CN216792610U

CN216792610U - Myopia prevention and control type corneal contact lens

Info

Publication number: CN216792610U
Application number: CN202220471010.3U
Authority: CN
Inventors: 刘熠; 蔡勇; 尚利如; 崔秀国; 李国丹
Original assignee: Hangzhou Weixiao Medical Technology Co ltd; Zhuhai Weishi Aikangte Pharmaceutical Technology Co ltd; Zhuhai Xigu Medical Technology Co ltd; Shanghai Aikangte Medical Technology Co ltd
Current assignee: Shanghai Aikangte Medical Technology Co ltd
Priority date: 2022-03-03
Filing date: 2022-03-03
Publication date: 2022-06-21
Anticipated expiration: 2032-03-03

Abstract

The utility model describes a myopia prevention and control type corneal contact lens, which is provided with an inner surface facing to a cornea when being worn and an outer surface opposite to the inner surface, wherein the myopia prevention and control type corneal contact lens is provided with a prescription area and an over-prescription area, on an XZ plane formed by taking the rise direction of the myopia prevention and control type corneal contact lens as a Z-axis direction, taking the width direction of the myopia prevention and control type corneal contact lens as an X-axis direction and taking the peak of the outer surface as an origin, X represents the distance between a point on the inner surface, the outer surface or the front surface of the cornea and the Z-axis, and the joint between the prescription area and the over-prescription area is formed into a smooth curve. The utility model can provide the myopia prevention and control type corneal contact lens with high wearing comfort.

Description

Myopia prevention and control type corneal contact lens

Technical Field

The utility model relates to a myopia prevention and control type corneal contact lens.

Background

A rigid oxygen permeable corneal contact lens (RGP) is a contact lens that is safe and effective for refractive correction, particularly for patients with high astigmatism, and is worn on the ocular surface using the siphonic principle without directly abrading the cornea, with less damage to the cornea, and that can be worn for extended periods of time. In recent years, rigid corneal contact lenses have rapidly become widespread worldwide due to the synthesis and application of high-molecular materials with high Dk values, high elastic modulus, hydrophilicity, precipitation resistance, and good biocompatibility.

In clinical medicine of ophthalmology, light rays passing through an eyeball and focusing in front of a retina can be called myopic defocusing; if the focus is behind the retina, it may be called hyperopic defocus. Clinical studies in recent years have shown that if the retinal periphery is imaged as myopic defocus, it is possible to slow down the growth of the eye axis, thereby preventing and controlling further progression of myopia. Based on the clinical studies, it is possible to retard the further progression of myopia in teenagers whose degree of myopia is still in the development stage if myopic defocus is formed around the retina while the teenagers wear prescription lenses to correct their vision.

However, the existing RGPs can only be used for refractive correction, and in order to make the RGPs used for refractive correction and simultaneously for slowing down myopia progression, a multifocal design of the RGPs is required, that is, in order to realize different functions, the lens is divided into a plurality of different functional regions, and each functional region is designed to have different arcs, for example, different curvature radii, etc. However, in the RGP, since the functional regions have different arcs, sharp points may be formed at the junctions of the regions, which may result in poor wearing comfort.

Disclosure of Invention

In view of the above-described conventional circumstances, an object of the present invention is to provide a myopia-preventing/controlling type contact lens which is comfortable to wear.

To this end, the present invention provides a myopia prevention and control type contact lens having an inner surface facing a cornea when worn and matching an anterior surface of the cornea, and an outer surface opposing the inner surface, the myopia prevention and control type contact lens having a prescription zone having a first refractive power based on correcting refractive error of an eye and an non-prescription zone having a second refractive power different from the first refractive power, on an XZ plane constituted with a rise direction of the myopia prevention and control type contact lens being a Z-axis direction, a width direction of the myopia prevention and control type contact lens being an X-axis direction, and an apex of the outer surface being an origin, X representing a distance from the Z-axis of a point on the inner surface, the outer surface, or the anterior surface of the cornea, a junction between the prescription zone and the non-prescription zone being formed as a smooth curve, and the outer surface satisfies:

