigmatism exceeding 0.75D can cause a sharp drop in the resolution of the human eye. The astigmatism of the human eye is caused by the different radii of curvature (refractive power) on different meridians. After passing through the human eye, light rays of different meridians cannot be focused (form a focus) at the same time in the eye, but form two mutually perpendicular focal lines in space, which will cause deformation of the image and blurred vision. As the human eye is an optical system, the cornea and the lens are the two major refractive elements. Astigmatism of the human eye may be caused by any one of the refractive elements, or several refractive elements may have astigmatism. Astigmatism has an axial direction, which generally refers to the angle between the direction of maximum / minimum refractive power and the horizontal direction of the human eye. The astigmatism of the cornea and the lens may be in the same direction or in different directions.

[0005] After wearing orthokeratology lenses on a cornea with astigmatism, the central optical zone is shaped into a convoluted symmetrical surface. If the wearer's cornea has astigmatism, the corneal astigmatism can be corrected by wearing orthokeratology lenses. However, if the wearer has intraocular astigmatism, the intraocular astigmatism cannot be corrected after wearing orthokeratology lenses, and the visual quality is still affected. If the direction of corneal astigmatism is opposite and complementary to the direction of intraocular astigmatism, the astigmatism of the whole eye will increase after wearing orthokeratology lenses, making the wearer's visual quality worse. Current orthokeratology lenses cannot solve the problem of intraocular astigmatism.

[0006] Background technology literature:

[0007] Patent document 1: CN108008544A

[0008] Patent document 2: CN106291977A

[0009] Patent document 3: CN202453593U Summary of the invention

[0010] The purpose of the present invention is to provide a corneal reshaping lens with astigmatism correction function in the base curve area and a manufacturing method thereof. The corneal reshaping lens can shape the corneal optical zone into a specified astigmatism shape, compensate for intraocular astigmatism, and reduce / correct the astigmatism of the entire eye.

[0011] To achieve the above-mentioned purpose, the present invention provides a method for designing a corneal reshaping lens, wherein the corneal reshaping lens has an inner surface facing the human cornea when worn, and the inner surface includes a base curve area located in the center, comprising the following steps: an intraocular astigmatism obtaining step, obtaining parameters of the intraocular astigmatism; and a base curve area parameter determination step, determining shape parameters of the base curve area according to the parameters of the intraocular astigmatism, so that the cornea shaped by the base curve area has a specified astigmatism, and the specified astigmatism can compensate for the intraocular astigmatism.

[0012] The present invention is different from the existing technical concepts. It does not try to eliminate the astigmatism of the cornea that is the shaping object, but deliberately makes the cornea have a certain astigmatism (i.e., prescribed astigmatism) after shaping. By actively forming and controlling this astigmatism, the influence of intraocular astigmatism can be compensated or even eliminated, thereby making the astigmatism of the whole eye controllable, and reducing or correcting the astigmatism of the whole eye after shaping.

[0013] Preferably, in the present invention, the base arc region has a toroidal surface shape.

[0014] Preferably, in the present invention, the base arc region extends in a sine curve shape or a cosine curve shape in the circumferential direction.

[0015] Preferably, in the intraocular astigmatism acquisition step, the parameters of the intraocular astigmatism are determined based on the parameters of the anterior corneal surface astigmatism and the parameters of the whole eye astigmatism.

[0016] In the present invention, preferably, the parameter of the anterior corneal surface astigmatism is a parameter within 6 mm, within 5 mm, or within 3 mm of the corneal diameter.

