Corneal reshaping lens and its design method

Abstract

The present disclosure describes an orthokeratology lens which has an inner surface facing the cornea when worn. The inner surface is continuously formed with an optical zone, a reverse curve zone and a fitting curve zone from the center outwards. Taking the center position of the inner surface as the base point and the preset contact point of the fitting curve zone on the anterior surface of the eyeball as the landing point, the sagittal height H of the landing point L is: H L = H1 + T c , T c > 0, the sagittal height H of the boundary point of the lens in the optical zone p is: H p = H2 + T c - T p , T p is greater than T c , and the difference ΔT between T p and T c is set based on the target basic parameters. Taking the junction of the reverse curve zone and the fitting curve zone as the reverse edge point, the sagittal height H of the reverse edge point F satisfies: H F = H L - A, where A takes any value between 0 and 0.42 mm. According to the present disclosure, an orthokeratology lens with good adaptability, good shaping effect and high wearing comfort can be provided. In addition, the present disclosure also provides a design method for an orthokeratology lens.

Description

Technical Field

[0001] The present invention generally relates to the field of ophthalmic medical devices, and particularly to a corneal reshaping lens and a design method thereof. Background Art

[0002] A corneal reshaping lens (OK lens) is a rigid corneal contact lens, which is designed with an inverse geometry so that when worn, the epithelial cells of the cornea migrate, and thus the epithelial cells of the cornea are redistributed to change the geometric shape of the anterior surface of the cornea to correct vision.

[0003] Currently, corneal reshaping lenses are generally designed to include an optical zone, a tear zone, and a peripheral zone from the center outwards. When worn, a positive pressure applied to the anterior surface of the cornea is usually generated in the optical zone by, for example, the hydrodynamic force of the tear fluid between the lens and the cornea, so that the epithelial cells of the cornea may migrate to change the refractive power of the cornea.

[0004] However, the existing corneal reshaping lenses do not achieve good adaptation to individual differences, which may lead to problems such as poor shaping effect (poor myopia control effect) and strong foreign body sensation after wearing (low comfort). Summary of the Invention

[0005] In view of the above existing situation, the purpose of the present disclosure is to provide a corneal reshaping lens and a design method thereof that can perform personalized design of the lens based on the basic parameters of the target eyeball to make it have good adaptability, good shaping effect, and high wearing comfort.

[0006] To this end, in a first aspect of the present disclosure, there is provided a corneal reshaping lens. The corneal reshaping lens has an inner surface facing the cornea when worn. The inner surface continuously forms an optical zone, a reverse curve zone, and a fitting curve zone from the center outwards. When the corneal reshaping lens is worn, a tear fluid space for accommodating tear fluid is formed between the reverse curve zone and the anterior surface of the cornea. The fitting curve zone contacts the anterior surface of the eyeball for positioning. Taking the central position of the inner surface as a reference point, the vertical distance between a point on the inner surface and the reference point along the height direction of the lens is called the sagittal height. Taking the corneal position corresponding to the reference point as the corneal apex, and taking the preset contact point of the fitting curve zone on the anterior surface of the eyeball when worn as the landing point, the sagittal height H of the landing point L is: H L = H 1 + T c , where H 1 is the distance between the corneal apex and the landing point along the sagittal height direction, T c is the first set distance along the sagittal height direction between the reference point and the corneal apex in the wearing state, and T c > 0. The sagittal height H of the boundary point of the lens in the optical zonep is: H p = H 2 + T c - T p , where H 2 is the distance in the sagittal height direction between the corneal position corresponding to the boundary point of the optical zone and the corneal apex, and T p is the second set distance in the sagittal height direction between the boundary point of the optical zone and the cornea in the wearing state, where T p is greater than T c , and the difference ΔT between T p and T c is set based on the target basic parameters, and the target basic parameters include the refractive power D x of the eyeball, the corneal apex curvature R o , and the corneal eccentricity e. Taking the junction of the reverse curve zone and the fitting curve zone as the reverse edge point, the distance in the sagittal height direction between the reverse edge point and the landing point is A, and the sagittal height H F of the reverse edge point satisfies: H F = H L - A, and A takes any value between 0 and 0.42 mm.

[0007] In the first aspect of the present disclosure, by configuring the sagittal height H L of the landing point as: H L = H 1 + T c , and configuring the first set distance T c between the base point during wearing and the corneal apex to be greater than 0, it can be ensured that the inner surface optical zone during wearing does not contact the cornea, thereby reducing the compression on the cornea and making the height of the lens at the base point position adapt to the height of the target eyeball; by configuring the sagittal height H p of the boundary point of the optical zone as: H p = H 2 + T c - T p , and configuring the second set distance T p in the sagittal height direction between the boundary point and the cornea to be greater than T c , and setting the difference ΔT between T p and T c based on the target basic parameters of the eyeball, the negative pressure attraction of the tear fluid under the lens (i.e., the lens shaping effect) can be adjusted, thereby helping to shape the cornea. Thus, a corneal reshaping lens with good adaptability, good shaping effect and high wearing comfort can be obtained.

