Corneal molding lens

Abstract

The present application provides a kind of orthokeratology lens, which includes the inner surface facing the cornea of human eye when wearing, the inner surface includes the base curve area in the center and the reverse curve area on the peripheral side of the base curve area, the base curve area includes: the first base curve area in the center of the base curve area, the curvature of the central side part of the first base curve area is less than the curvature of the peripheral side part;The second base curve area is located on the peripheral side of the first base curve area and is adjacent to the reverse curve area, and the curvature of the central side part of the second base curve area is greater than the curvature of the peripheral side part. With the above structure, the peripheral defocus of the entrance pupil area and the peripheral defocus of the bullseye ring can be improved at the same time, and myopia can be effectively controlled.

Description

Technical Field

[0001] The present invention relates to a corneal reshaping lens. Background Art

[0002] Rigid gas permeable corneal contact lenses for orthokeratology (referred to as orthokeratology lenses) are a reversible, non-surgical refractive correction product.

[0003] Orthokeratology lenses are generally composed of several concentric arc areas, including a base arc area, an inversion arc area, a positioning area, etc., which reshape the cornea through the principle of inverse geometry. The so-called inverse geometry specifically means that the base arc area and the inversion arc area are not in direct contact with the cornea. There is a gap between these two areas and the cornea, while the positioning area is in contact with the cornea. After wearing, the special shape of the inner surface of the orthokeratology lens (sometimes also referred to as the lens in this manual) causes a layer of unevenly distributed tears to be sandwiched between the lens and the cornea. The fluid mechanics of the tears pulls the epithelial cells in the central part of the cornea toward the mid-peripheral part located on the outer side of the central part of the cornea; at the same time, when the eyes are closed, the eyelids exert pressure on the lens. Under the action of this pressure, the central part of the lens exerts a certain pressure on the cornea below it. These two effects cause the central curvature of the cornea to flatten, the cornea is reshaped, the refractive state of the human eye changes compared to before reshaping, and the imaging point of the object moves closer to the retina to achieve the correction of myopia.

[0004] Some orthokeratology lenses have a spherical base curve area. The base curve area is composed of a single spherical surface. The base curve area curvature radius is determined by the corneal K value and myopia. The specific relationship is as follows:

[0005]

[0006] Among them, r is the curvature radius of the spherical base curve, K is the corneal K value, D is the myopia degree, and F is the adjustment coefficient.

[0007] Clinical studies have found that wearing orthokeratology lenses with a spherical base curve can not only correct myopia but also slow the growth of the eye axis in some adolescents, thereby controlling the progression of myopia. Clinical research results show that the mechanism of action of orthokeratology lenses is the peripheral defocus that causes myopia after wearing them.

[0008] However, orthokeratology lenses with a spherical base curve are not 100% effective in controlling myopia. They cannot effectively control myopia in every patient, but only benefit some patients by controlling myopia progression. This is because the base curve is a single sphere, and the corneal K value and myopia degree vary from patient to patient, resulting in varying degrees of myopic peripheral defocus after orthokeratology. Patients with higher corneal K values ​​and myopia degrees experience greater myopic peripheral defocus after orthokeratology, and a greater chance of achieving effective myopia control.

[0009] In addition to orthokeratology lenses with a base curve area of ​​a single sphere, there is also a type of orthokeratology lens in the prior art with a base curve area divided into multiple areas, for example, see Patent Documents 1-4.

[0010] Patent Document 1 discloses a base curve region comprising multiple regions with different curvature radii, so as to correct both ametropia and presbyopia. However, this design is ineffective in improving peripheral defocus.

[0011] In addition, after wearing orthokeratology lenses, the peripheral defocus of the human eye that causes myopia includes two parts: one is the peripheral defocus of the entrance pupil area, and the other is the peripheral defocus of the bull's eye ring.

[0012] Patent Document 2 describes a gradually steepening base curve design. Compared to a single spherical base curve, this improves defocus around the entrance pupil, but does not improve defocus around the bull's-eye ring. Patent Document 3 describes a gradually flattening base curve design, which improves defocus around the bull's-eye ring, but reduces defocus around the entrance pupil.

[0013] Therefore, there is still room for improvement in the existing technology in terms of how to effectively improve peripheral defocus and effectively control myopia.

[0014] Patent Document 1: CN201711278012.0

[0015] Patent Document 2: CN201510441201.X

[0016] Patent Document 3: CN202020791228.8 Summary of the Invention

[0017] The present invention proposes a corneal reshaping lens that can provide a greater myopic peripheral defocus for the human eye, correct myopia, and improve the efficiency of myopia control.

[0018] The present invention provides a corneal reshaping lens, which includes an inner surface facing the human cornea when worn, and the inner surface includes a base curve area located in the center and an inversion curve area located on the peripheral side of the base curve area. The base curve area includes: a first base curve area, located in the center of the base curve area, and the curvature of the central side part of the first base curve area is smaller than the curvature of the peripheral side part; a second base curve area, located on the peripheral side of the first base curve area and adjacent to the inversion curve area, and the curvature of the central side part of the second base curve area is greater than the curvature of the peripheral side part.

[0019] When using a corneal reshaping lens with the above structure, the degree of curvature of the central side portion of the first base curve zone located in the center is smaller than the degree of curvature of the peripheral side portion, thereby improving the peripheral defocus of the entrance pupil area. Since the degree of curvature of the central side portion of the second base curve zone adjacent to the reversal arc zone is greater than the degree of curvature of the peripheral side portion, the peripheral defocus of the bull's eye ring can be improved. In this way, the peripheral defocus of the entrance pupil area and the peripheral defocus of the bull's eye ring can be improved at the same time, thereby improving the efficiency of myopia control.