[0017] In addition, to achieve the above-mentioned purpose, the present invention also provides a method for designing orthokeratology lenses, wherein the orthokeratology lenses have an inner surface facing the human cornea when worn, wherein the inner surface includes a base curve area located in the center and an adaptation curve area located on the outer peripheral side of the base curve area, wherein the base curve area and the adaptation curve area have a toric surface shape, and the design method includes the following steps: obtaining the size and direction of the anterior corneal astigmatism and the whole eye astigmatism; determining the size and direction of the intraocular astigmatism according to the size and direction of the anterior corneal astigmatism and the whole eye astigmatism; and determining the size and direction of the intraocular astigmatism according to the size and direction of the intraocular astigmatism. The size of the toroidal surface of the base curve zone is determined, and the direction parameter of the toroidal surface of the base curve zone is determined according to the direction of the intraocular astigmatism, so that the cornea shaped by the base curve zone has a specified astigmatism, and the specified astigmatism can compensate for the intraocular astigmatism; the shape of the corneal area where the adaptation curve zone is located, that is, the area where the corneal adaptation curve zone is located is obtained; the curvature radius parameter and the direction parameter of the adaptation curve zone are determined according to the shape of the area where the corneal adaptation curve zone is located; and the angle between the direction parameter of the base curve zone and the direction parameter of the adaptation curve zone is determined.

[0018] Preferably, the prescribed astigmatism and the intraocular astigmatism are substantially the same in magnitude and opposite in direction.

[0019] Preferably, the curvature radius parameter includes a curvature radius in a flat K direction and a curvature radius in a steep K direction.

[0020] Preferably, the present invention uses the flat K direction or the steep K direction as the direction parameter.

[0021] In addition, to achieve the above-mentioned purpose, the present invention also provides a method for manufacturing a corneal reshaping lens, wherein the corneal reshaping lens has an inner surface facing the human cornea when worn, and the inner surface includes a base curve area located in the center, comprising the following steps: an intraocular astigmatism obtaining step, obtaining parameters of the intraocular astigmatism; and a base curve area parameter determination step, determining shape parameters of the base curve area according to the parameters of the intraocular astigmatism, so that the cornea shaped by the base curve area has a specified astigmatism, and the specified astigmatism can compensate for the intraocular astigmatism.

[0022] Preferably, the base curve area has a toric surface shape; the base curve area extends in a sine curve shape or a cosine curve shape in the circumferential direction; in the intraocular astigmatism acquisition step, the parameters of the intraocular astigmatism are determined according to the parameters of the anterior corneal surface astigmatism and the parameters of the whole eye astigmatism; the parameters of the anterior corneal surface astigmatism are parameters within 6 mm, within 5 mm or within 3 mm of the corneal diameter.

[0023] In addition, to achieve the above-mentioned purpose, the present invention also relates to a method for manufacturing orthokeratology lenses, wherein the orthokeratology lenses have an inner surface facing the human cornea when worn, wherein the inner surface includes a base curve area located in the center and an adaptation curve area located on the outer peripheral side of the base curve area, wherein the base curve area and the adaptation curve area have a toric surface shape, and the manufacturing method includes the following steps: obtaining the size and direction of the anterior corneal astigmatism and the whole eye astigmatism; determining the size and direction of the intraocular astigmatism according to the size and direction of the anterior corneal astigmatism and the whole eye astigmatism; and determining the size and direction of the intraocular astigmatism according to the size and direction of the intraocular astigmatism. The size of the toroidal surface of the base curve zone is determined, and the direction parameter of the toroidal surface of the base curve zone is determined according to the direction of the intraocular astigmatism, so that the cornea shaped by the base curve zone has a specified astigmatism, and the specified astigmatism can compensate for the intraocular astigmatism; the shape of the corneal area where the adaptation curve zone is located, that is, the area where the corneal adaptation curve zone is located is obtained; the curvature radius parameter and the direction parameter of the adaptation curve zone are determined according to the shape of the area where the corneal adaptation curve zone is located; and the angle between the direction parameter of the base curve zone and the direction parameter of the adaptation curve zone is determined.

[0024] In the manufacturing method, preferably, the prescribed astigmatism is substantially the same size as the intraocular astigmatism and has an opposite direction; the curvature radius parameter includes a curvature radius in a flat K direction and a curvature radius in a steep K direction, and the flat K direction or the steep K direction is used as the direction parameter.

[0025] In addition, to achieve the above-mentioned purpose, the present invention also relates to a corneal reshaping lens, which has an inner surface facing the human cornea when worn, and the inner surface includes a base curve area located in the center, and the base curve area has a toric surface shape. The base curve area is constructed so that the cornea shaped by the base curve area has a specified astigmatism, and the specified astigmatism can compensate for the intraocular astigmatism.

