Orthokeratology lens

Abstract

The utility model relates to an orthokeratology lens. The orthokeratology lens has a posterior surface for shaping the anterior surface of the cornea, the posterior surface having a base arc region and a reverse arc region. The curvature radius of the base arc area is gradually reduced from the center to the periphery; and / or the curvature radius of the reverse arc area is smaller than that of the base arc area and is gradually reduced from inside to outside. And / or the area with the preset width at the tail end of the base arc area is set as a transition arc area, and the curvature radius of the transition arc area is smaller than that of the base arc area and larger than that of the reverse arc area. Thus, the rear surface optical region can be lifted to increase the thickness of the central tear layer, so that the region is full of tear.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of orthokeratology lenses. BACKGROUND

[0002] Orthokeratology lenses are worn at night, using mechanical compression, massage of lens movement and the hydraulic pressure of tear fluid, to flatten the curvature of the central cornea. This can temporarily reduce the degree of myopia, improve unaided visual acuity, and provide better visual effects during the day without wearing glasses. At the same time, orthokeratology lenses form a defocus ring in the para-central area of the cornea. This defocus state can make the myopia degree grow more slowly, thereby playing a role in controlling the development of myopia.

[0003] Safety is a key aspect of orthokeratology lenses. The base curve area (i.e., the optical zone) of an orthokeratology lens is used to provide a shaping template for the cornea. By applying positive pressure in the center and negative pressure around the periphery, the orthokeratology lens shapes the cornea. In order to improve the shaping efficiency, the storage space for the tear fluid under the lens may be additionally compressed. Such efficiency improvement is actually not conducive to the health of the cornea. For example, when worn at night, the lens will adhere to the cornea and be difficult to move. It is also difficult to remove the lens in the morning. This can cause the cornea to become stained, the corneal epithelium to fall off, and even more serious adverse events.

[0004] Therefore, there is a need to improve the design of orthokeratology lenses to effectively improve the safety of lens wearing. SUMMARY

[0005] One technical problem to be solved by the utility model is how to design an orthokeratology lens that can improve the safety of lens wearing.

[0006] The utility model provides an orthokeratology lens, which has a back surface for shaping the front surface of the cornea. The back surface has a base curve area and a reverse curve area. The radius of curvature of the base curve area gradually decreases from the center to the periphery. Additionally or alternatively, the radius of curvature of the reverse curve area is smaller than that of the base curve area and gradually decreases from the inside to the outside. Additionally or alternatively, a region with a predetermined width at the end of the base curve area is set as a transition curve area. The radius of curvature of the transition curve area is smaller than that of the base curve area and larger than that of the reverse curve area.

[0007] Optionally, the aspherical characteristic parameter value of the base curve area is configured to increase the sag of the base curve area by a first value.

[0008] Optionally, the eccentricity of the base curve area is in the range of -0.45 to -1.25.

[0009] Optionally, the aspherical characteristic parameter value of the reverse curve area is configured to increase the thickness of the tear fluid layer by a first value.

[0010] Optionally, the eccentricity of the reverse curve area is in the range of -0.20 to -0.60.

[0011] Optionally, the width and the radius of curvature of the transition arc region are configured to increase the tear layer thickness by a first value.

[0012] Optionally, the width of the transition arc region is between 0.1mm and 0.3mm, and the difference between the radius of curvature of the base arc region and the radius of curvature of the transition arc region is between 0.35mm and 3.00mm.

[0013] Optionally, the first value is between 7pm and 10pm.

[0014] Optionally, the back surface further comprises a fitting arc region and a peripheral arc region, the fitting arc region comprises a first fitting arc region and a second fitting arc region, the first fitting arc region is adjacent to the reverse arc region, the second fitting arc region is adjacent to the peripheral arc region, the first fitting arc region is parallel to the corresponding area of the cornea, and the second fitting arc region gradually moves away from the cornea from inside to outside.

[0015] Optionally, the distance between the end of the second fitting arc region and the cornea is between 5pm and 40pm.