[0020] Optionally, the first base arc region is composed of one aspherical arc segment, or is composed of multiple first arc segments, and the multiple first arc segments include spherical arc segments and / or aspherical arc segments.

[0021] Optionally, the second base arc area is composed of one spherical arc segment or an aspherical arc segment, or is composed of multiple second arc segments, and the multiple second arc segments include spherical arc segments and / or aspherical arc segments.

[0022] Optionally, the first proportional factor of the first base curve region satisfies the following relationship:

[0023] η mn <1

[0024]

[0025] Among them, the first proportional factor η mn is the ratio of the equivalent curvature radius r at points m and n on the first base curve area, point m is the outer edge point of the first base curve area, point n is the point close to the center, r m is the equivalent curvature radius of point m, r n is the equivalent radius of curvature of point n.

[0026] Optionally, the diameter d of point n n =0.01mm.

[0027] Optionally, the first scaling factor η mn Satisfy the following relationship: 0.790≤η mn <1, or 0.891≤η mn ≤0.999, or 0.967≤η mn ≤0.997.

[0028] Optionally, the first base arc region includes a plurality of first arc segments, and the second proportional factor η of the first base arc region is ij The following relationship is satisfied:

[0029] η mn ≤η ij <1

[0030] η ij =rj / r i

[0031] Among them, the second proportional factor η ij is the ratio of the equivalent curvature radii at points i and j, where i and j are any two points on the multiple first arc segments, and can be any two points on the same first arc segment or any two points on different first arc segments, and satisfy the following relationship:

[0032] d i <d j

[0033] Among them, d i is the diameter at point i, d j is the diameter at point j.

[0034] Optionally, the first base arc region includes a plurality of first arc segments, and η of each of the first arc segments is ij different.

[0035] Optionally, the first base arc region includes a plurality of first arc segments, and η of each of the first arc segments is ij It changes gradually from inside to outside along the radial direction.

[0036] Optionally, the third proportional factor δ of the second base curve region sm The following relations are satisfied:

[0037] δ sm >1

[0038]

[0039] Among them, δ sm is the ratio of the equivalent curvature radius r at points s and m, where s is the connection point between the second base arc region and the reverse arc region, and r s is the equivalent curvature radius at point s, r m is the equivalent radius of curvature at point m.

[0040] Optionally, the third proportional factor δ sm Satisfies: 1 < δ sm ≤2.239, or 1.001≤δ sm ≤1.960, or 1.002≤δ sm ≤1.605.

[0041] Optionally, the second base arc region includes a plurality of second arc segments, and the fourth proportional factor δ of the second base arc region is pq The following relationship is satisfied:

[0042] δ pq =r q / r p

[0043] 1<δ pq ≤δ sm

[0044] Among them, the fourth proportional factor δ pq is the ratio of the equivalent curvature radii at points p and q, where p and q are any two points on the plurality of second arc segments, and may be any two points on the same second arc segment or any two points on different second arc segments, and satisfy,

[0045] d p <d q ,

[0046] Among them, d p is the diameter at point p, d p is the diameter at point q.

[0047] Optionally, the second base arc region includes a plurality of second arc segments, and the δ of each second arc segment is pq different.

[0048] Optionally, the second base arc region includes a plurality of second arc segments, and the δ of each second arc segment is pq It changes gradually from inside to outside along the radial direction.

[0049] Optionally, the surface expression of the aspherical shape is:

[0050]

[0051] It is the expression of the curve of the aspheric generatrix on the xy plane, c is the curvature of the basic sphere in the first base arc area, Q is the aspheric coefficient, A 2i is the aspheric surface high-order coefficient, each point on the aspheric surface shape is obtained by rotating the curve around the coordinate axis y, and the aspheric surface adopts the Q value, or the Q value is used in combination with the high-order coefficient.

[0052] Optionally, the surface expression of the spherical shape is:

[0053] (xa) 2 +(yb) 2 =R 2

[0054] It is an expression of the curve of the spherical generatrix on the xy plane, (a, b) is the coordinate of the center of the circle, R is the radius of curvature of the circle, and each point on the spherical shape is obtained by rotating the curve around the coordinate axis y.

[0055] Optionally, the equivalent radius of curvature at a certain point is calculated as follows:

[0056]

[0057] Where d is the diameter of the point, h is the sagittal height of the point, and r is the equivalent radius of curvature of the point.

[0058] Optionally, the curvature radius of the first base arc region is 7.0-11.0 mm.

[0059] Optionally, the first base arc area is circular, with a diameter of 2.0 to 5.0 mm, or 2.5 to 4.5 mm, or 3.0 to 4.0 mm.

[0060] Optionally, the second base arc area is in the shape of a circular ring, with a diameter of 1.0 to 3.0 mm, or 1.0 to 2.5 mm, or 1.0 to 2.0 mm.

[0061] Definition of terms

[0062] Unless otherwise specified, the following definitions apply to the terms used in this specification.

[0063] 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 the anterior surface of the cornea into its shape. After shaping, this area of ​​the cornea is the optical zone and plays a role in optical imaging.