[0008] In addition, in the orthokeratology lens according to the first aspect of the present disclosure, optionally, 15 μm ≤ ΔT ≤ 98 μm. When ΔT is within a certain range, the negative pressure attraction of the tear fluid under the lens increases with the increase of ΔT. In this case, selecting ΔT within this range can obtain an appropriate negative pressure attraction of the tear fluid under the lens, which is helpful for shaping the cornea.

[0009] In addition, in the orthokeratology lens according to the first aspect of the present disclosure, optionally, the landing point is located within a range of 0.65 mm to 1.6 mm radially inward from the edge of the orthokeratology lens. Thereby, it is beneficial to improve the wearing comfort of the orthokeratology lens.

[0010] In addition, in the orthokeratology lens according to the first aspect of the present disclosure, optionally, the diameter of the optical zone is 5 mm to 7 mm. In this case, the optical zone of this size can be adapted to the pupil size of ordinary Asian eyes, thereby achieving a good myopia prevention and control effect.

[0011] In addition, in the orthokeratology lens according to the first aspect of the present disclosure, optionally, on the longitudinal section passing through the center of the lens, the fitting arc zone has a tangent segment that can be tangent to the cornea, the landing point is located within the tangent segment, and the width of the tangent segment is 0.5 mm to 1.5 mm. Thereby, the wearing comfort of the orthokeratology lens can be further improved.

[0012] In addition, in the orthokeratology lens according to the first aspect of the present disclosure, optionally, 0 < T c ≤ 20 μm. This ensures that when wearing the orthokeratology lens, the orthokeratology lens does not directly contact the cornea within its optical zone, causing excessive local pressure and thus damaging the tissue on the surface layer of the cornea. At the same time, an appropriate T c effectively ensures that a tear fluid with an appropriate thickness is filled between the optical zone and the corneal surface, which is helpful for shaping the cornea.

[0013] The second aspect of the present disclosure provides a design method for an orthokeratology lens. The orthokeratology lens has an inner surface facing the cornea when worn. The inner surface continuously forms an optical zone, a reverse curve zone, and a fitting arc zone from the center outwards. When the orthokeratology lens is worn, a tear fluid space for accommodating tear fluid is formed between the reverse curve zone and the front surface of the cornea, and the fitting arc zone contacts the front surface of the eyeball for positioning. Taking the center position of the inner surface as the base point, the vertical distance between the point on the inner surface and the base point in the height direction of the lens is called the sagittal height. Taking the cornea corresponding to the base point as the corneal apex, taking the junction of the optical zone and the reverse curve zone as the optical edge point, taking the preset contact point of the fitting arc zone on the front surface of the eyeball when worn as the landing point, and taking the junction of the reverse curve zone and the fitting arc zone as the reverse edge point, the design method includes the following steps:

[0014] Obtain the target basic parameters of the wearer: Based on optometry examination, obtain the target basic parameters, where the target basic parameters include the corrected diopter D of the eyeball x , the corneal apex curvature R o , and the corneal eccentricity e; Set the key point parameters: The key point parameters include the distance H in the sagittal height direction between the corneal apex and the landing point 1 , the distance H in the sagittal height direction between the corneal apex and the corneal position corresponding to the optical edge point 2 , in the wearing state, the first set distance T in the sagittal height direction between the base point and the corneal apex c , and the second set distance T in the sagittal height direction between the corresponding position of the optical edge point and the cornea p , where T c is greater than 0, T p is greater than T c , and the difference between T p and T c is ΔT, and the value of ΔT is set based on the target basic parameters; Set the parameters of the orthokeratology lens: Configure the sagittal height H of the optical edge point p to satisfy H p = H 2 + T c - T p ; Configure the sagittal height H of the landing point L to satisfy H L = H 1 + T c ; Configure the sagittal height H of the reverse edge point F to satisfy: H F = H L - A, where A takes any value between 0 and 0.42 mm.