wherein x is_iAt least any point selected from a connection point between the prescription zone and the non-prescription zone, a boundary point of the outer surface, Z (x)_i) To express said appearanceFace x ═ x_iRise of point, R_a(x_i) Denotes that the outer surface is x ═ x_iAnd the radius of curvature of (b) satisfies:

wherein R is_p(x_i) Denotes that the inner surface is x ═ x_iN represents the refractive index of the myopia prevention and control type corneal contact lens, T_CThe central thickness of the myopia prevention and control type corneal contact lens is shown, and D represents the diopter of the myopia prevention and control type corneal contact lens. In the utility model, the wearing comfort of the myopia prevention and control type corneal contact lens can be improved by designing the outer surface of the myopia prevention and control type corneal contact lens as a continuous and smooth surface; in addition, the myopia prevention and control type corneal contact lens is provided with a prescription area and a non-prescription area, and the prescription area and the non-prescription area can have different diopters by performing defocus design on the outer surface of the myopia prevention and control type corneal contact lens, so that the myopia prevention and control type corneal contact lens can be used for refractive correction and has the effect of controlling or slowing down myopia deepening.

In addition, in the myopia prevention and control type contact lens related to the utility model, optionally, the second refractive power is larger than the first refractive power.

In addition, in the myopia prevention and control type contact lens related to the utility model, optionally, the prescription zone comprises a central prescription zone passing through the center of the lens and at least one peripheral prescription zone surrounding the central prescription zone, the non-prescription zone is positioned at the periphery of the central prescription zone and comprises at least one annular defocus zone, and the annular defocus zone and the peripheral prescription zone are alternately arranged. In this case, the alternating design of the prescription zone and the non-prescription zone can be beneficial to controlling or slowing down the myopia progression, and can meet the vision correction requirement.

In addition, in the myopia prevention and control type corneal contact lens related to the utility model, optionally, the diameter of the central prescription region is 2mm to 6 mm.

In addition, in the myopia prevention and control type cornea contact lens related to the utility model, optionally, the refractive power of the annular focusing area is gradually increased from the center to the outside. Therefore, the myopia prevention and control type corneal contact lens can reduce the myopia progression speed.

In addition, in the myopia prevention and control type contact lens related to the utility model, optionally, the thickness of the central prescription region gradually increases from the center to the outside. Therefore, smooth inner and outer surfaces can be conveniently formed, and the wearing comfort of the corneal contact lens is improved.

In addition, in the myopia prevention and control type contact lens according to the present invention, the difference between the first refractive power and the second refractive power is optionally 0.25D to 15D. In this case, the image of the light passing through the prescription area and the non-prescription area formed on the retina and/or the vicinity of the retina does not generate too large difference when the myopia is worn, and the comfort level when the myopia is worn is improved while the myopia progression is controlled or slowed.

In addition, in the myopia prevention and control type corneal contact lens related to the utility model, optionally, the T_CSelected from any value between 0.10mm and 1.00 mm. Therefore, the deformation of the contact lens 1 can be relieved, and the weight of the contact lens can be reduced.

In addition, in the myopia prevention and control type contact lens related to the present invention, optionally, the area ratio of the prescription region to the non-prescription region is 1: 0.25 to 1: 1.5. in this case, the rate of myopia progression can be reduced by myopia prevention and control type contact lenses.

In addition, in the myopia prevention and control type contact lens related to the utility model, optionally, when the myopia prevention and control type contact lens is worn, the light rays entering the human eye through the prescription zone are focused on the retina, and the light rays entering the human eye through the non-prescription zone are focused in front of the retina. Therefore, the myopia prevention and control type corneal contact lens has the myopia defocusing effect, so that the deepening of myopia can be controlled or slowed down, and meanwhile, the demand of vision correction can be met.

The utility model can provide the myopia prevention and control type corneal contact lens with high wearing comfort.

Drawings

Fig. 1 is a schematic view showing the structure of a contact lens according to an example of the present invention.

Fig. 2 is a view showing an application scenario of a contact lens according to an example of the present invention.

Figure 3 is a design schematic showing the outer surface of a corneal contact lens according to an example of the utility model.

Figure 4 is a zone profile diagram illustrating a contact lens according to an example of the utility model.