[0064] The reversal arc zone (RC) is the second area closely connected to the base arc zone. It plays the role of connecting the base arc zone and the adaptation arc zone, forming a gap between the orthokeratology lens and the anterior surface of the cornea, which plays the role of storing tears and promoting tear circulation.

[0065] The adaptation arc zone (AC), also known as the positioning arc zone, matching arc zone, etc., is adjacent to the inversion arc zone. This area matches the shape of the cornea and plays a positioning role.

[0066] 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. It is generally flatter than the fitting arc zone and presents a certain tilt angle with the corneal surface to ensure the exchange and circulation of tears and oxygen around the cornea and the orthokeratology lens.

[0067] The diameter w refers to the width along the radial direction.

[0068] The term "basic sphere" refers to the sphere determined by the corneal K value and the myopia degree, and the radius of curvature is r = 337.5 / (K+D+F).

[0069] The terms "steep" and "flat" refer to descriptions of the degree of size of the equivalent radius of curvature of a lens. For example, for the purposes of this application, "steep" means that the absolute value of the equivalent radius of curvature of the lens is smaller than the absolute value of the radius of curvature of the base sphere, and "flat" means that the absolute value of the equivalent radius of curvature of the lens is larger than the absolute value of the radius of curvature of the base sphere. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 The diagram below shows the calculation method of the equivalent radius of curvature, where O is the vertex of the aspheric surface, and r m is the equivalent radius of curvature, d is the diameter at a certain point, h is the sagittal height at a certain point, that is, the vertical distance from the point to the vertex, and w represents the diameter width. Figure 1 The base arc area is shown, so the diameter width is equal to the radius;

[0071] Figure 2 It is a structural schematic diagram of a corneal reshaping lens involved in a specific embodiment;

[0072] Figure 3 Schematic diagram illustrating the technical effect of orthokeratology lenses in a specific embodiment of the present invention;

[0073] Figure 4 Schematic diagram of orthokeratology lens in which the first base curve area and the second base curve area are composed of multiple arc segments involved in other embodiments;

[0074] Figure 5 Schematic diagram of a corneal reshaping lens in which the first base curve area is composed of three arc segments in other embodiments. The top curve close to the x-axis represents the basic sphere, and the three curves below are specific embodiments of the present invention. Compared with the basic sphere, the three curves are gradually steeper, but η mn Same, η ij different;

[0075] Figure 6 is a schematic diagram of a corneal reshaping lens in which the second base curve area is composed of three arc segments in another embodiment, wherein the three curves δ sm Same, δ pq different. DETAILED DESCRIPTION

[0076] Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0077] The orthokeratology lens of this embodiment is used to correct myopia, and includes an inner surface facing the human cornea when worn and an outer surface opposite to the inner surface. The inner surface includes a base curve area, a reversal curve area, a positioning curve area and an edge curve area. Figure 2 FIG. 1 is a schematic structural diagram of a corneal reshaping lens according to the present embodiment, wherein 10 is the base curve area, 20 is the inversion curve area, 30 is the positioning curve area, and 40 is the side curve area.

[0078] As mentioned above, after wearing orthokeratology lenses, the peripheral defocus of the human eye that causes myopia includes two parts: one is the peripheral defocus of the entrance pupil area, and the other is the peripheral defocus of the bull's eye ring.

[0079] The peripheral defocus of the entrance pupil area is the defocus within the pupil range. The average pupil diameter is 3 to 4 mm. The cornea in this area is most closely fitted to the base curve area, and the shape of the cornea after shaping is basically the same as the shape of the base curve area. In order to improve the peripheral defocus of the entrance pupil area, in this embodiment, the central area of ​​the base curve area is designed to have a smaller curvature radius than the center, and the surface shape becomes steeper and steeper, so that the refractive power increases with the increase of the aperture, providing the human eye with a controllable degree of myopic defocus.

[0080] Bull's eye peripheral defocus, that is, the area of ​​the cornea that has been reshaped by the inversion arc zone can bring a large amount of peripheral defocus to the human eye. This area of ​​the cornea is called the "bull's eye ring" area, and accordingly, the peripheral defocus brought by this area is called bull's eye peripheral defocus. The size of the bull's eye peripheral defocus depends on the traction of the inversion arc zone on the epithelial cells in the center of the cornea, and the size of the traction depends on the sagittal height difference of the inversion arc zone. The sagittal height difference of the inversion arc zone refers to the difference between the sagittal height of the starting point and the sagittal height of the end point of the inversion arc zone (the sagittal height difference of the inversion arc zone can also be understood as the height of the inversion arc zone in the direction of the optical axis), where the starting point is the end point of the base arc zone, that is, the point at the outer edge of the base arc zone, the connection point between the base arc zone and the inversion arc, and the end point is the starting point of the positioning arc (fitting arc). Sagittal height refers to the difference between the position of the point on the lens and the vertex of the orthokeratology lens ( Figure 3 The height difference between O).

[0081] The greater the sagittal height difference in the inversion arc zone, the greater the fluid force created by the tear layer between the lens and the cornea, the more corneal epithelial cells migrate toward the periphery, and the steeper the reshaped corneal surface. This increases refractive power with increasing aperture, providing a controlled degree of myopic defocus. To increase the sagittal height difference in the inversion arc zone, in this embodiment, the outermost portion of the base curve zone is designed with a greater radius of curvature at the periphery than at the center.