[0015] In the second aspect of the present disclosure, by configuring the sagittal height H of the landing point L to satisfy H L = H 1 + T c , and configuring the first set distance T between the base point and the corneal apex during wearing to be greater than 0, it can be ensured that the inner surface of the lens does not contact the cornea during wearing, thereby reducing the pressure on the cornea and making the height of the lens at the base point position adapt to the height of the target eyeball; By configuring the sagittal height H of the boundary point of the optical zone c to satisfy H p = H p + T 2 - T c - T p , and the second set distance T in the sagittal height direction between the boundary point and the corneap configured to be greater than T c and T is set based on the target basic parameters of the wearer's eyeball p The difference ΔT from T c can adjust the negative pressure attraction of the tear fluid under the lens (i.e., the lens shaping effect), thereby helping to shape the cornea. Thus, through the design method related to the second aspect of the present disclosure, the lens can be designed based on the target basic parameters of the wearer, and a corneal reshaping lens with good adaptability, good shaping effect and high wearing comfort can be obtained.

[0016] In addition, in the design method related to the second aspect of the present disclosure, optionally, 15μm ≤ ΔT ≤ 98μm. In this case, selecting ΔT within this range can obtain an appropriate negative pressure attraction of the tear fluid under the lens, thereby helping to shape the cornea.

[0017] In addition, in the design method related to the second aspect of the present disclosure, optionally, the set value of ΔT is positively correlated with the correction diopter D x and the corneal apex curvature R o and negatively correlated with the corneal eccentricity e. In this case, ΔT can be set based on the target basic parameters of the wearer's eyeball, which is beneficial to improving the adaptability between the lens and the wearer.

[0018] In addition, in the design method related to the second aspect of the present disclosure, optionally, 0 < T c ≤ 20μm. This ensures that when wearing the corneal reshaping lens, the corneal reshaping lens will not directly contact the cornea in its optical zone, causing excessive local pressure and thus damaging the tissue on the surface of the cornea. At the same time, appropriate T c effectively ensures that there is a tear fluid with an appropriate thickness filled between the optical zone and the corneal surface, thereby helping to shape the cornea.

[0019] In addition, in the design method related to the second aspect of the present disclosure, optionally, the target basic parameters further include the pupil diameter, and the diameter of the optical zone is designed based on the pupil diameter and the correction diopter D x Thus, an optical zone size adapted to the pupil size can be obtained, thereby achieving a good shaping effect.

[0020] In addition, in the design method related to the second aspect of the present disclosure, optionally, when the absolute value of the correction diopter D x is not greater than 4D, the diameter of the optical zone is 0.5mm to 1.2mm larger than the pupil diameter; when the correction diopter D xWhen the absolute value of is greater than 4D, the diameter of the optical zone is 0.3mm to 0.8mm larger than the pupil diameter. Generally speaking, the size of the effective optical zone that can produce an effect when wearing orthokeratology lenses is usually smaller than the size of the optical zone on the inner surface of the lens, and the difference between the effective optical zone and the pupil diameter will affect the effective defocus produced by wearing orthokeratology lenses, thereby regulating the effect of myopia prevention and control; patients with different degrees of refractive error have different feedback on the changes in the optical zone diameter. In this case, based on the correction diopter D x The value of can be used to set the size of the optical zone to obtain a corneal reshaping lens that is further adapted to the eyeball. While satisfying the shaping effect, the larger optical zone of the corneal reshaping lens can also meet the wearer's needs for seeing objects under partial white light conditions.

[0021] In addition, in the design method according to the second aspect of the present disclosure, optionally, the vertex radius R of the optical zone is c satisfy: Among them, D 2 For the set overfocus amount, C is selected from 320 to 350. In this case, by based on the desired correction light D x and overfocus D 2 To design the vertex radius R of the optical zone c , which can help to make the reshaped cornea have normal refractive power.

[0022] In addition, in the design method of the second aspect of the present disclosure, optionally, the landing point is set to be within a range of 0.65 mm to 1.6 mm radially inward from the edge of the orthokeratology lens, thereby improving the wearing comfort of the orthokeratology lens.

[0023] According to the present disclosure, a corneal reshaping lens and a design method thereof can be provided, which have good adaptability to the eyeball, high shaping efficiency and high wearing comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram showing the orthokeratology lens involved in the example of the present disclosure.

[0025] Figure 2 It is a schematic diagram showing the three-dimensional structure of the orthokeratology lens involved in the example of the present disclosure.

[0026] Figure 3 It is shown Figure 2 Schematic diagram of the cross section of the orthokeratology lens along MM'.

[0027] Figure 4 2 is a schematic diagram of a top projection of the orthokeratology lens involved in the example of the present disclosure.

[0028] Figure 5It is a flowchart showing the design method involved in the examples of the present disclosure.

[0029] Figure 6 It is a schematic design diagram of a corneal reshaping lens involved in the examples of the present disclosure.