Figure 5 is a cross-sectional view showing the outer surface of a corneal contact lens according to an example of the present invention.

Figure 6 is a top view showing a contact lens according to an example of the present invention.

Figure 7 is a cross-sectional view showing the inner surface of a contact lens according to an example of the present invention.

Figure 8 is a bottom view showing a contact lens according to an example of the present invention.

1 … corneal contact lens, 2 … cornea,

10 … outer surface, 11 … optical surface, 12 … peripheral surface,

20 … inner surface, 21 … base curve, 22 … side curve,

1a … central prescription zone, 1b … peripheral prescription zone,

1c … annular defocus region, 1d … edge warp region.

Detailed Description

All references cited herein are incorporated by reference in their entirety as if fully set forth. Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same components are denoted by the same reference numerals, and redundant description thereof is omitted. The drawings are schematic and the ratio of the dimensions of the components and the shapes of the components may be different from the actual ones.

The utility model relates to a myopia prevention and control type corneal contact lens, which is a corneal contact lens used for refractive correction and myopia control. The myopia prevention and control type corneal contact lens can be called as a corneal contact lens for short, and can also be called as an RGP, a multifocal RPG, a contact lens and the like. The corneal contact lens can meet the requirement of vision correction and control or slow down the deepening of myopia.

Fig. 1 is a schematic view showing the structure of a contact lens 1 according to an example of the present invention. Fig. 2 is a view showing an application scenario of the contact lens 1 according to the example of the present invention.

In some examples, the contact lens 1 may have an inner surface 20 that faces the cornea 2 when worn, and an outer surface 10 opposite the inner surface 20 (see fig. 1 and 2).

In some examples, the contact lens 1 may have a prescription zone and an over-the-counter zone (described later). The prescription zone may have a first refractive power based on correcting refractive error of the eye. The over-the-counter zone may have a second refractive power different from the first refractive power.

In some examples, when the contact lens 1 is worn, light entering the human eye via the prescription zone is focused on the retina, and light entering the human eye via the non-prescription zone is focused in front of the retina. In this case, by setting the prescription zone and the non-prescription zone to have different diopters, the contact lens 1 can be made to have a myopic defocus effect, so that the progression of myopia can be controlled or slowed, and at the same time, the demand for vision correction can be satisfied.

Fig. 3 is a schematic design diagram showing the outer surface 10 of a corneal contact lens 1 according to an example of the utility model. The design of the outer surface 10 of the contact lens 1 according to an example of the present invention will be described in detail below with reference to fig. 3.

As shown in fig. 3, on an XZ plane constituted with the sagittal direction of the contact lens 1 as the Z-axis direction, the widthwise direction of the contact lens 1 as the X-axis direction, and the apex of the outer surface 10 as the origin, X represents the distance of a point on the inner surface 20, the outer surface 10, or the front surface of the cornea 2 from the Z-axis, the junction between the prescription zone and the non-prescription zone is formed as a smooth curve, and the outer surface 10 satisfies:

wherein x is_iAt least any point selected from the group consisting of a connection point between the prescription area and the non-prescription area, and a boundary point of the outer surface 10, Z (x)_i) Denotes that the outer surface 10 is x ═ x_iRise of (c), R_a(x_i) Means that the outer surface 10 is x ═ x_iAnd the radius of curvature of (b) satisfies:

wherein R is_p(x_i) Meaning that the inner surface 20 is x ═ x_iN represents the refractive index of the corneal contact lens 1, T_CThe central thickness of the contact lens 1 is shown, and D shows the diopter of the contact lens 1. In this case, the outer surface 10 of the contact lens 1 can be designed as a continuous and smooth surface, so that the wearing comfort of the contact lens 1 can be improved.

In some examples, the radius of curvature R of the inner surface 20_p(x_i) Can be obtained based on corneal topography.

In some examples, diopter D may be obtained from the result of the examination of the human eye. In particular, diopter D may be obtained based on the vision requiring correction. For example, diopter D may be taken from either the first refractive power or the second refractive power.

In some examples, T_CMay be selected from any value between 0.10mm and 1.00 mm. E.g. T_CCan be 0.10mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1.00 mm. Therefore, the deformation of the contact lens 1 can be relieved, and the weight of the contact lens 1 can be reduced.