[0026] Preferably, in the present invention, the base arc region extends in a sine curve shape or a cosine curve shape in the circumferential direction.

[0027] Preferably, in the present invention, the inner surface further comprises an adapting arc zone located on the outer peripheral side of the base arc zone, and the adapting arc zone has a toroidal surface shape.

[0028] Preferably, in the present invention, an angle α is formed between the toroidal shape of the base arc region and the toroidal shape of the matching arc region, and 0°≤α≤180°.

[0029] Preferably, for the base curve area, the direction with the largest radius of curvature is called the flat K direction, and the radius of curvature is recorded as R1, and the direction with the smallest radius of curvature is called the steep K direction, and the radius of curvature is recorded as R2, wherein the directions R1 and R2 are perpendicular to each other, and a three-dimensional coordinate system is established with the center of the base curve of the orthokeratology lens as the vertex, wherein the optical axis direction of the orthokeratology lens is the Z axis, and the plane perpendicular to the optical axis and passing through the center of the base curve is the base plane, and z is the height of any point on the base curve surface from the base plane, and the surface shape of the base curve area satisfies the formula:

[0030]

[0031] C1 and C2 are the curvatures of the base arc area in the flat K direction and the steep K direction, that is: C1 = 1 / R1, C2 = 1 / R2, (r, θ) is the polar coordinate of any point on the base arc surface projected onto the base plane, and the polar coordinate takes the center of the base arc as the center of the circle and the steep K direction as the polar axis.

[0032] Preferably, in the present invention, the curvature radius R1 of the base arc zone in the flat K direction is 6.00-10.50 mm, 7.00-10.00 mm or 7.50-9.50 mm, and the curvature radius R2 in the steep K direction is 5.42-10.26 mm, 6.23-9.78 mm or 6.62-9.30 mm.

[0033] Preferably, in the present invention, the diameter of the base arc region in the flat K direction is 4.5-8.0 mm, 5.0-7.0 mm or 5.2-6.5 mm.

[0034] Preferably, in the present invention, the height difference between the flat K-direction surface height and the steep K-direction surface height of the base arc region at a diameter of 3.0 mm is 10.7 to 101.8 μm, 10.7 to 75.8 μm or 10.7 to 50.2 μm.

[0035] Preferably, the curvature radius of the adaptation arc zone in the flat K direction is 6.00-9.50 mm, 6.50-9.00 mm or 7.00-8.50 mm, and the curvature radius in the steep K direction is 5.42-9.43 mm, 5.83-8.94 mm or 6.23-8.45 mm.

[0036] The present invention proposes a corneal reshaping lens with a complex surface design in the base curve area and a design and manufacturing method thereof. By adopting the present invention, the cornea can have a specified astigmatism after shaping, and the specified astigmatism can be equal to the intraocular astigmatism in magnitude and opposite in direction, thereby compensating or offsetting the intraocular astigmatism and improving the vision and clarity of the human eye. In order to achieve the directional stability of astigmatism, the corneal reshaping lens has a complex surface design in the adaptation curve area, and the relative position stability between the corneal reshaping lens and the cornea is achieved through adaptive matching between tears and corneal topography. The angle between the base curve area and the adaptation curve area is stable, so the direction of corneal astigmatism shaping by the base curve area every night is limited to be stable, which can ensure the stability of astigmatism correction.

[0037] <Definition of terms>

[0038] Unless otherwise specified, the following definitions apply to the terms used in this specification.

[0039] A toric surface is an optical surface with different radii of curvature in different meridian directions, also called a Toric surface or a complex surface.

[0040] The base curve area (BC) is located in the center of the orthokeratology lens and is the inner surface of the optical zone. It is used to compress the anterior surface of the cornea and shape it into its shape. This area of ​​the cornea after shaping is the optical zone, which plays a role in optical imaging.

[0041] The reversal arc zone (RC) is the second area closely connected to the base arc zone. It connects the base arc zone and the fitting arc zone, forming a gap between the orthokeratology lens and the anterior surface of the cornea, storing tears and promoting tear circulation.

[0042] The adaptation arc zone (AC) is also called the positioning arc zone, matching arc zone, etc. It is adjacent to the inversion arc zone. This area matches the shape of the cornea and plays a positioning role.