[0030] Figure 7A It is a schematic diagram showing the state of a corneal reshaping lens attached to the cornea involved in the examples of the present disclosure.

[0031] Figure 7B It shows Figure 7A An enlarged schematic diagram of the S region in

[0032] Explanation of reference numerals:

[0033] 1... Corneal reshaping lens, 20... Outer surface,

[0034] 10... Inner surface, 11... Optical zone, 12... Reverse curve zone,

[0035] 13... Fitting curve zone, 13a... Tangent segment, 30... Elliptical edge, Q... Tilt angle,

[0036] C... Base point, P... Optical edge point, F... Reverse edge point, L... Landing point,

[0037] 2... Cornea, C 1 … Corneal vertex, P 1 … Corneal point. Detailed description of the specific implementation

[0038] All references cited in the present disclosure are incorporated herein by reference in their entirety as if fully set forth. Unless otherwise defined, the technical and scientific terms used in the present disclosure have the same meaning as commonly understood by those of ordinary skill in the art to which the present disclosure pertains.

[0039] Hereinafter, the preferred embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, the same reference numerals are given to the same components, and redundant descriptions are omitted. In addition, the drawings are only schematic diagrams, and the proportional relationship of the sizes between components or the shapes of components may be different from the actual ones.

[0040] It should be noted that the terms "including" and "having" in the present disclosure and any variations thereof, for example, the processes, methods, systems, products, or devices including or having a series of steps or units do not necessarily have to be limited to those steps or units clearly listed, but may include or have other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0041] The first aspect of the present disclosure relates to an orthokeratology lens, which is a contact lens that reshapes the shape of the cornea for vision correction. The orthokeratology lens of the present disclosure can be simply referred to as a lens, or also called an OK lens. Through the orthokeratology lens involved in the present disclosure, it can be well adapted to the eyeball during wearing, with high shaping efficiency and high comfort.

[0042] The second aspect of the present disclosure relates to a design method for an orthokeratology lens. The design method for the orthokeratology lens of the present disclosure can be simply referred to as a design method, or also called a preparation method for an orthokeratology lens. Through the design method of the present disclosure, an orthokeratology lens with good adaptability, good shaping effect and high wearing comfort can be manufactured.

[0043] The following will describe in detail the orthokeratology lens 1 and its design method according to the present embodiment with reference to the accompanying drawings.

[0044] Figure 1 FIG. 10 is a schematic diagram showing the application of the orthokeratology lens 1 according to the example of the present disclosure. Figure 2 FIG. 12 is a schematic perspective view showing the orthokeratology lens 1 according to the example of the present disclosure.

[0045] The orthokeratology lens 1 according to the present embodiment can be applied to the surface of the eyeball. Specifically, the orthokeratology lens 1 can be applied to the front surface of the cornea 2. A tear space T can be formed between the orthokeratology lens 1 and the front surface of the cornea 2. There is a non-uniformly distributed tear layer (tear lens) in the tear space T. The shape of the cornea 2 can be changed due to an external force. For example, the shape of the cornea 2 can be reshaped by the hydrodynamic force generated by the tears contained in the tear space T, so as to enable vision correction. Among them, the change in the shape of the cornea 2 can be reversible, and the shape of the cornea 2 will return to its initial state over time.

[0046] The orthokeratology lens 1 according to the present embodiment can have an inner surface 10 and an outer surface 20. The outer surface 20 can be opposite to the inner surface 10 (see Figure 2 ). In the present embodiment, the inner surface 10 can be concave, and the outer surface 20 can be convex (see Figure 2 ). In addition, when wearing the orthokeratology lens 1, the inner surface 10 of the orthokeratology lens 1 can face the front surface of the cornea 2 (see Figure 1 ). In other words, the orthokeratology lens 1 can have an inner surface 10 that faces the cornea 2 when worn.

[0047] In the present embodiment, the inner surface 10 can be configured to change the shape of the cornea 2. For example, when wearing the orthokeratology lens 1, the inner surface 10 can make the central part of the cornea 2 flatter and make the mid-peripheral part of the cornea 2 steeper.

[0048] In some examples, the inner surface 10 can be configured to change the distribution of the epithelial cells on the anterior surface of the cornea 2. Specifically, when wearing the orthokeratology lens 1, for example, under the action of the hydrodynamic force generated by the tear fluid contained in the tear space T and the pressure generated by the inner surface 10, the distribution of the epithelial cells on the anterior surface of the cornea 2 can be changed, thereby changing the shape of the anterior surface of the cornea 2. The epithelial cells on the anterior surface of the cornea 2 can migrate from the central part of the cornea 2 to the mid-peripheral part of the cornea 2, so that the number of epithelial cell layers in the central part of the cornea 2 decreases, and the central part becomes thinner, while the number of epithelial cell layers in the mid-peripheral part of the cornea 2 increases, and the mid-peripheral part becomes thicker, etc. Thus, the orthokeratology lens 1 can reshape the shape of the anterior surface of the cornea 2, thereby correcting vision.