[0082] like Figure 2 As shown, in this embodiment, the base curve region 10 includes two regions, namely, a first base curve region 1 and a second base curve region 2. The first base curve region 1 is located at the center of the orthokeratology lens and is a circular region. As another embodiment, the first base curve region 1 can also be non-circular, such as an elliptical or irregular shape. The second base curve region 2 is located on the outer side of the first base curve region, adjacent to the inversion curve region 20, and is an annular region. In addition, as another embodiment, the second base curve region 2 can also be non-circular, such as an elliptical or irregular shape.

[0083] The diameter of the first base arc region is 2.0 to 5.0 mm, preferably 2.5 to 4.5 mm, and more preferably 3.0 to 4.0 mm.

[0084] The first base arc region is composed of one arc segment or multiple arc segments. When composed of one arc segment, the arc segment is aspherical. When composed of multiple arc segments, the multiple arc segments can all be spherical or aspherical, or can include both spherical and aspherical arc segments. The curvature of the central portion of the first base arc region 1 is less than that of the peripheral portion.

[0085] The surface expression of the above-mentioned aspherical shape can be:

[0086]

[0087] It is the expression of the curve of the aspheric generatrix on the xy plane, c is the curvature of the basic sphere, Q is the aspheric coefficient, A 2i is the high-order coefficient of the aspheric surface. Each point on the aspheric surface shape is obtained by rotating the curve around the y-axis. The aspheric surface adopts the Q value, or the Q value is used in combination with the high-order coefficient.

[0088] In addition, the surface expression of the above spherical shape can be:

[0089] (xa) 2 +(yb) 2 =R 2 (2)

[0090] The above formula is the expression of the curve of the spherical generatrix on the xy plane, (a, b) is the coordinate of the center of the circle, and R is the radius of curvature of the circle.

[0091] As an alternative, the degree of curvature can be determined by a ratio factor η between the equivalent radii of curvature of the central side portion and the peripheral side portion. mn Define, the proportional factor η mn <1. Where η mn is the ratio of the equivalent curvature radius r at points m and n on the first base curve area, point m is a point on the outer edge of the first base curve area (in this embodiment, it is the connection point with the second base curve area), d m is the diameter of the first base arc area, point n is the point close to the center, d n =0.01mm:

[0092]

[0093] Among them, r m is the equivalent radius of curvature at point m, r n is the equivalent radius of curvature at point n.

[0094] Reference Figure 1 , the calculation method of the equivalent curvature radius is as follows:

[0095]

[0096] Among them, d is the diameter of a certain point, h is the sagitta of a certain point, and r is the equivalent curvature radius of a certain point.

[0097] It should be noted that the equivalent curvature radius is related to d and h, and actually describes the positional relationship. For example, taking an arc segment in the shape of a spherical surface as an example, its curvature radius is 7.0, the xy coordinates of the starting point are (2, 1), and the equivalent curvature radius of this point is r = ((2 * 2) 2 + 4 * 1 2 ) / (8 * 1) = 2.5.

[0098] Scale factor η [[ID=1 3]] mn can be 0.785 ≤ η mn < 1, preferably 0.887 ≤ η mn ≤ 0.999, more preferably 0.965 ≤ η mn ≤ 0.997.

[0099] Furthermore, if the first base arc region is composed of at least two arc segments in the shape of a spherical surface or an aspherical surface, the scale factor η ij can be used to further limit each arc segment. i and j are any two points on at least two arc segments, which can be any two points on the same arc segment or any two points on different arc segments, and satisfy di < dj. The scale factor η ij = r j / r i , η mn ≤ η ij < 1. As another way, the η of each arc segment ij can be different. In addition, the η of each arc segment ij can gradually change from the inside to the outside along the radial direction.

[0100] Through the above scale factors η mn and η ij , it can be limited that the bending degree of the first base arc region shows a gradually steep trend. The bending degrees of each arc segment can be different from each other.

[0101] The radial width of the second base arc region can be 1.0 - 3.0 mm, preferably 1.0 - 2.5 mm, and more preferably 1.0 - 2.0 mm.

[0102] The second base arc region is composed of one arc segment or multiple arc segments. When it is composed of one arc segment, this arc segment can be in the shape of a spherical surface or an aspherical surface. When it is composed of multiple arc segments, the multiple arc segments can all be in the shape of a spherical surface or an aspherical surface, or can include both arc segments in the shape of a spherical surface and arc segments in the shape of an aspherical surface. The bending degree of the part of the second base arc region close to the center side is greater than that of the peripheral side part.

[0103] Here, the surface shape expression of the aspherical surface of the second base curve area is the same as equation (1), and the surface shape expression of the spherical surface of the second base curve area is the same as equation (2).

[0104] As an optional method, the curvature of the second base curve region is proportional to the equivalent curvature radius of the central side portion and the peripheral side portion by a factor δ sm Limit, the scaling factor δ sm >1.δ sm is the ratio of the curvature radius r at points s and m, where s is the connection point between the second base arc area and the reversal arc area, and d s is the base arc diameter:

[0105]

[0106] The scaling factor δ sm Can be 1<δ sm ≤2.239, preferably 1.001≤δ sm ≤1.960, more preferably 1.002≤δ sm ≤1.605.

[0107] Furthermore, if the second base arc region is composed of multiple spherical or aspherical arc segments, the scaling factor δ pq Each arc segment is further limited, p and q are any two points on multiple arc segments, which can be any two points on the same arc segment or any two points on different arc segments, and satisfy d p <d q , the above scaling factor δ pq =rq / rp, 1<δ pq ≤δ sm . The δ of each arc segment pq Can be different. In addition, the δ of each arc segment pq It changes gradually from inside to outside along the radial direction.