Fig. 4 is a sectional view showing a contact lens 1 according to an example of the present invention.

In some examples, the prescription zone may include a central prescription zone 1a passing through the center of the lens, and at least one peripheral prescription zone 1b surrounding the central prescription zone 1 a. For example, in the example shown in fig. 4, the prescription zone may include a central prescription zone 1a passing through the center of the lens, and a peripheral prescription zone 1b surrounding the central prescription zone 1 a.

In some examples, the thickness of the central prescription area 1a may gradually increase from the center outward. Thereby, it is possible to facilitate the formation of smooth inner and outer surfaces, thereby improving the wearing comfort of the contact lens 1.

In some examples, the central prescription zone 1a and the peripheral prescription zone 1b may differ in diopter. Thereby, it is possible to adapt to different diopter requirements.

In some examples, the central prescription zone 1a may be 2mm to 6mm in diameter. For example, the central prescription zone 1a may have a diameter of 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, or 6 mm. In other examples, the diameter of central prescription area 1a may also be selected based on the size of the pupil.

In some examples, the non-prescription region may be disposed around the periphery of the prescription region. In some examples, the non-prescription regions may be located at the periphery of the central prescription region 1a and include at least one annular defocus region 1c, and the annular defocus regions 1c may be arranged alternately with the peripheral prescription regions 1b (see fig. 4). That is, in the case where the prescription regions include only the central prescription region 1a and one peripheral prescription region 1b, the annular defocus region 1c may be located between the central prescription region 1a and the peripheral prescription region 1 b; in the case where the prescription regions include a central prescription region 1a and a plurality of peripheral prescription regions 1b, the number of annular defocus regions 1c may be plural and located between the central prescription region 1a and the peripheral prescription region 1b and between the peripheral prescription region 1b and the peripheral prescription region 1b, respectively. In this case, the alternating design of the prescription zone and the non-prescription zone can be beneficial to controlling or slowing down the myopia progression, and can meet the vision correction requirement.

In some examples, as shown in fig. 4, the contact lens 1 may further include an edge warp zone 1 d. In other examples, the warped region 1d may be the outermost periphery of the lens. In some examples, the thickness of the edge warp region 1d may gradually decrease as going away from the edge region 1 c. This can contribute to tear exchange.

In some examples, as described above, x_iAt least selected from the connection points between the prescription and non-prescription areas. In the embodiment shown in FIG. 3, P₁Is the boundary point P between the central prescription region 1a and the annular defocus region 1c₂Is the boundary point P between the annular defocus area 1c and the peripheral prescription area 1b₃Boundary point P between peripheral prescription region 1b and edge warping region 1d₄Being the boundary point of the outer surface 10. x is the number of_iCan be selected from P₁、P₂、P₃And P₄The value of x corresponding to any point in (a).

In some examples, the second optical power may be greater than the first optical power. In this case, when wearing the myopia prevention and control type contact lens, light entering the human eye through the prescription zone may be focused on the retina, and light entering the human eye through the non-prescription zone may be focused in front of the retina.

In some examples, the difference between the first optical power and the second optical power may be 0.25D to 15D. In this case, the image of the light passing through the prescription area and the non-prescription area formed on the retina and/or the vicinity of the retina does not generate too large difference when the myopia is worn, and the comfort level when the myopia is worn is improved while the myopia progression is controlled or slowed.

In some examples, the contact lens 1 may have a progressive optical power.

In some examples, the power of the annular defocus area 1c may gradually increase from the center outward. In this case, on the one hand, the speed of myopia progression can be reduced, and on the other hand, there can be a facility to form a smooth outer surface 10 and/or inner surface 20 to improve wearing comfort.

In some examples, the ratio of the area of the prescription region to the non-prescription region is 1: 0.25 to 1: 1.5. in this case, it is possible to adapt to the requirements of different human eyes.

In other examples, the non-prescription area may be a plurality of small areas (not shown) dispersedly disposed within the prescription area.

In some examples, the prescription and non-prescription zones may be cooperatively formed by the front surface 10 and the back surface 20 (described in detail later).