[0049] Figure 3 is a schematic cross-sectional view of the orthokeratology lens 1 along MM'. Figure 2 The shown schematic cross-sectional view is a cross-sectional view along the sagittal height direction of the lens and passing through the center of the lens. Figure 3 Figure 4 is a schematic top view projection of the orthokeratology lens 1 involved in the examples of the present disclosure. Among them, the sagittal height direction (i.e., the height direction of the lens) can be, for example, Figure 3 the G1G2 direction in

[0050] In this embodiment, the orthokeratology lens 1 can be designed to have an inner surface 10 with multiple arc regions. Specifically, the inner surface 10 of the orthokeratology lens 1 can be formed by connecting multiple arc regions, and the multiple arc regions can be connected from the center outwards. For example, the inner surface 10 can be formed by connecting 3, 4, 5, 6, 7, or 8 arc regions.

[0051] Figure 3 In some examples, the orthokeratology lens 1 can be a three-zone design. Specifically, the inner surface 10 of the orthokeratology lens 1 can have an optical zone 11, a reverse curve zone 12, and a fitting curve zone 13 (see Figure 4 and ). Among them, the optical zone 11, the reverse curve zone 12, and the fitting curve zone 13 can be connected in sequence from the center of the inner surface 10 outwards. In other words, the inner surface 10 can continuously form the optical zone 11, the reverse curve zone 12, and the fitting curve zone 13 from the center outwards. When wearing the orthokeratology lens 1, a tear space T for accommodating tears is formed between the reverse curve zone 12 and the anterior surface of the cornea 2, and the fitting curve zone 13 contacts the anterior surface of the eyeball for positioning.

[0052] Figure 5 Figure 6 is a flowchart showing the design method involved in the examples of the present disclosure. Figure 6 is a design schematic diagram of the orthokeratology lens 1 involved in the examples of the present disclosure. In , the line CG schematically represents the chord length of the landing point L.

[0053] In some examples, the design method of the orthokeratology lens 1 may include: obtaining the target basic parameters of the wearer: obtaining the target basic parameters based on the eye vision examination (step S100); setting key point parameters (step S200); setting the parameters of the orthokeratology lens 1 (step S300) (see Figure 5 ). Thus, the parameters of the orthokeratology lens 1 can be obtained.

[0054] In such Figure 6 In the example shown, the center position of the inner surface 10 is taken as the base point C, and the cornea corresponding to the base point C is taken as the corneal vertex C. 1 , the junction of the optical zone 11 and the inversion arc zone 12 is the optical edge point P, the preset contact point of the fitting arc zone 13 on the front surface of the eyeball when worn is the landing point L, the junction of the inversion arc zone 12 and the fitting arc zone 13 is the inversion edge point F, and the vertical distance between the point on the inner surface 10 and the base point C in the height direction of the lens is called the sagittal height.

[0055] In some examples, in step S100, the target basic parameters of the wearer's eyeball may be obtained based on an optometry test, for example, by using a corneal topographer.

[0056] In some examples, in step S100, the target basic parameter may include the corrected luminosity D of the eyeball. x , Corneal vertex curvature R o , and corneal eccentricity e.

[0057] In some examples, in step S200, the key point parameters may include the corneal vertex C 1 The distance H from the landing point L along the sagittal direction 1 , and corneal vertex C 1 The corneal position corresponding to the optical edge point P (hereinafter referred to as corneal point P 1 ) along the direction of the arrow height 2 The landing point L can be selected as a position adjacent to the outer edge of the orthokeratology lens. In order to ensure wearing comfort, preferably, the landing point L is set at a position within the range of 0.65mm to 1.6mm radially inward from the edge of the orthokeratology lens 1. More preferably, the landing point L is set at a position within the range of 0.8mm to 1.2mm radially inward from the edge of the orthokeratology lens 1, which will facilitate the orthokeratology lens 1 to provide appropriate tear exchange space and angle at the edge position.

[0058] In some examples, the corneal vertex C 1 The distance H from the landing point L along the sagittal direction 1 , and corneal vertex C 1 Corneal point P1 The distance H in the sagittal height direction 2 The value can be directly read from the corneal topographic height map and obtained.