[0016] Optionally, the radius of curvature of the second fitting arc region is greater than the radius of curvature of the first fitting arc region by 0.05mm to 1.15mm; and / or the eccentricity of the second fitting arc region is in the range of +0.20 to +0.90.

[0017] The radius of curvature of the base arc region is designed to gradually decrease from the center to the periphery; and / or the radius of curvature of the reverse arc region is designed to be smaller than the radius of curvature of the base arc region and gradually decrease from inside to outside; and / or the region with a predetermined width at the end of the base arc region is set as a transition arc region, the radius of curvature of the transition arc region is smaller than the radius of curvature of the base arc region and greater than the radius of curvature of the reverse arc region. In this way, the back surface optical area can be lifted, the central tear layer thickness can be increased, and the area can be filled with tears. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which like reference characters refer to the like parts throughout the figures, and in which:

[0019] Figure 1 A cross-sectional simplified diagram of a conventional orthokeratology lens is shown.

[0020] Figure 2 A cross-sectional simplified diagram of an orthokeratology lens according to one embodiment of the present application is shown.

[0021] Figure 3 A cross-sectional simplified diagram of an orthokeratology lens according to another embodiment of the present application is shown.

[0022] Figure 4 A simplified cross-sectional view of an orthokeratology lens according to another embodiment of the present invention is shown.

[0023] Figure 5 A simplified cross-sectional view of an orthokeratology lens according to another embodiment of the present invention is shown.

[0024] Figure 6 A simplified cross-sectional view of an orthokeratology lens according to another embodiment of the present invention is shown.

[0025] Figure 7 The accompanying fluorescence staining comparison diagram shows the matching of the orthokeratology lens of this invention with that of a conventional orthokeratology lens. Detailed Implementation

[0026] Preferred embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.

[0027] Figures 1 to 6 Only the posterior surface of the orthokeratology lens, used for reshaping the anterior surface of the cornea, is shown. Because this invention does not concern itself with the design of the anterior surface of the orthokeratology lens, it is omitted in the figures to avoid distraction. Those skilled in the art will understand that this invention is suitable for any appropriate anterior surface design. For example, this invention is suitable not only for orthokeratology lenses worn at night but also for orthokeratology lenses worn during the day.

[0028] Furthermore, all the ranges of values ​​described in the text can include two endpoint values.

[0029] Figure 1 A simplified cross-sectional view of a conventional orthokeratology lens is shown.

[0030] like Figure 1 As shown, the posterior surface of an orthokeratology lens has four zones: the base curve (BC), followed by the reverse curve (RC), alignment curve (AC), and peripheral curve (PC). The base curve is located at the center of the lens. The base curve can also be called the posterior surface optical zone. The reverse curve is adjacent to the base curve. The peripheral curve is adjacent to the alignment curve and is located at the outermost periphery of the lens.

[0031] The back surface of the orthokeratology lens can be generally divided into a central region and a peripheral region. The base curve region and the reverse curve region can be classified into the central region. The fitting curve region and the peripheral curve region can be classified into the peripheral region.

[0032] The utility model provides can slightly lift (namely lift) the optical area (namely base curve region) by optimizing the design to the central region (base curve region and / or reverse curve region), to increase the central tear layer thickness, to make the region tear liquid full.

[0033] The utility model also provides can form the soft, no obvious transition edge warping by optimizing the design to the peripheral region (for example fitting curve region), to make the lens under tear liquid full, and tear liquid exchange soft and smooth.

[0034] In some preferred embodiments, the above two optimization designs can be used simultaneously to effectively improve the safety of lens wearing without damaging the molding efficiency.

[0035] I. Optimization design for the central region

[0036] The purpose of optimizing the central region is to slightly lift the back surface optical area to increase the central tear layer thickness.

[0037] When fitting the orthokeratology lens, the optometrist or fitter can increase the overcorrection based on the wearer's expectation of molding effect and molding efficiency, that is, reduce the base curve by 0.25-1.00D, that is, increase the base curve radius by 0.04-0.30mm, for example, the classic spherical four-arc VST design orthokeratology lens, which will result in a decrease of 4-18 μm in the molding area tear layer, and if the tear layer at the center vertex of the cornea is originally 10 μm, such parameter adjustment will cause the lens center vertex to contact and overpressure, causing corneal health problems.