[0043] The peripheral arc zone (PC) is optional and is located at the outermost edge of the orthokeratology lens. It is closely connected to the fitting arc zone and is generally flatter than the fitting arc zone. It presents a certain tilt angle with the corneal surface to ensure the exchange and circulation of tears and oxygen between the cornea and the periphery of the orthokeratology lens.

[0044] In addition, unless otherwise defined, the meaning of all technical terms used herein is consistent with that commonly understood by those skilled in the art to which the present invention belongs. If there is any inconsistency, the present specification and its included definitions shall prevail. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is the view along the optical axis of the orthokeratology lens;

[0046] Figure 2 It is the view of the base arc area seen along the optical axis;

[0047] Figure 3 It is an oblique view of the base arc area;

[0048] Figure 4 It is a diagram of the variation of the sagittal height in the circumferential direction of the base arc area. DETAILED DESCRIPTION

[0049] Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0050] <Overview of the structure of orthokeratology lenses>

[0051] Figure 1 It is the view along the optical axis of the orthokeratology lens; Figure 2 It is the view of the base arc area seen along the optical axis; Figure 3 It is an oblique view of the base arc area; Figure 4 It is a diagram of the variation of the sagittal height in the circumferential direction of the base arc area.

[0052] like Figure 1 As shown, the orthokeratology lens 10 is distributed from the center to the outside with a base curve area 1, an inversion curve area 2, an adaptation curve area 3, and a side curve area 4, wherein the base curve area 1 has a toric surface design, with different curvature radii in different meridian directions, and the front view shape tends to be elliptical, which is used to shape the cornea into a corresponding toric surface shape, correct myopia and provide astigmatism; the adaptation curve area 3 has a toric surface design, and the front view shape tends to be elliptical, which is consistent with the shape of the cornea in this area, and plays a positioning role; the inversion curve area 2 is a natural connection between the base curve area and the adaptation curve area, and the edge shape near the base curve area is consistent with the base curve area, and the edge shape near the adaptation curve area is consistent with the adaptation curve area; the side curve area 4 is a normal circular design, which is slightly tilted than the corneal shape, and plays a role in tear circulation. In some embodiments, the adaptation curve area 3 and the side curve area 4 are the same arc, and no distinction is made.

[0053] The base arc region 1 has different curvature radii on different meridians. In the 360° direction, the direction with the largest curvature radius is called the flat K direction (denoted as y1, which coincides with the major axis direction of the ellipse when observed along the optical axis, see Figure 3 ), the radius of curvature is denoted as R1, and the direction with the smallest radius of curvature is called the steep K direction (denoted as x1, which coincides with the direction of the minor axis of the ellipse when observed along the optical axis, see Figure 3 ), the radius of curvature is recorded as R2, where R1 is perpendicular to R2.

[0054] A three-dimensional coordinate system is established with the center of the base curve area 1 of the orthokeratology lens as the vertex, wherein the optical axis direction of the orthokeratology lens is the Z axis, which is perpendicular to the optical axis, and the surface passing through the center of the base curve area is the base plane, and z is the height of any point on the surface of the base curve area from the base plane. The surface shape of the base curve area 1 satisfies the formula:

[0055]

[0056] Among them, C1 and C2 are the curvatures of the base arc area in the flat K direction and steep K direction, that is, C1 = 1 / R1, C2 = 1 / R2. (r,θ) is the polar coordinates of any point on the surface of the base arc area projected onto the base plane (see Figure 2 ), the polar coordinate takes the center of the base arc area as the center of the circle and the steep K direction as the polar axis.

[0057] See also Figure 4 , the base arc area 1 is in the 360-degree circumferential direction, and the height z satisfies the sine / cosine distribution state.

[0058] The curvature radius R1 of the base arc region 1 in the flat K direction is between 6.00 and 10.50 mm, preferably, 7.00 to 10.00 mm, more preferably, 7.50 to 9.50 mm. R2 is between 5.42 and 10.26 mm, preferably, 6.23 to 9.78 mm, more preferably, 6.62 to 9.30 mm.