[0059] In some examples, H 1 can also be calculated from the corneal vertex curvature R o , and the eccentricity e of the corneal 2 at the chord length of the landing point L (abbreviated as the corneal e value at the landing point L). Specifically, it can be calculated according to the formula, where X is the distance between the corneal vertex C 1 and the landing point L in the width direction of the lens (i.e., the radial direction of the lens). Similarly, the value of H 2 can be calculated according to the corneal vertex curvature R o , and the eccentricity e of the corneal 2 at the chord length of the corneal point P 1 .

[0060] In some examples, in step S200, the key point parameters may further include, in the wearing state, the first set distance T 1 in the sagittal height direction between the base point C and the corneal vertex C c , and the second set distance T 1 in the sagittal height direction between the optical edge point P and the corneal point P p . Among them, T c can be configured to be greater than 0, thereby ensuring that when wearing the orthokeratology lens 1, the orthokeratology lens 1 will not directly contact the cornea 2 in its optical zone 11, causing excessive local pressure on the cornea and further damaging the tissue on the surface layer of the cornea. On this basis, preferably, T c is set to not be greater than 20 μm, so as to ensure that the contact lens 1 forms sufficient force to cause the desired deformation of the cornea 2. In some examples, T c can be set to 5 μm, 8 μm, or 12 μm, etc.

[0061] In some examples, T p is configured to be greater than T c . In this case, the thickness of the tear lens corresponding to the optical edge point P is greater than the thickness of the tear lens corresponding to the base point C, which can facilitate the generation of corresponding fluid forces to reshape the shape of the cornea 2, causing the epithelial cells on the front surface of the cornea 2 to migrate from the central part of the cornea 2 to the mid-peripheral part of the cornea 2.

[0062] In some examples, T p and T cThe difference is ΔT, and the value of ΔT is set based on the target basic parameters of the eyeball. The magnitude of ΔT is the main influencing factor for the negative pressure attraction of the tear fluid under the lens (i.e., the lens shaping effect). When ΔT is within a certain range, the negative pressure attraction of the tear fluid under the lens will increase as ΔT increases. In this case, by setting the value of ΔT according to the target basic parameters of the eyeball, the negative pressure attraction of the tear fluid under the lens can be adjusted, thereby helping to shape the cornea 2.

[0063] In some examples, the set value of ΔT can be related to the refractive power D x , the corneal apex curvature R o , and the corneal eccentricity e. Specifically, the set value of ΔT is positively correlated with the refractive power D x , the corneal apex curvature R o and negatively correlated with the corneal eccentricity e.

[0064] Table 1 below schematically lists some corresponding values between ΔT and the refractive power D x , the corneal apex curvature R o , and the corneal eccentricity e (only schematically listed and should not be understood as a necessary choice under the corresponding values). Hereinafter, taking Table 1 as an example, the correlation between ΔT and the refractive power D x , the corneal apex curvature R o , and the corneal eccentricity e will be described.

[0065] Table 1

[0066] <![CDATA[Corrected light intensity D x (D)]]> <![CDATA[Corneal apex curvature R o > Corneal eccentricity e ΔT (μm) -2 7.99 0.8 0.026 -2 7.99 0.7 0.028 -2 7.99 0.6 0.030 -2 7.8 0.8 0.025 -2 7.8 0.7 0.028 -2 7.8 0.6 0.030 -2 7.67 0.8 0.024 -2 7.67 0.7 0.028 -2 7.67 0.6 0.030 -3 7.8 0.8 0.040 -3 7.8 0.7 0.045 -3 7.8 0.6 0.048 -4 7.8 0.8 0.055 -4 7.8 0.7 0.060 -4 7.8 0.6 0.064

[0067] In some examples, the change range corresponding to ΔT and the refractive power D x (±1D) can be greater than the change range corresponding to ΔT and the corneal eccentricity e (±0.1). In some examples, the change range corresponding to ΔT and the corneal eccentricity e (±0.1) can be greater than the change range corresponding to ΔT and the corneal apex curvature R o (±0.1). That is to say, among the three influencing factors (the refractive power D x , the corneal apex curvature R o , and the corneal eccentricity e), the change in the refractive power D x with a step of ±1D has the greatest impact on the set value of ΔT.

[0068] In some examples, when the corneal apex curvature R o and the corneal eccentricity e are certain, the greater the refractive power D x , the greater the value of ΔT. In some examples, ΔT and the refractive power D xThe corresponding change range can be from 0.015 μm:1D to 0.018 μm:1D. That is, when correcting the diopter D x changes in steps of ±1D, the set value of ΔT changes in steps of ±0.015 μm to ±0.018 μm accordingly. Correspondingly, when the corrected diopter D x changes in a step with an absolute value less than 1D, the change step of ΔT also decreases proportionally.