[0038] Therefore, it is necessary to optimize the tear layer. The main purpose of optimizing the tear layer is: on the one hand, to ensure the shape of the tear layer, so that the tear layer forms an effective negative pressure, ensuring the molding efficiency; on the other hand, to ensure the thickness of the tear layer everywhere, so that the tear liquid under the lens is always full and lubricated, ensuring the safety and health of the cornea.

[0039] The utility model provides three ways to lift the back surface optical area (i.e. increase the central tear layer thickness). The three ways can be used alone or in combination. For example, any two or three ways can be used in combination.

[0040] Method 1: Design the base curve region as aspheric with negative e value

[0041] The base curve region can be designed as an aspheric surface, and the aspheric surface has a characteristic parameter value such that the radius of curvature of the base curve region gradually decreases from the center to the periphery. The aspheric surface characteristic parameter value can be referred to as an e value. The e value represents eccentricity. A positive or negative e value indicates whether an oblate curve or an elongated curve is used. A positive e value indicates that an elongated curve is used, and the radius of curvature gradually increases from the inside to the outside. A negative e value indicates that an oblate curve is used, and the radius of curvature gradually decreases from the inside to the outside.

[0042] The purpose of designing the base curve region as an aspheric surface with a negative e value is to gradually decrease the radius of curvature of the base curve region from the center to the periphery. In this way, the peripheral defocus area and the defocus amount are improved without affecting the patient's visual effect. At the same time, compared with a spherical surface design (or an aspheric surface design with a positive e value) for the base curve region, the optical zone sag (i.e., the base curve region sag) of the lens is higher, which is equivalent to the optical zone being slightly raised (i.e., the lens center being arched), so that the tear layer between the lens and the cornea can be increased in thickness, for example, by about 5 μm to 15 μm. In this way, for the lens after wearing the orthokeratology lens, it is helpful to promote the exchange of the lens to maintain the integrity of the cornea and reduce the corneal damage caused by the orthokeratology lens.

[0043] Figure 2 A cross-sectional simplified diagram of an orthokeratology lens according to an embodiment of the present application is shown.

[0044] Referring to Figure 2 , the dashed line in the lens corresponding to the BC region can represent that the BC region adopts a spherical surface design, and the solid line in the lens corresponding to the BC region represents that the BC region adopts an aspheric surface design and has a negative e value. Compared with a spherical surface design for the base curve region, by designing the base curve region as an aspheric surface with a negative e value, the BC region sag can be increased, and the central tear layer thickness can be improved.

[0045] The aspheric surface characteristic parameter value (e value) and the aspheric surface sag have a certain functional relationship, which can be represented by an aspheric surface-sag function. Therefore, for the desired BC region sag, the aspheric surface characteristic parameter value required for the BC region to have the sag can be calculated using the aspheric surface-sag function.

[0046] That is, the aspheric surface characteristic parameter value of the BC region can be determined according to the desired BC region sag. For example, the aspheric surface characteristic parameter value of the base curve region can be configured to increase the base curve region sag (i.e., the aspheric surface sag) by a first value. Increasing the base curve region sag by the first value is equivalent to increasing the tear layer thickness by the first value. For example, the aspheric surface characteristic parameter value of the base curve region can be determined to increase the base curve region sag by 5 μm to 15 μm. Increasing the base curve region sag by the first value can mean increasing the base curve region sag by the first value compared with the base curve region sag corresponding to the original design.