In some examples, as shown in fig. 2, when the contact lens 1 is worn on the eyeball, a tear space may be formed between the inner surface 20 and the cornea 2. This reduces wear of the cornea 2 by the contact lens 1, and improves wearing comfort.

In some examples, the tear space may be filled with tears. In other examples, the tear space may be filled with a therapeutic solution. Additionally, in some examples, the tear layer within the tear space may be formed as a tear mirror. This can contribute to astigmatism correction.

In some examples, the contact lens 1 may be fitted based on the corneal 2 curvature and the corneal 2 astigmatism values of the cornea 2. Therefore, the corneal contact lens 1 can be matched with the cornea 2, and the wearing comfort and the definition of vision correction can be improved. For example, the curvature of the base curve surface 21 of the inner surface 20 may be greater than the curvature of the cornea 2.

In some examples, the corneal contact lens 1 may be constructed of a rigid material. In other examples, the corneal contact lens 1 may be constructed of a rigid, highly oxygen permeable material. In this case, it is possible to make the contact lens 1 have good oxygen permeability, to improve the abrasion resistance of the contact lens 1, and to facilitate the production of the contact lens 1.

In some examples, the oxygen permeability coefficient (DK value) of the hard high oxygen permeable material may be from 100 to 200. Thereby, the utility model has better oxygen permeability, so that tear can provide oxygen for the cornea 2, thereby being beneficial to keeping the cornea 2 healthy. For example, the DK value of a rigid high oxygen permeable material may be 100, 125 or 141.

In some examples, the rigid high oxygen permeable material may be one selected from the group consisting of silicone methacrylate, fluorosilicone methacrylate, perfluoroether, fluorinated silicone.

In some examples, the corneal contact lens 1 may have a diameter of 8.5mm to 12.0 mm. For example, the corneal contact lens 1 may have a diameter of 8.5mm, 8.8mm, 9mm, 9.2mm, 9.6mm, 10.0mm, 10.2mm, 10.5mm, 10.8mm, 11mm, 11.2mm, 11.5mm, 11.8mm, or 12 mm.

Further, in some examples, the corneal contact lens 1 may be 0.10mm to 1.00mm thick. Therefore, the deformation of the contact lens 1 can be relieved, and the weight of the contact lens 1 can be reduced. For example, the corneal contact lens 1 may have a thickness of 0.10mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1 mm.

In some examples, the contact lens 1 may be a hybrid contact lens that is a combination of both hard and soft lenses. In addition, in some examples, the central region of the contact lens 1 may be composed of a hard material and the peripheral region may be composed of a soft material.

Figure 5 is a cross-sectional view showing the outer surface 10 of a contact lens 1 according to an example of the utility model. Fig. 6 is a plan view showing a contact lens 1 according to an example of the present invention.

In some examples, as described above, the outer surface 10 may be of an out-of-focus design. In this case, by performing defocus design on the outer surface 10, the prescription zone and the non-prescription zone can have different diopters, and the contact lens 1 can have a myopic defocus effect, so that the progression of myopia can be controlled or slowed, and at the same time, the demand for vision correction can be satisfied.

In some examples, the outer surface 10 may include an optical surface 11 and a perimeter surface 12 (see fig. 5). The optical surface 11 may correspond to the prescription zone. In the example shown in fig. 6, the optical surface 11 may be located in the center of the outer surface 10, with the peripheral surface 12 formed around the optical surface 11.

In some examples, the curvature of the optical surface 11 may be less than the curvature of the peripheral surface 12. Thereby, it can be facilitated to form the outer surface having the first predetermined shape. For example, the outer surface 10 may be formed in a first predetermined shape as shown in fig. 5.

In some examples, the diameter D of the optical surface 11₁And may be 7mm to 10 mm. For example, the diameter D of the optical surface 11₁May be 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm or 10 mm. As shown in FIG. 5, the diameter D of the optical surface 11₁May refer to the maximum linear distance between two points corresponding to the edges of the optical surface 11.

In some examples, the contact lens 1 may be formed as a multifocal contact lens via an anterior surface defocus design. In this case, the defocusing design on the outer surface 10 of the contact lens 1 can cause the contact lens 1 to have different diopters in different areas. Reference may be made to the above regarding the design of the outer surface 10, which will not be described in detail here.