[0069] In some examples, 15 μm ≤ ΔT ≤ 98 μm. In this case, selecting ΔT within this range can obtain an appropriate negative pressure attraction of the tear fluid under the lens, which helps to shape the cornea 2. In some examples, ΔT can be set to 15 μm, 20 μm, 28 μm, 30 μm, 35 μm, 40 μm, 45 μm, 48 μm, 50 μm, 55 μm, 60 μm, 64 μm, 68 μm, 72 μm, 76 μm, 80 μm, 82 μm, 85 μm, 90 μm, 95 μm or 98 μm, etc.

[0070] In some examples, in step S300, the parameters of the orthokeratology lens 1 can be set based on the target basic parameters. Thus, an orthokeratology lens 1 with good adaptability to the target eyeball can be obtained.

[0071] In some examples, in step S300, the sagittal height H p (i.e., the sagittal height of the optical zone 11) of the optical edge point P can be configured to satisfy H p = H 2 + T c - T p . In this case, the sagittal height H p of the optical edge point P designed based on the target basic parameters of the wearer can be obtained, thereby improving the adaptability of the orthokeratology lens 1 to the wearer and facilitating obtaining a good shaping effect.

[0072] In some examples, the optical edge point P can also be referred to as the boundary point of the optical zone 11. That is, the sagittal height H p of the boundary point of the optical zone 11 can satisfy H p = H 2 + T c - T p .

[0073] In some examples, when the value of the sagittal height H p of the optical edge point P is fixed, T p can be selected as large as possible within the optional range. In this case, it is beneficial to enhance the negative pressure attraction of the tear fluid under the lens, thereby improving the shaping effect and shaping efficiency.

[0074] In some examples, in step S300, the elevation H of the landing point L L can be configured to satisfy H L = H 1 + T c . In this case, the elevation H of the landing point L designed based on the target basic parameters of the wearer can be obtained L , thereby improving the matching degree between the orthokeratology lens 1 and the wearer and being beneficial to improving the wearing comfort of the orthokeratology lens 1.

[0075] In some examples, in step S300, the elevation H of the reverse edge point F F can be configured to satisfy: H F = H L - A. Wherein, A can be the distance between the reverse edge point F and the landing point L in the elevation direction. That is to say, the elevation H of the reverse edge point F F can = H 1 + T c - A. Thus, the elevation H of the reverse edge point F designed based on the target basic parameters of the wearer can be obtained F , thereby improving the matching degree between the orthokeratology lens 1 and the wearer.

[0076] In some examples, A can take any value between 0 and 0.42 mm. That is to say, the distance between the reverse edge point F and the landing point L in the elevation direction can take any value between 0 and 0.42 mm. More preferably, A is set to a value within the range of 0.1 mm - 0.3 mm, for example, 0.13 mm, 0.13 mm, 0.16 mm, 0.20 mm. Further, the A values of the orthokeratology lens 1 on its four semi-meridians can be set to different values to match the corneal shape, improve the wearing comfort, and at the same time enhance the shaping effect.

[0077] In some examples, the height h 1 (i.e., the distance between the reverse edge point F and the optical edge point P in the elevation direction) of the reverse arc region 12 can satisfy h 1 = H L - H p - A.

[0078] In some examples, in step S100, the target basic parameters can further include the pupil diameter, and the diameter of the optical zone 11 can be designed based on the pupil diameter and the correction diopter D x . In some examples, the diameter of the optical zone 11 can be designed based on the dark pupil diameter. The dark pupil diameter refers to the pupil diameter of the wearer in a relatively dark environment.

[0079] Generally speaking, the size of the effective optical zone (the effective optical zone is the optical zone after the cornea is reshaped) that can produce an effect when wearing the orthokeratology lens 1 is usually smaller than the size of the optical zone 11 of the inner surface 10 of the lens (the difference is usually about 0.5 mm), and the difference between the effective optical zone and the pupil diameter will affect the effective defocus amount produced by wearing the orthokeratology lens 1, thereby regulating the effect of myopia prevention and control. In some examples, the diameter d of the effective optical zone can satisfy: Among them, the diameter of the effective optical zone d is in mm, t is the difference in corneal height before and after wearing the lens (um), and the corrected diopter D x The unit is D.