[0059] The diameter of the base arc region in the flat K direction is between 4.5 and 8.0 mm, preferably, between 5.0 and 7.0 mm, and more preferably, between 5.2 and 6.5 mm.

[0060] The height difference between the flat K-direction surface height and the steep K-direction surface height of the base arc area at a diameter of 3.0 mm is between 10.7 and 101.8 μm, preferably, between 10.7 and 75.8 μm, and more preferably, between 10.7 and 50.2 μm.

[0061] With the shaping of the base curve area, the cornea can obtain an astigmatism between 0.75 and 6.00D to correct the intraocular astigmatism.

[0062] The toroidal surface of the adapting arc zone is similar to the base arc zone in characteristics, and is also a toroidal surface with a height presenting a sine / cosine distribution. The curvature radius of the adapting arc zone in the flat K direction is between 6.00 and 9.50 mm, preferably, 6.50 to 9.00 mm, and more preferably, 7.00 to 8.50 mm. The curvature radius in the steep K direction is between 5.42 and 9.43 mm, preferably, 5.83 to 8.94 mm, and more preferably, 6.23 to 8.45 mm.

[0063] There is an angle α between the flat K direction of the matching arc zone and the flat K direction of the base arc zone, and 0°≤α≤180°.

[0064] <Design and manufacturing method of orthokeratology lenses>

[0065] The design and manufacturing method of orthokeratology lenses of this embodiment comprises the following steps:

[0066] (1) Measure the size and direction of the anterior corneal astigmatism and the whole eye astigmatism, and calculate the size T and direction of the intraocular astigmatism For example, the direction with the smallest refractive power in the eye is defined as Taking this as the design target of the curvature radius of the flat K and steep K of the base curve area of ​​the orthokeratology lens, the shape of the base curve area of ​​the orthokeratology lens is determined, wherein the curvature radii R1 and R2 in the flat K and steep K directions (equivalent to the "curvature radius parameters of the base curve area" in the present invention) satisfy:

[0067]

[0068] Among them, the unit of R1 and R2 is mm, and the unit of T is "D".

[0069] The measurement range is within 6 mm of corneal diameter, preferably within 5 mm, and more preferably within 3 mm. The measurement method can be a combination of corneal topography and an objective ophthalmometer, or a combination of corneal topography and a whole-eye aberration measurement device such as iTrace, as well as other methods for determining the size and direction of intraocular astigmatism and anterior corneal astigmatism.

[0070] The astigmatism of the anterior surface of the cornea can be obtained through corneal topography. The size and direction of the astigmatism of the whole eye can be obtained through other methods or equipment such as objective ophthalmometers. The size and direction of the astigmatism in the eye can be calculated using vector calculation methods:

[0071] Astigmatism on the anterior corneal surface is marked by Among them, T2 represents the size of the astigmatism on the anterior surface of the cornea. Represents the axis of astigmatism on the anterior corneal surface; the astigmatism of the entire eye is marked as T3 represents the size of the astigmatism of the whole eye. represents the axis of astigmatism for the entire eye; intraocular astigmatism is marked as T1 represents the size of the astigmatism in the eye. Represents the axis of intraocular astigmatism. It is whole eye astigmatism Astigmatism related to the anterior corneal surface The vector difference is:

[0072]

[0073] in,

[0074]

[0075]

[0076] The value of intraocular astigmatism is determined, and then the shape of the base curve area of ​​the orthokeratology lens is determined. The astigmatism provided by the complex surface of the base curve area is similar in size to the intraocular astigmatism (or substantially the same in size) and opposite in direction, which plays a role in compensating (offsetting) the intraocular astigmatism.

[0077] Here is an example of determining astigmatism in an eye:

[0078] a Before wearing, the astigmatism of the whole eye is -5.50DS-3.00DC×180, that is, the myopia degree is -5.50D, the astigmatism degree is -3.00D, and the astigmatism direction is 180°.

[0079] b The measurement results of the anterior surface of the cornea before wearing are: 43.25D@180, 46.75D@90, that is, the flat K value is 43.25D in the direction of 180°, and the steep K value is 46.75D in the direction of 90°.