Figure 7 is a cross-sectional view showing the inner surface 20 of a contact lens 1 according to an example of the utility model. Fig. 8 is a bottom view showing a contact lens 1 according to an example of the present invention. In some examples, the inner surface 20 may include a base arc surface 21 and a side arc surface 22 formed around the base arc surface 21 (see fig. 7 and 8). The base curve surface 21 may contact the cornea 2 during wearing, and the side curve surfaces 22 may be connected to the peripheral surface 12 and the base curve surface 21, respectively.

In some examples, the center of base curve surface 21 may correspond to the center of optical surface 11.

In some examples, the curvature of base curve surface 21 may be less than the curvature of peripheral surface 12. Thereby, the formation of the second predetermined shape of the inner surface 20 can be facilitated. For example, the inner surface 20 may be formed in a second predetermined shape as shown in FIG. 7. In some examples, the curvature of the base curve surface 21 may be greater than the curvature of the anterior surface of the cornea 2.

In some examples, the curvature of optical surface 11 may be less than the curvature of peripheral surface 12 and the curvature of base curve surface 21 is less than the curvature of peripheral surface 12. In this case, it is possible to facilitate the formation of the first predetermined shaped outer surface 10 and the second predetermined shaped inner surface 20. Furthermore, the curvature of the base curve surface 21 may be greater than the curvature of the anterior surface of the cornea 2. In this case, it can be advantageous to form a tear space between the inner surface 20 and the cornea 2.

In some examples, as shown in FIG. 1, the edgewise surface 22 may have no curvature. In other words, on a cross section of the contact lens 1 along the rise passing through the center of the contact lens 1, the side arc surface 22 may be formed linearly.

In some examples, the curvature of base curve surface 21 may be equal to the curvature of optical surface 11. In other examples, the curvature of base curve surface 21 may be slightly less than the curvature of optical surface 11. This enables the contact lens 1 to have a gradual refractive power.

In some examples, as shown in FIG. 1, diameter D of base curve 21₂May be larger than the diameter D of the optical surface 11₁. This can contribute to the defocus design of the front surface of the corneal contact lens 1. Additionally, in some examples, diameter D of base curve face 21₂May be 7.7mm to 10.0 mm. For example, the diameter D of the base curve surface 21₂May be 7.7mm, 8mm, 8.3mm, 8.5mm, 8.7mm, 9mm, 9.3mm, 9.5mm, 9.7mm or 10 mm. In the present invention, as shown in FIG. 4, the diameter D of the base curve surface 21₂May refer to the maximum straight-line distance between two points corresponding to the edges of the base arc surface 21.

In some examples, as shown in fig. 1, the side arc surface 22 may be connected with the peripheral surface 12 and the base arc surface 21, respectively. Thereby, the inner surface 20 and the outer surface 10 can be connected to form the corneal contact lens 1.

In some examples, the inner surface 20 may match the shape of the cornea 2, thereby improving comfort when worn.

In some examples, the inner surface 20 may have quadrant specificity, and the inner surface 20 may be designed to match the morphology of different quadrants of the cornea 2 via quadrant division, so that the inner surface 20 can better match the morphology of the cornea 2 of each quadrant, that is, can better contact and fit with the cornea 2 of each quadrant, and thus can help to uniformly disperse the pressure applied to the cornea 2 by the contact lens 1, and thus can improve the safety and comfort of the contact lens 1.

In some examples, the base curve surface 21 may contact the cornea 2 when the contact lens 1 is worn on the eyeball. This enables the corneal contact lens 1 to be fixed to the eyeball. In other examples, the base curve surface 21 may present a contact portion with the cornea 2. In addition, the base curve surface 21 can improve the matching of the contact part and the cornea 2 through quadrant division design, thereby improving the comfort of the corneal contact lens 1.