[0108] By the above scaling factor δ sm and δ pq , it can be defined that the curvature of the second base arc region is a trend of gradually flattening. The curvature of each arc segment can be different from each other.

[0109] Technical Effects

[0110] The shaping mechanism of the base curve center and base curve periphery of orthokeratology lenses (OK lenses) is different. The purpose of dividing the base curve into multiple zones mentioned in Patent Document 1 is to correct refractive errors while combining presbyopia correction. Its structure has no effect on improving peripheral defocus. The base curve zone mentioned in Patent Document 2 is a gradually steepening design. Although it can improve the peripheral defocus of the entrance pupil area, the peripheral defocus of the bull's eye ring is not improved. The base curve zone mentioned in Patent Document 3 is a gradually flattening design. Although it can improve the peripheral defocus of the bull's eye ring, the peripheral defocus of the entrance pupil area is reduced.

[0111] Figure 3 This is a schematic diagram of the technical effect of the orthokeratology lens of the present invention, wherein the horizontal axis is the size of the pupil radius of the human eye, and the vertical axis is the refractive power distribution formed by the human eye wearing the orthokeratology lens. Figure 3 As shown, unlike the techniques in Patent Documents 1-3, the orthokeratology lens of the above embodiment of the present invention improves the peripheral defocus of the entrance pupil area due to the increasingly steep structure of the most central area of ​​the base curve, while the peripheral area of ​​the base curve is increasingly flat, thereby improving the peripheral defocus of the bull's eye ring. Thus, the orthokeratology lens can simultaneously improve the peripheral defocus of the entrance pupil area and the bull's eye ring. Moreover, the peripheral defocus amount formed increases gradually with the radial increase of the aperture, without sudden changes.

[0112] The above description uses a two-zone structure as an example. However, the present invention is not limited to this. The base arc region can also have multiple zones. For example, the central region becomes increasingly steeper, while the outermost region becomes increasingly flatter. The central and outermost regions are connected by one or more connecting zones, which serve as transition zones between the central and outermost regions. As long as the base arc region has a structure that is first steep and then flat, it is within the scope of protection of the present invention.

[0113] Figure 4 This is a schematic diagram of a corneal reshaping lens in which the first base curve area and the second base curve area are composed of multiple arc segments involved in other embodiments, wherein 1 indicates that the arc segment belongs to the first base curve area, and 2 indicates that the arc segment belongs to the second base curve area. Figure 4 In (a), the first base arc area consists of a single arc segment, and the second base arc area consists of a single arc segment. In (b), the first base arc area consists of two arc segments, and the second base arc area consists of a single arc segment. In (c), the first base arc area consists of 4 arc segments, and the second base arc area consists of 2 arc segments. In (d), the first base arc area consists of 2 arc segments, and the second base arc area consists of 2 arc segments.

[0114] Figure 5FIG. 1 is a schematic diagram of a corneal reshaping lens with three arc segments in the first base curve area involved in another embodiment. In the figure, the uppermost curve close to the x-axis represents the basic sphere, and the three curves below represent the three surface shapes of the first base curve area in a specific embodiment of the present invention. These three surface shapes are gradually steeper than the basic sphere, but η mn Same, η ij different.

[0115] Figure 6 Schematic diagram of a corneal reshaping lens in which the second base curve area is composed of three arc segments in another embodiment, wherein the three curves represent three surface shapes of the second base curve area. sm Same, δ pq different.

[0116] Some specific embodiments of the present invention are provided below, please refer to Tables 1-3 below.

[0117] Table 1 Example 1 The first base arc area and the second base arc area are both 1 arc segment

[0118] Table 2 Example 2 The first base arc region and / or the second base arc region are multiple arc segments

[0119] In the present invention, there are multiple possible combinations of specific implementation methods of orthokeratology lenses. Taking Table 2 as an example, the first base curve area can use any one of the implementation methods 1-3 in Table 2, and the second base curve area can use any one of the implementation methods 1-3 in Table 2. Thus, there are 9 combinations.

[0120] Table 3 Example 3 The first base arc region and / or the second base arc region are multiple arc segments

[0121] As can be seen from the above embodiments, the first base arc region and the second base arc region can be composed of one or more arc segments, and can be a combination of spherical and aspherical surfaces, as long as the curvature of the central portion of the first base arc region is less than the curvature of the peripheral portion (η mn <1), the curvature of the second base arc region near the center is greater than that of the peripheral side (δ sm >1).

[0122] Other embodiments provided by the present application are described below. In the following description, parts identical to those in the above embodiments are omitted or briefly described.

[0123] In this embodiment, if Figure 2As shown, the base arc region includes two regions, which are the first base arc region and the second base arc region from the center outward.

[0124] The diameter of the first base arc region is 2.0 to 5.0 mm, preferably 2.5 to 4.5 mm, and more preferably 3.0 to 4.0 mm.

[0125] The first base arc region may be composed of one arc segment or multiple arc segments. When composed of one arc segment, the arc segment is aspherical. When composed of multiple arc segments, the arc segments may all be spherical, all aspherical, or a combination of spherical and aspherical surfaces. The curvature of the central portion of the first base arc region is less than that of the peripheral portion.

[0126] The degree of curvature can be defined by the height difference h1 between the base arc and the base sphere at the same diameter, where the height difference h1>0.