[0047] The sag of asphere can be expressed as:

[0048]

[0049] wherein Sag(r) represents the sag of asphere, c represents the vertex curvature of asphere (1 / radius of vertex curvature), and r represents the semi-chord length of asphere. When the sag of BC zone is calculated by using the formula, z represents the sag of BC zone, c represents the curvature at the center of BC zone, and r represents the diameter / 2 of BC zone. The value of Q is in a square relationship with the value of e in opposite signs. The relationship between the value of Q and the value of e can be expressed by the following formula,

[0050]

[0051] The sag of BC zone is positively correlated with the thickness of central tear layer. According to the sag of BC zone that meets the requirements, the value range of e that meets the expected value can be calculated by using the above formula. For example, in order to lift the back surface optical zone by 5 μm to 15 μm, the value range of e of BC zone calculated is -0.45 to -1.25, for example, -0.45, -0.50, -0.55, -0.60, -0.65, -0.70, -0.75, -0.80, -0.85, -0.90, -0.95, -1.00, -1.05, -1.10, -1.15, -1.25, or any value within the range, or any value within any sub-range within the range of -0.45 to -1.25, for example, a range composed of any two values listed herein as end points.

[0052] For example, when the value of e is -0.45, the back surface optical zone is lifted by 5 μm, which is slightly lifted compared with the old generation of orthokeratology lens design, and the central tear layer thickness of some degrees does not change significantly.

[0053] For example, when the value of e is -1.25, the back surface optical zone is lifted by 15 μm, which is more lifted compared with the old generation of orthokeratology lens design, and the central tear layer thickness of some degrees reaches 35 μm.

[0054] In addition, it is found through research that when the back surface optical zone is lifted by about 7 μm to 10 μm, the lifting amount is appropriate compared with the old generation of orthokeratology lens design, and each degree shows a reasonable lifting value. Therefore, the third numerical value can be 7 μm to 10 μm. That is, the value of e of the base curve zone can be determined by aiming to lift the sag of the base curve zone by 7 μm to 10 μm. That is, one preferred value range of the value of e of the base curve zone is the value range of e corresponding to lifting the sag of the base curve zone by 7 μm to 10 μm.

[0055] Method 2: Designing the reverse curve zone as asphere with a negative value of e

[0056] Figure 3Figure 3 A cross-sectional simplified diagram of a corneal molding lens according to another embodiment of the present application is shown.

[0057] Referring to Figure 3 , the dashed line in the lens corresponding to the RC area indicates that the RC area adopts a spherical design, and the solid line in the lens corresponding to the RC area indicates that the RC area adopts an aspherical design and has a negative e value. The BC area can still adopt a spherical design. Compared with the RC area adopting a spherical design, by designing the RC area as aspherical and having a negative e value, the BC area can also be slightly lifted, thereby increasing the central tear layer thickness. Therefore, the reverse arc area can be designed as aspherical, and the aspherical characteristic parameter value (i.e., the e value) is such that the curvature radius of the reverse arc area is smaller than that of the base arc area, and gradually decreases from inside to outside. In this way, the purpose of lifting the BC area and increasing the central tear layer thickness can also be achieved.

[0058] The aspherical characteristic parameter value of the reverse arc area can be configured to increase the tear layer thickness by a first value. The first value may, for example, refer to the 7 μm to 10 μm mentioned above. Increasing the tear layer thickness by the first value may refer to increasing the tear layer thickness by the first value compared with the tear layer thickness corresponding to the original design.

[0059] For example, the aspherical characteristic parameter value of the reverse arc area can be configured to make the tear layer thickness greater than or equal to a second value. The second value can be flexibly set according to actual conditions. For example, the central tear thickness of a conventional OK lens and cornea itself is about 10 μm, and for example, to increase the tear layer thickness by about 5 μm to 15 μm compared with the conventional thickness, the second value can be set to about 15 μm to 25 μm.

[0060] According to the desired value of the tear layer thickness increased by the RC area by lifting the BC area, the required eccentricity of the RC area can be calculated. For example, the value range of the eccentricity of the RC area is -0.20 to -0.60, such as -0.20, -0.25, -0.30, -0.35, -0.40, -0.45, -0.50, -0.55, -0.60, or any value within the range.

[0061] For example, when the e value is selected as -0.20, the back surface optical area is lifted by 5 μm, which is slightly higher than the old generation of corneal molding lens design, and the central tear layer thickness of some degrees does not change significantly.

[0062] For example, when the e value is selected as -0.60, the back surface optical area is lifted by 15 μm, which is higher than the old generation of corneal molding lens design, and the central tear layer thickness of some degrees reaches 35 μm.