[0080] c The astigmatism of the anterior corneal surface is: 43.25-46.75=-3.50D, direction 180°.

[0081] dIntraocular astigmatism is: whole eye astigmatism - corneal astigmatism = (-3.00×180) - (-3.50×180) = 0.50×180.

[0082] (2) For example, based on the corneal topography, the shape of the area where the corneal adaptation arc zone is located (the corneal area where the adaptation arc zone is located) is measured to determine the curvature radii in the flat K and steep K directions of the adaptation arc zone, thereby determining the surface shape of the orthokeratology lens adaptation arc zone. The direction of the flat K of the adaptation arc zone is recorded as (The direction of the flat K of the fitting arc area is the direction of the flat K of the cornea, which is also the direction of corneal astigmatism. Equivalent to the "directional parameters of the annular surface of the adapted arc zone" in the present invention).

[0083] (3) According to the size and direction of intraocular astigmatism and the size and direction of corneal astigmatism Matching arc area flat K direction Determine the flat K direction of the base curve area of ​​orthokeratology lenses K direction parallel to the matching arc area The angle α is:

[0084]

[0085] Base arc area flat K direction It is the direction of intraocular astigmatism, the base curve area is flat K direction It is equivalent to the "directional parameter of the toroidal surface of the base arc region" in the present invention.

[0086] After determining the various parameters, orthokeratology lenses are produced.

[0087] <Example of design method for curvature radii R1 and R2 in the flat K and steep K directions of the base arc area>

[0088] The refractive state of the cornea is mainly determined by its curvature radius. In practical applications, the commonly used conversion relationship between the curvature radius of the cornea and the corneal refractive power is:

[0089]

[0090] Where K is the diopter of the cornea, in D, R1 is the radius of curvature of the anterior surface of the cornea in the K direction, in mm, and n is the refractive index of the cornea. For example, n can be 1.3375. When n is 1.3375, the above formula is

[0091]

[0092] R1 is determined by the above formula, and R2 is determined by R1 and intraocular astigmatism T. The relationship between the three is as follows:

[0093]

[0094] Right now

[0095]

[0096] Example

[0097]

[0098] Beneficial Effects

[0099] By adopting this embodiment, the base curve area shapes the cornea into a toric surface. After shaping, an astigmatism surface will be formed on the front surface of the cornea, which has a post-shaping optical effect and can provide a specified astigmatism. This astigmatism is equal to the intraocular astigmatism in magnitude and opposite in direction, thus offsetting the intraocular astigmatism and improving the vision and clarity of the human eye.

[0100] The adapting arc zone achieves the relative position stability between the orthokeratology lens and the cornea through adaptive matching between tears and corneal topography, while the astigmatism angle between the base arc zone and the adapting arc zone is stable. Therefore, the astigmatism shaping direction of the cornea by the base arc zone is limited to be stable every night, thus ensuring the stability of astigmatism correction.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for designing a corneal reshaping lens, wherein the corneal reshaping lens has an inner surface facing the cornea of ​​a human eye when worn, the inner surface including a base curve area located in the center, It is characterized in that The following steps are involved: an intraocular astigmatism obtaining step, obtaining parameters of the intraocular astigmatism, wherein the intraocular astigmatism is a vector difference between the whole eye astigmatism and the anterior corneal surface astigmatism; and The base curve area parameter determination step determines the shape parameters of the base curve area according to the parameters of the intraocular astigmatism, so that the cornea shaped by the base curve area has a specified astigmatism, and the specified astigmatism can compensate for the intraocular astigmatism.

2. The orthokeratology lens design method according to claim 1, characterized in that: The base arc region has a toroidal surface shape.

3. The orthokeratology lens design method according to claim 2, characterized in that: The base arc region extends in a sine curve shape or a cosine curve shape in the circumferential direction.

4. The orthokeratology lens design method according to claim 1, characterized in that: In the intraocular astigmatism acquisition step, the parameters of the intraocular astigmatism are determined according to the parameters of the anterior corneal surface astigmatism and the parameters of the whole eye astigmatism.

5. The orthokeratology lens design method according to claim 4, characterized in that: The parameters of the anterior corneal astigmatism are parameters within 6 mm, within 5 mm, or within 3 mm of the corneal diameter.