[0127] h1=h 1A -h S

[0128] Among them, h 1A is the sag height of the first base arc area, h S is the sag of the base sphere.

[0129] When the first base arc area consists of one arc segment, it is only necessary to calculate the sagittal height difference at the diameter of the arc segment.

[0130] When the first base arc area consists of multiple arc segments, it is necessary to calculate the sagittal height difference at the diameter of each arc segment.

[0131] The sag of an aspheric surface can be obtained from the aspheric expression:

[0132]

[0133] It is an expression of the curve of the aspheric generatrix on the xy plane, |y| is the vector height value, c is the curvature of the basic sphere, Q is the aspheric coefficient, A2i is the aspheric high-order coefficient, and each point on the aspheric shape is obtained by rotating the curve around the y-axis. The aspheric surface adopts the Q value, or the Q value is used in combination with the high-order coefficient.

[0134] The sag of a sphere can be obtained from the spherical expression:

[0135] (xa) 2 +(yb) 2 =R 2 (2)

[0136] It is an expression of the curve of the spherical generatrix on the xy plane, |y| is the vector height value, (a, b) is the coordinate of the center of the circle, R is the radius of curvature of the circle, and each point on the spherical shape is obtained by rotating the curve around the coordinate axis y.

[0137] The sagittal height h of the base sphere s It can be derived from the following formula:

[0138]

[0139] Among them, r s is the radius of curvature of the base sphere, and d is the diameter. When calculating the sagittal difference, the difference in sagittal height between the base arc area and the base sphere at the same diameter is calculated.

[0140] The diameter of the second base arc region may be 1.0 to 3.0 mm, preferably 1.0 to 2.5 mm, and more preferably 1.0 to 2.0 mm.

[0141] The second base arc region is composed of one or more spherical arc segments or aspherical arc segments. The curvature of the central side portion of the second base arc region is greater than the curvature of the peripheral side portion.

[0142] As an optional manner, the degree of curvature is defined by a sagittal height difference h2 between the base arc and the base sphere at the same diameter, wherein the sagittal height difference h2<0.

[0143] h2=h 2A -h S

[0144] Among them, h 2A is the sag height of the second base arc area, h S is the sag of the base sphere.

[0145] When the second base arc area consists of one arc segment, it is only necessary to calculate the sagittal height difference at the diameter of the arc segment.

[0146] When the second base arc area consists of multiple arc segments, it is necessary to calculate the sagittal height difference at the diameter of each arc segment.

[0147] The calculation method of the arrow height is shown in formula (1) and formula (2).

[0148] Several specific embodiments derived from the concept of this embodiment are given below.

[0149] Table 4 Parameter examples of the first base arc area

[0150]

[0151] Table 5 Parameter examples of the second base arc area

[0152]

[0153] In this embodiment, there are multiple possible combinations of specific forms of corneal refractive therapy lenses. Taking Tables 4 and 5 above as examples, the first base curve area can adopt any one of the methods 1-4 in Table 4 above, and the second base curve area can adopt any one of the implementation methods 1-4 in Table 5 above. Thus, there are 16 combinations.

[0154] It should be noted that, in this embodiment, the specific implementation methods of the arc segments of the first base arc area and the second base arc area are not limited to those listed in Tables 4 and 5 above. In this embodiment, the first base arc area and the second base arc area can be composed of one or more arc segments, which can be a combination of spherical and aspherical surfaces, as long as the sagittal height difference h1 of the first base arc area is greater than 0 and the sagittal height difference h2 of the second base arc area is less than 0, which helps to achieve that the curvature of the central part of the first base arc area is less than that of the peripheral part (h>0), and the curvature of the second base arc area near the central part is greater than that of the peripheral part (h<0).

[0155] According to the concept of this embodiment, the following solution can be obtained.

[0156] A corneal reshaping lens, comprising an inner surface facing the human cornea when worn and an outer surface opposite to the inner surface, wherein the inner surface comprises a base curve area located in the center and an inversion curve area located on the periphery of the base curve area, wherein the base curve area comprises: a first base curve area located in the center of the base curve area, wherein the curvature of the central side portion of the first base curve area is smaller than that of the peripheral side portion; a second base curve area located on the periphery of the first base curve area and adjacent to the inversion curve area, wherein the curvature of the central side portion of the second base curve area is larger than that of the peripheral side portion. The difference in sagittal height h1 between the base curve area and its base sphere at the same diameter of the first base curve area is greater than 0; the difference in sagittal height h2 between the base curve and the base sphere at the same diameter of the second base curve area is less than 0;

[0157] Where h1 = h 1A -h S , h 1A is the sag height of the first base arc area, h S is the sagittal height of the base sphere; h2=h 2A -h S , h 2A is the sag height of the second base arc area, h S is the sag of the base sphere.

[0158] By adopting this technical solution, it is possible to achieve that the curvature of the central portion of the first base arc area is smaller than that of the peripheral portion, and the curvature of the second base arc area near the central portion is larger than that of the peripheral portion. Figure 3 As shown and described above, the myopia control effectiveness can be improved.

[0159] Optionally, the sagittal height difference of any arc segment increases from inside to outside along the radial direction. Specifically, any two points ij on any arc segment included in the first base arc area satisfy: di<dj, and h1i<h1j.

[0160] Optionally, the first base arc region is composed of at least two arc segments, and the diameter h1 of each arc segment increases from inside to outside along the radial direction.