[0063] For example, when the e value is -0.30 to -0.40, the back surface optical zone is lifted by about 7 μm to 10 μm, which is more appropriate compared to the lifting amount of the old generation of orthokeratology lens design, and each power shows a reasonable lifting value.

[0064] Option 3, the end of the base curve zone is set as a transition curve zone

[0065] Figure 4 A cross-sectional simplified diagram of an orthokeratology lens according to another embodiment of the present application is shown.

[0066] Referring to Figure 4 The end of the BC zone with a predetermined width can be set as a transition curve (TC) zone. For example, the end of the BC zone with a width of about 0.1 mm to 0.3 mm can be set as a transition curve zone. That is, the width of the transition curve zone can be between 0.1 mm and 0.3 mm. The radius of curvature of the transition curve zone is smaller than the radius of curvature of the base curve zone and larger than the radius of curvature of the reverse curve zone. By modifying the end of the BC zone with a predetermined width to a TC zone, the BC zone can also be lifted to a certain extent, thereby increasing the central tear layer thickness.

[0067] The width and radius of curvature of the transition curve zone are configured to increase the tear layer thickness by a first value. The first value may, for example, refer to the 7 to 10 μm mentioned above.

[0068] For example, the width and radius of curvature of the transition curve zone can be configured to make the tear layer thickness greater than or equal to a second value. For the second value, please refer to the relevant description above.

[0069] In the manufacture of orthokeratology lenses, the width and radius of curvature of the TC zone can be calculated according to the desired value of the TC zone by which the BC zone is lifted to thicken the tear layer. For example, the width of the transition curve zone is between 0.1 mm and 0.3 mm, and the difference between the radius of curvature of the base curve zone and the radius of curvature of the transition curve zone is between 0.35 mm and 3.00 mm.

[0070] For example, when the width of the TC zone is set to 0.1 mm, the difference between the radius of curvature of the base curve zone (i.e., the base curve zone at the position connected to the transition zone) and the radius of curvature of the transition curve zone can be selected from 0.70 mm to 3.00 mm; when the width of the TC zone is set to 0.2 mm, the difference between the radius of curvature of the base curve zone and the radius of curvature of the transition curve zone can be selected from 0.40 mm to 1.80 mm; and when the width of the TC zone is set to 0.3 mm, the difference between the radius of curvature of the base curve zone and the radius of curvature of the transition curve zone can be selected from 0.35 mm to 1.40 mm.

[0071] According to clinical data, when the central tear layer thickness under the lens is increased by 5-15 μm through the above three ways, the lens under the lens has a full tear layer which can be observed by fluorescence staining, and during the 12-month observation period, the patients have good wearing comfort, and the molding efficiency is not impaired by the increase of the central tear layer thickness under the lens.

[0072] In addition, when the central tear layer under the lens exceeds 35 μm, it will greatly reduce the molding efficiency of the orthokeratology lens, and the molding efficiency impaired by the excessive increase of the central tear layer thickness under the lens cannot be compensated by the above three ways or their combination. Therefore, when increasing the tear layer thickness by the above three ways or their combination, the increase of the tear layer thickness can be limited to the condition that the central tear layer under the lens does not exceed 35 μm.

[0073] In small-scale tests, the above three ways can be used alone or in combination, and it has been verified that the following examples with different parameter combinations have similar, improved fitting characteristics, molding efficiency and comfort:

[0074] a. The e value of the base curve area is -0.45, or -0.55, or -0.70;

[0075] b. The e value of the reverse area is -0.20, or -0.30, or -0.40;

[0076] c. The transition area width is 0.20 mm, and the radius of curvature is the base radius minus 0.40 mm, or 0.60 mm.

[0077] It should be understood that based on the above optimization design of the present application, even if additional overcorrection is given, it will not cause overpressure and will not cause corneal health problems. Therefore, the orthokeratology lens of the present application can refer to an orthokeratology lens with additional overcorrection.