6. A method for designing a corneal reshaping lens, wherein the corneal reshaping lens has an inner surface facing the cornea of ​​a human eye when worn, the inner surface includes a base curve area located in the center and an adaptation curve area located on the outer side of the base curve area, the base curve area and the adaptation curve area have a toric surface shape, characterized in that: The steps include: Obtain the size and direction of the anterior corneal surface astigmatism and the whole eye astigmatism; Determining the magnitude and direction of intraocular astigmatism according to the magnitude and direction of the anterior corneal surface astigmatism and the whole eye astigmatism, wherein the intraocular astigmatism is the vector difference between the whole eye astigmatism and the anterior corneal surface astigmatism; Determine the curvature radius parameter of the toroidal surface of the base curve area according to the magnitude of the intraocular astigmatism, and determine the direction parameter of the toroidal surface of the base curve area according to the direction of the intraocular astigmatism, so that the cornea shaped by the base curve area has a prescribed astigmatism, and the prescribed astigmatism can compensate for the intraocular astigmatism; Obtaining the shape of the corneal region where the adaptation arc zone is located, that is, the region where the corneal adaptation arc zone is located; Determine the curvature radius parameter and direction parameter of the corneal adaptation arc zone according to the shape of the area where the corneal adaptation arc zone is located; The angle between the direction parameter of the base arc area and the direction parameter of the adaptation arc area is determined.

7. The orthokeratology lens design method according to claim 6, characterized in that: The prescribed astigmatism is substantially the same in magnitude as the intraocular astigmatism, but opposite in direction.

8. The method for designing orthokeratology lenses according to claim 6, characterized in that: The curvature radius parameter includes a curvature radius in a flat K direction and a curvature radius in a steep K direction, and the flat K direction or the steep K direction is used as the direction parameter.

9. A method for manufacturing a corneal reshaping lens, wherein the corneal reshaping lens has an inner surface facing the cornea of ​​a human eye when worn, the inner surface including a base curve area located in the center, It is characterized in that The following steps are involved: an intraocular astigmatism obtaining step, obtaining parameters of the intraocular astigmatism, wherein the intraocular astigmatism is a vector difference between the whole eye astigmatism and the anterior corneal surface astigmatism; and The base curve area parameter determination step determines the shape parameters of the base curve area according to the parameters of the intraocular astigmatism, so that the cornea shaped by the base curve area has a specified astigmatism, and the specified astigmatism can compensate for the intraocular astigmatism.

10. The method for manufacturing orthokeratology lenses according to claim 9, characterized in that: The base arc region has a toroidal surface shape.

11. The method for manufacturing orthokeratology lenses according to claim 10, characterized in that: The base arc region extends in a sine curve shape or a cosine curve shape in the circumferential direction.

12. The method for manufacturing orthokeratology lenses according to claim 9, characterized in that: In the intraocular astigmatism acquisition step, the parameters of the intraocular astigmatism are determined according to the parameters of the anterior corneal surface astigmatism and the parameters of the whole eye astigmatism.

13. The method for manufacturing orthokeratology lenses according to claim 12, characterized in that: The parameters of the anterior corneal astigmatism are parameters within 6 mm, within 5 mm, or within 3 mm of the corneal diameter.

14. A method for manufacturing a corneal reshaping lens, wherein the corneal reshaping lens has an inner surface facing the cornea of ​​a human eye when worn, the inner surface includes a base curve area located in the center and an adaptation curve area located on the outer side of the base curve area, the base curve area and the adaptation curve area have a toric surface shape, characterized in that: The steps include: Obtain the size and direction of the anterior corneal surface astigmatism and the whole eye astigmatism; Determining the magnitude and direction of intraocular astigmatism according to the magnitude and direction of the anterior corneal surface astigmatism and the whole eye astigmatism, wherein the intraocular astigmatism is the vector difference between the whole eye astigmatism and the anterior corneal surface astigmatism; Determine the curvature radius parameter of the toroidal surface of the base curve area according to the magnitude of the intraocular astigmatism, and determine the direction parameter of the toroidal surface of the base curve area according to the direction of the intraocular astigmatism, so that the cornea shaped by the base curve area has a prescribed astigmatism, and the prescribed astigmatism can compensate for the intraocular astigmatism; Obtaining the shape of the corneal region where the adaptation arc zone is located, that is, the region where the corneal adaptation arc zone is located; Determine the curvature radius parameter and direction parameter of the corneal adaptation arc zone according to the shape of the area where the corneal adaptation arc zone is located; The angle between the direction parameter of the base arc area and the direction parameter of the adaptation arc area is determined.