In some examples, the base curve surface 21 may be spaced from the cornea 2, i.e., the base curve surface 21 may form a tear space with the cornea 2. In addition, in some examples, the thickness of the gap between the base curve surface 21 and the cornea 2 does not exceed 20 μm. This can reduce both loss to the cornea 2 and visual disturbance. For example, the thickness of the gap between the basal arc surface 21 and the cornea 2 may be 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, or 20 μm. In some examples, the prescription zone and the non-prescription zone may be formed by matching optical surface 11 with base curve surface 21. For example, in the example shown in fig. 4, the central prescription region 1a, the peripheral prescription region 1b, and the annular defocus region 1c may be formed by matching the optical surface 11 with the base curve surface 21. The central region of the optical surface 11 may match the central region of the base curve surface 21 to form the central prescription region 1 a. In addition, in some examples, the peripheral prescription region 1b, and the annular defocus region 1c may be formed by matching portions other than the central region of the optical surface 11 with the base curved surface 21. In some examples, as shown in fig. 4, the edge warp zone 1d may be formed by the mating of the perimeter face 12 and the edge arc face 22.

According to the utility model, the corneal contact lens 1 which can be used for refractive correction, can control or slow down myopia progression, and has good wearing comfort can be provided.

While the utility model has been described in detail in connection with the drawings and the embodiments, it is to be understood that the above description is not intended to limit the utility model in any way. Those skilled in the art can make modifications and variations to the present invention as needed without departing from the true spirit and scope of the utility model, and such modifications and variations are within the scope of the utility model.

Claims

1. A myopia prevention and control corneal contact lens having an inner surface that faces the cornea during wear and mates with the anterior surface of the cornea, and an outer surface opposite the inner surface, wherein:

the myopia prevention and control type contact lens has a prescription zone having a first refractive power based on correcting refractive error of an eye and an over-the-counter zone having a second refractive power different from the first refractive power,

on an XZ plane constituted with a sagittal direction of the myopia prevention and control type contact lens as a Z axis direction, a width direction of the myopia prevention and control type contact lens as an X axis direction, and an origin point of a vertex of the outer surface, X represents a distance from the Z axis of a point on the inner surface, the outer surface, or an anterior surface of a cornea, a junction between the prescription zone and the non-prescription zone is formed as a smooth curve, and the outer surface satisfies:

wherein x is_iAt least any point selected from a connection point between the prescription zone and the non-prescription zone, a boundary point of the outer surface, Z (x)_i) Denotes that the outer surface is x ═ x_iRise of point, R_a(x_i) Denotes that the outer surface is x ═ x_iAnd the radius of curvature of (b) satisfies:

wherein R is_p(x_i) Denotes that the inner surface is x ═ x_iN represents the refractive index of the myopia prevention and control type corneal contact lens, T_CThe central thickness of the myopia prevention and control type corneal contact lens is shown, and D represents the diopter of the myopia prevention and control type corneal contact lens.

2. The myopia prevention and control corneal contact lens of claim 1, wherein:

the second optical power is greater than the first optical power.

3. The myopia prevention and control corneal contact lens of claim 1, wherein:

the prescription zone comprising a central prescription zone passing through the center of the lens and at least one peripheral prescription zone surrounding the central prescription zone,

the non-prescription zone is located at the periphery of the central prescription zone and includes at least one annular defocus zone, the annular defocus zone and the peripheral prescription zone being arranged alternately.

4. The myopia prevention and control corneal contact lens of claim 3, wherein:

the central prescription zone has a diameter of 2mm to 6 mm.

5. The myopia prevention and control corneal contact lens of claim 3, wherein:

the power of the annular focusing area is gradually increased from the center to the outside.

6. The myopia prevention and control corneal contact lens of claim 3, wherein:

the thickness of the central prescription region gradually increases from the center to the outside.

7. The myopia prevention and control corneal contact lens of claim 1, wherein:

the difference between the first refractive power and the second refractive power is 0.25D to 15D.

8. The myopia prevention and control corneal contact lens of claim 1, wherein:

the T is_CSelected from any value between 0.10mm and 1.00 mm.

9. The myopia prevention and control corneal contact lens of claim 1, wherein:

the area ratio of the prescription area to the non-prescription area is 1: 0.25 to 1: 1.5.

10. the myopia prevention and control corneal contact lens of claim 1, wherein:

when the myopia prevention and control type contact lens is worn, the light rays entering the human eye through the prescription zone are focused on the retina, and the light rays entering the human eye through the non-prescription zone are focused in front of the retina.