[0078] II. Optimization design for the peripheral area

[0079] The fitting curve area can adopt a double-fitting curve design to form a soft and no obvious transition edge lift with the peripheral curve area.

[0080] The fitting curve area includes a first fitting curve area and a second fitting curve area. The first fitting curve area is a fitting curve close to the lens center, and the first fitting curve area is connected with the reverse curve area. The first fitting curve area is designed to be parallel to the corresponding area of the cornea. The second fitting curve area is a fitting curve close to the lens edge, and the second fitting curve area is connected with the edge curve area. The second fitting curve area is designed to gradually move away from the cornea from inside to outside, so as to form a soft and no obvious transition edge lift with the peripheral curve area.

[0081] The peripheral arc region of the orthokeratology lens is usually of a fixed width, for example, 0.3-0.5 mm wide. The radius of curvature thereof determines the edge lift of the lens, thereby affecting the exchange of the under-lens tear fluid and the movement degree and comfort of the lens. The utility model discloses a second fitting arc region is designed to gradually move away from the cornea from inside to outside, so that the second fitting arc region can be combined with the peripheral arc region into an ultra-wide edge lift, the ultra-wide edge lift is more soft and has no obvious transition, thereby making the under-lens tear fluid full and the exchange of the tear fluid soft and smooth.

[0082] Exemplarily, the distance between the end of the second fitting arc region (the position connected with the peripheral arc region) and the cornea can be between 5 μm and 40 μm. Wherein, the end of the second fitting arc region can form an edge lift with a predetermined distance (such as 5 μm-40 μm) from the cornea by changing the radius of curvature of the second fitting arc region, or the end of the second fitting arc region can form an edge lift with a predetermined distance from the cornea by designing the second fitting arc region as aspheric. Alternatively, the two ways can be used simultaneously to make the end of the second fitting arc region form an edge lift with a predetermined distance from the cornea.

[0083] When the end of the second fitting arc region forms an edge lift with a predetermined distance from the cornea by changing the radius of curvature of AC2 and / or setting AC2 as aspheric, the radius of curvature and / or the eccentricity of AC2 can be calculated according to the value of the predetermined distance.

[0084] According to the clinical data, when the thickness of the tear fluid layer at the end of the second fitting arc region of the orthokeratology lens improved by the above-mentioned manner is lifted by 5 μm-40 μm, it can be observed by fluorescence staining that the second fitting arc region has a thinner under-lens tear fluid layer, and in a 12-month observation period, the patient has good wearing comfort, and the lens fitting is not changed due to the design improvement.

[0085] According to the above design principle, the utility model also makes a clinical test to verify the effectiveness of the above design. The results show that by improving the central tear fluid layer and the peripheral tear fluid layer, the safety of the orthokeratology lens can be effectively improved, and the occurrence of 34% of instrument-related adverse events is reduced, which breaks the old orthokeratology lens cognition about the tear fluid layer.

[0086] In summary, by increasing the thickness of the central region and the peripheral region as described in the foregoing, the safety of the orthokeratology lens can be effectively improved, and the shaping efficiency of the orthokeratology lens is not lost.

[0087] Figure 5 A cross-sectional simplified view of an orthokeratology lens according to another embodiment of the utility model is shown.

[0088] Referring to Figure 5AC1 represents a first fitting arc region, and AC2 represents a second fitting arc region. The radius of curvature of AC2 can be set to be greater than the radius of curvature of AC1, and the radius of curvature of AC2 is greater than the radius of curvature of AC1 by 0.05mm-1.15mm. In this way, the end of the second fitting arc region can be formed with a edge curling of 5um-40um.

[0089] Figure 6 A cross-sectional simplified diagram of a corneal molding lens according to another embodiment of the present application is shown.

[0090] Referring to Figure 6 AC2 can be set to be aspherical, and the eccentricity is in a range of +0.2 to +0.9. In this way, the end of the second fitting arc region can also be formed with a edge curling of 5um-40um.

[0091] The present application belongs to the optimization of details of a lens and even under-lens tear, and can improve the under-lens tear state of a central molding region and a peripheral fitting region, so that the under-lens tear layer is distributed full and exchanged fully and gently, thereby making the safety of the lens wearing better.