15. The method for manufacturing orthokeratology lenses according to claim 14, characterized in that: The prescribed astigmatism is substantially the same in magnitude as the intraocular astigmatism, but opposite in direction.

16. The method for manufacturing orthokeratology lenses according to claim 14, characterized in that: The curvature radius parameter includes a curvature radius in a flat K direction and a curvature radius in a steep K direction, and the flat K direction or the steep K direction is used as the direction parameter.

17. A corneal reshaping lens, the corneal reshaping lens having an inner surface facing the cornea of ​​a human eye when worn, the inner surface comprising a base curve area located in the center, the base curve area having a toric shape, characterized in that: The base curve area is configured so that the cornea shaped by the base curve area has a specified astigmatism, and the specified astigmatism can compensate for the intraocular astigmatism, which is the vector difference between the whole eye astigmatism and the corneal front surface astigmatism.

18. The orthokeratology lens according to claim 17, characterized in that: The base arc region extends in a sine curve shape or a cosine curve shape in the circumferential direction.

19. The orthokeratology lens according to claim 17, characterized in that: The inner surface further includes an adapting arc area located at the outer peripheral side of the base arc area, and the adapting arc area has a toroidal surface shape.

20. The orthokeratology lens according to claim 19, characterized in that: An included angle α is formed between the toroidal surface shape of the base arc area and the toroidal surface shape of the matching arc area, and 0°≤α≤180°.

21. The orthokeratology lens according to claim 17, characterized in that: For the base curve area, the direction with the largest radius of curvature is called the flat K direction, and the radius of curvature is recorded as R1, and the direction with the smallest radius of curvature is called the steep K direction, and the radius of curvature is recorded as R2, wherein the directions R1 and R2 are perpendicular to each other, and a three-dimensional coordinate system is established with the center of the base curve of the orthokeratology lens as the vertex, wherein the optical axis direction of the orthokeratology lens is the Z axis, and the plane perpendicular to the optical axis and passing through the center of the base curve is the base plane, and z is the height of any point on the base curve surface from the base plane, and the surface shape of the base curve area satisfies the formula: C1 and C2 are the curvatures of the base arc area in the flat K direction and the steep K direction, that is: C1 = 1 / R1, C2 = 1 / R2, (r, θ) is the polar coordinate of any point on the base arc surface projected onto the base plane, and the polar coordinate takes the center of the base arc as the center of the circle and the steep K direction as the polar axis.

22. The orthokeratology lens according to claim 21, characterized in that: The curvature radius R1 of the base arc zone in the flat K direction is 6.00-10.50 mm, 7.00-10.00 mm or 7.50-9.50 mm, and the curvature radius R2 in the steep K direction is 5.42-10.26 mm, 6.23-9.78 mm or 6.62-9.30 mm.

23. The orthokeratology lens according to claim 21, characterized in that: The diameter of the base arc area in the flat K direction is 4.5-8.0 mm, 5.0-7.0 mm or 5.2-6.5 mm.

24. The orthokeratology lens according to claim 21, characterized in that: The height difference between the flat K-direction surface height and the steep K-direction surface height of the base arc region at a diameter of 3.0 mm is 10.7 to 101.8 μm, 10.7 to 75.8 μm or 10.7 to 50.2 μm.

25. The orthokeratology lens according to claim 19 or 20, characterized in that: The curvature radius of the adaptation arc zone in the flat K direction is 6.00-9.50 mm, 6.50-9.00 mm or 7.00-8.50 mm, and the curvature radius in the steep K direction is 5.42-9.43 mm, 5.83-8.94 mm or 6.23-8.45 mm.

Images