[0161] Optionally, the first base arc region includes at least three arc segments, and along the radial direction, the diameter of the arc segment located at the radially outermost end is h 1外 Greater than h at the diameter of the arc segment located at the radial innermost end 1内 , h1>0 at the diameter of the other arc segments between the two.

[0162] Optionally, the sagittal height difference of any arc segment decreases from inside to outside along the radial direction. Specifically, any two points pq on any arc segment included in the second base arc area satisfy: dp<dq, and h2p>h2q.

[0163] Optionally, the second base arc region is composed of at least two aspherical or spherical arc segments, and the sagittal height difference h2 at the diameter of each arc segment decreases from inside to outside along the radial direction.

[0164] Optionally, the second base arc region includes at least three aspherical or spherical arcs, and along the radial direction, the diameter of the arc segment located at the radially outermost end is h 2外 Smaller than h at the diameter of the arc segment located at the radial innermost end 1内 , h2<0 at the diameter of the other arc segments between the two.

[0165] Optionally, the first base curve region includes at least one spherical or aspherical arc.

[0166] Optionally, the second base curve region includes at least one spherical or aspherical arc.

[0167] The sag of an aspheric surface can be obtained from the aspheric expression:

[0168]

[0169] It is an expression of the curve of the aspheric generatrix on the xy plane, |y| is the vector height value, c is the curvature of the basic sphere, Q is the aspheric coefficient, A2i is the aspheric high-order coefficient, and each point on the aspheric shape is obtained by rotating the curve around the y-axis. The aspheric surface adopts the Q value, or the Q value is used in combination with the high-order coefficient.

[0170] The sag of a sphere can be obtained from the following formula:

[0171] (xa)2 +(yb) 2 =R 2

[0172] It is an expression of the curve of the spherical generatrix on the xy plane, |y| is the vector height value, (a, b) is the coordinate of the center of the circle, R is the radius of curvature of the circle, and each point on the spherical shape is obtained by rotating the curve around the coordinate axis y.

[0173] The sagittal height h of the base sphere s It can be derived from the following formula:

[0174]

[0175] Among them, r s is the radius of curvature of the base sphere, and d is the diameter.

[0176] The curvature radius of the first base curve region may be 7.0 to 11.0 mm.

[0177] The diameter of the first base arc region may be 2.0-5.0 mm, or 2.5-4.5 mm, or 3.0-4.0 mm.

[0178] The diameter width of the second base arc region may be 1.0 to 3.0 mm, or 1.0 to 2.5 mm, or 1.0 to 2.0 mm.

[0179] 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 principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A corneal reshaping lens, comprising an inner surface facing the cornea of ​​a human eye when worn, wherein the inner surface comprises a base curve area located in the center, an inversion curve area located on the periphery of the base curve area, and an adaptation curve area located on the periphery of the inversion curve area, characterized in that: The base arc region includes: The first base arc region is located at the center of the base arc region. The curvature of the central side portion of the first base arc region is smaller than the curvature of the peripheral side portion, so that the first proportional factor of the first base arc region satisfies the following relationship: or mn <1 Among them, the first proportional factor η mn is the ratio of the equivalent curvature radius r at points m and n on the first base curve area, point m is the outer edge point of the first base curve area, point n is the point close to the center, r m is the equivalent curvature radius of point m, r n is the equivalent curvature radius of point n; The second base arc region is located on the outer side of the first base arc region and is adjacent to the reverse arc region. The curvature of the central side portion of the second base arc region is greater than the curvature of the peripheral side portion, so that the third proportional factor δ of the second base arc region is sm The following relations are satisfied: d sm >1 Among them, δ sm is the ratio of the equivalent curvature radius r at points s and m, where s is the connection point between the second base arc region and the reverse arc region, and r s is the equivalent curvature radius at point s, r m is the equivalent curvature radius at point m, The calculation method of the equivalent radius of curvature of the above points is as follows: Among them, d is the diameter of the point, that is, twice the vertical distance from the point to the central axis of the base arc area, h is the sagittal height of the point, and r is the curvature radius of the point.

2. The orthokeratology lens according to claim 1, wherein: The first base arc region is composed of one aspherical arc segment, or is composed of a plurality of first arc segments, wherein the plurality of first arc segments include spherical arc segments and / or aspherical arc segments.

3. The orthokeratology lens according to claim 1, wherein: The second base arc region is composed of one spherical arc segment or one aspherical arc segment, or is composed of a plurality of second arc segments, wherein the plurality of second arc segments include spherical arc segments and / or aspherical arc segments.

4. The orthokeratology lens according to claim 1, wherein: Diameter d of point n n =0.01mm.

5. The orthokeratology lens according to claim 1, wherein: The first proportional factor η mn Satisfy the following relationship: 0.790≤η mn <1.

6. The orthokeratology lens according to claim 1, wherein: The first proportional factor η mn Satisfies the following relationship: 0.891≤η mn ≤0.

999.

7. The orthokeratology lens according to claim 1, wherein: The first proportional factor η mn Satisfies the following relationship: 0.967≤η mn ≤0.

997.

8. The orthokeratology lens according to claim 1, wherein: The first base arc region includes a plurality of first arc segments, and the second proportional factor η of the first base arc region ij The following relationship is satisfied: or mn ≤η ij <1 or ij =r j / r i Among them, the second proportional factor η ij is the ratio of the equivalent curvature radii at points i and j, where i and j are any two points on the plurality of first arc segments and satisfy the following relationship: d i <d j Among them, d i is the diameter at point i, d j is the diameter at point j.