[0092] Figure 7 A fitting fluorescent dye comparison diagram of a corneal molding lens of the present application and a conventional corneal molding lens is shown.

[0093] Figure 7 The left side in the middle is a tear fluorescent dye diagram of the corneal molding lens of the present application, Figure 7 The right side in the middle is a tear fluorescent dye diagram of a conventional corneal molding lens. As Figure 7 As shown in the left side view, in the fitting arc region (C region), the first fitting arc region (the part in the red circle) shows a darker color, representing that the under-lens tear layer is less; the second fitting arc region (the part outside the red circle) shows a slightly brighter green color, which indicates that the under-lens tear layer is slightly more.

[0094] Comparison Figure 7 As can be seen from the left side view and the right side view, the under-lens tear after the optimization design has the characteristics of gentle transition, and there is no obvious boundary between the regions. Moreover, the clinical test results show that the corneal molding lens of the present application optimizes the tear distribution and exchange, and significantly reduces the incidence of common adverse reactions, such as corneal point dyeing, conjunctivitis, keratitis, corneal abrasion, and corneal injury, and the incidence of the above is reduced by 26%-63% respectively, which shows that the present application has obvious effect on the safety improvement of the corneal molding lens.

[0095] The corneal molding lens according to the present application has been described in detail above with reference to the drawings.

[0096] The above has described various embodiments of the present application, the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles, practical application, or improvement of technology in the market of the embodiments, or to enable other ordinary skilled in the art to understand the embodiments disclosed herein.

Claims

1. A contact lens having a back surface for reshaping a cornea, the back surface having a base curve zone and an inverse curve zone, characterized in that, a radius of curvature of the base curve zone gradually decreases from the center to the periphery; and / or a radius of curvature of the inverse curve zone is smaller than that of the base curve zone and gradually decreases from the inside to the outside; and / or a region of a predetermined width at the end of the base curve zone is set as a transition curve zone, the radius of curvature of the transition curve zone is smaller than that of the base curve zone and larger than that of the inverse curve zone. 2.The contact lens according to claim 1, characterized in that, a non-spherical characteristic parameter value of the base curve zone is configured to make the base curve zone sag increase by a first value. 3.The contact lens according to claim 2, characterized in that, a value range of the eccentricity of the base curve zone is -0.45 to -1.

25. 4.The contact lens according to claim 1, characterized in that, a non-spherical characteristic parameter value of the inverse curve zone is configured to make the tear layer thickness increase by a first value. 5.The contact lens according to claim 4, characterized in that, a value range of the eccentricity of the inverse curve zone is -0.20 to -0.

60. 6.The contact lens according to claim 1, characterized in that, the width and the radius of curvature of the transition curve zone are configured to make the tear layer thickness increase by a first value. 7.The contact lens according to claim 6, characterized in that, the width of the transition curve zone is between 0.1 mm and 0.3 mm, a difference between the radius of curvature of the base curve zone and the radius of curvature of the transition curve zone is between 0.35 mm and 3.00 mm.

8. The orthokeratology lens of any one of claims 3 to 7, wherein, the first value is between 7 μm and 10 μm.

9. The orthokeratology lens of claim 1, wherein , the back surface further has a fitting curve zone and a peripheral curve zone, the fitting curve zone includes a first fitting curve zone and a second fitting curve zone, the first fitting curve zone is connected to the inverse curve zone, and the second fitting curve zone is connected to the peripheral curve zone, the first fitting curve zone is parallel to the corresponding area of the cornea, and the second fitting curve zone gradually moves away from the cornea from the inside to the outside.

10. The orthokeratology lens of claim 9, wherein , a distance between the end of the second fitting curve zone and the cornea is between 5 μm and 40 μm.

11. The orthokeratology lens of claim 10, wherein , a radius of curvature of the second fitting curve zone is larger than that of the first fitting curve zone by 0.05 mm to 1.15 mm; and / or a value range of the eccentricity of the second fitting curve zone is +0.20 to +0.90.

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