9. The orthokeratology lens according to claim 8, characterized in that: The first base arc region includes a plurality of first arc segments, and the η of each of the first arc segments is ij different.

10. The orthokeratology lens according to claim 8, wherein: The first base arc region includes a plurality of first arc segments, and the η of each of the first arc segments is ij It changes gradually from inside to outside along the radial direction.

11. The orthokeratology lens according to claim 10, wherein: The third proportional factor δ sm Satisfies: 1 < δ sm ≤2.

239.

12. The orthokeratology lens according to claim 10, wherein: The third proportional factor δ sm Satisfies: 1.001≤δ sm ≤1.

960.

13. The orthokeratology lens according to claim 10, wherein: The third proportional factor δ sm Satisfies: 1.002≤δ sm ≤1.

605.

14. The orthokeratology lens according to claim 1, wherein: The second base arc region includes a plurality of second arc segments, and the fourth proportional factor δ of the second base arc region pq The following relationship is satisfied: d pq =r q / r p 1<δ pq ≤δ sm Among them, the fourth proportional factor δ pq is the ratio of the equivalent radii of curvature at points p and q, where p and q are any two points on any of the second arc segments and satisfy, d p <d q , Among them, d p is the diameter at point p, d p is the diameter at point q.

15. The orthokeratology lens according to claim 14, wherein: The second base arc region includes a plurality of second arc segments, each of which has a δ pq different.

16. The orthokeratology lens according to claim 14, wherein: The second base arc region includes a plurality of second arc segments, each of which has a δ pq It changes gradually from inside to outside along the radial direction.

17. The orthokeratology lens according to claim 2 or 3, characterized in that: The surface expression of the aspherical shape is: It is the expression of the curve of the aspheric generatrix on the xy plane, c is the curvature of the basic sphere in the first base arc area, Q is the aspheric coefficient, A 2i is the aspheric surface high-order coefficient, each point on the aspheric surface shape is obtained by rotating the curve around the coordinate axis y, and the aspheric surface adopts the Q value, or the Q value is used in combination with the high-order coefficient.

18. The orthokeratology lens according to claim 2 or 3, characterized in that: The surface expression of the spherical shape is: (x-a) 2 +(y-b) 2 =R 2 It is an expression of the curve of the spherical generatrix on the xy plane, (a, b) is the coordinate of the center of the circle, R is the radius of curvature of the circle, and each point on the spherical shape is obtained by rotating the curve around the coordinate axis y.

19. The orthokeratology lens according to any one of claims 1 to 3, characterized in that: The curvature radius of the first base arc region is 7.0-11.0 mm.

20. The orthokeratology lens according to any one of claims 1 to 3, characterized in that: The first base arc area is circular, and the diameter is greater than or equal to 2.0 and less than or equal to 5.0 mm.

21. The orthokeratology lens according to any one of claims 1 to 3, characterized in that: The first base arc area is circular, with a diameter of 2.5 to 4.5 mm.

22. The orthokeratology lens according to any one of claims 1 to 3, characterized in that: The first base arc area is circular, with a diameter of 3.0-4.0 mm.

23. The orthokeratology lens according to any one of claims 1 to 3, characterized in that: The second base arc area is in the shape of a circular ring, with a diameter width of 1.0 to 3.0 mm.

24. The orthokeratology lens according to any one of claims 1 to 3, characterized in that: The second base arc area is in the shape of a circular ring, with a diameter width of 1.0 to 2.5 mm.

25. The orthokeratology lens according to any one of claims 1 to 3, characterized in that: The second base arc area is in the shape of a circular ring, with a diameter width of 1.0 to 2.0 mm.

26. The orthokeratology lens according to any one of claims 1 to 3, characterized in that: The curvature of the central side portion of the first base arc region is smaller than that of the peripheral side portion, so that the curvature of the first base arc region gradually becomes steeper. The curvature of the central side portion of the second base arc region is greater than that of the peripheral side portion, so that the curvature of the second base arc region is gradually flattened. The "steep" mentioned here means that the absolute value of the equivalent radius of curvature of the lens is smaller than the absolute value of the radius of curvature of the basic sphere, and the "flat" mentioned here means that the absolute value of the equivalent radius of curvature of the lens is larger than the absolute value of the radius of curvature of the basic sphere, wherein the "basic sphere" refers to the spherical surface determined by the corneal K value and the myopia degree, and the curvature radius is r=337.5 / (K+D+F), wherein K is the corneal K value, D is the myopia degree, and F is the adjustment coefficient.

27. The orthokeratology lens according to claim 1, wherein: The base curve area is located in the center of the orthokeratology lens and is the inner surface of the optical zone. It is used to compress the front surface of the cornea and shape the front surface of the cornea into its shape.

28. The orthokeratology lens according to claim 1, wherein: The inversion arc area is the second area closely connected to the base arc area, forming a gap between the orthokeratology lens and the front surface of the cornea, which plays a role in storing tears and promoting tear circulation.

29. The orthokeratology lens according to claim 28, wherein: The adaptation arc area is adjacent to the inversion arc area, matches the shape of the cornea, and plays a positioning role.

30. The orthokeratology lens according to claim 29, wherein: It also includes an edge arc area, which is located at the outermost edge of the corneal reshaping lens and is connected to the adaptation arc area. It is flatter than the adaptation arc area and is tilted relative to the corneal surface to ensure the exchange and circulation of tears and oxygen around the cornea and the reshaping lens.

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