[0080] According to the inventor's research, patients with different degrees of refractive error have different feedback on the plastic changes brought about by the change in the diameter of the optical zone 11. Specifically, when the refractive power of the patient with refractive error is not greater than -4D (corresponding to an absolute value of not greater than 4D), the difference in the effective optical zone of the patient with refractive error after correction of optical zones of different diameters is small; conversely, when the refractive power of the patient with refractive error is greater than -4D (corresponding to an absolute value greater than 4D), the difference in the effective optical zone of the patient with refractive error after correction of optical zones of different diameters is large. For this reason, the inventor designed the size of the optical zone 11 as follows: when the corrected diopter D x When the absolute value of the corrected diopter D is not greater than 4D, the diameter of the optical zone 11 can be set to be 0.5 mm to 1.2 mm larger than the pupil diameter; x When the absolute value of is greater than 4D, the diameter of the optical zone 11 can be set to be 0.3mm to 0.8mm larger than the pupil diameter. Thus, while satisfying the shaping effect, the larger optical zone 11 of the orthokeratology lens 1 can meet the wearer's need to see objects under partial white light conditions.

[0081] In some examples, the diameter of the optical zone 11 can also be designed according to the wearer's visual needs. For example, for wearers who have high requirements for daytime visual quality after removing their glasses, the diameter of the optical zone 11 can be designed based on the pupil size and the corrected diopter D. x A larger diameter of the optical zone 11 is selected within the optional range of the designed diameter of the optical zone 11. In this case, the difference between the diameter of the effective optical zone 11 and the pupil diameter can be reduced, thereby reducing the impact of factors such as glare on vision, and thus obtaining better daytime visual quality. For wearers who require a strong myopia prevention and control effect and do not have such high requirements for daytime visual quality after removing the glasses, a smaller diameter of the optical zone 11 can be selected within the optional range of the diameter of the optical zone 11. In this case, the difference between the diameter of the effective optical zone 11 and the pupil diameter can be increased, thereby increasing the effective defocus amount produced by wearing the orthokeratology lens 1, which is conducive to obtaining a stronger myopia prevention and control effect.

[0082] For example, in the corrected photometric D xIn the example where the absolute value of is not greater than 4D and the diameter of the optical zone 11 is 0.5mm to 1.2mm larger than the pupil diameter, for wearers who have high requirements for daytime visual quality after removing their glasses, the diameter of the optical zone 11 can be designed to be 1mm to 1.2mm larger than the pupil diameter; for wearers who require strong myopia prevention and control effects, the diameter of the optical zone 11 can be designed to be 0.5mm to 0.8mm larger than the pupil diameter.

[0083] For example, in the corrected photometric D x In the example where the absolute value of is greater than 4D and the diameter of the optical zone 11 is 0.3mm to 0.8mm larger than the pupil diameter, for wearers who have high requirements for daytime visual quality after removing their glasses, the diameter of the optical zone 11 can be designed to be 0.5mm to 0.8mm larger than the pupil diameter; for wearers who require strong myopia prevention and control effects, the diameter of the optical zone 11 can be designed to be 0.3mm to 0.5mm larger than the pupil diameter.

[0084] In some examples, the diameter of the optical zone 11 of the orthokeratology lens 1 may be no greater than 7 mm.

[0085] In some examples, the diameter of the optical zone 11 of the orthokeratology lens 1 may be 5 mm to 7 mm. In this case, the optical zone 11 of this size can be adapted to the pupil size of an average Asian eye, thereby achieving a good myopia prevention and control effect.

[0086] In some examples, the vertex radius R of the optical zone 11 is c Can satisfy: Among them, D 2 For the set overfocus amount, C is selected from 320 to 350. In this case, by based on the desired correction light D x and overfocus D 2 To design the vertex radius R of the optical zone 11 c , which can help to make the reshaped cornea 2 normal in refraction. In some examples, C can be 320, 325, 330, 335, 340, 345, or 350, etc.

[0087] In some examples, the optical zone 11 and the reverse arc zone 12 can be independently designed as any one of a free-form surface, an ellipsoidal surface, or a high-order aspherical surface.

[0088] Figure 7A is a schematic diagram showing a state where the orthokeratology lens 1 involved in the example of the present disclosure is attached to the cornea 2; Figure 7B It shows Figure 7A Enlarged schematic diagram of the middle S region.

[0089] In some examples, such as Figure 7AAs shown, when wearing the orthokeratology lens 1, the fitting arc area 13 can contact the cornea 2. In some examples, on the longitudinal section passing through the center of the lens, the fitting arc area 13 can have a tangent segment 13a that can be tangent to the cornea 2 (see Figure 7B ). The landing point L can be located within the tangent segment 13a. Thus, it can be beneficial to fit the lens to the cornea 2.

[0090] In some examples, the width of the tangent segment 13a can be 0.5 mm to 1.5 mm. Thus, it can be beneficial to improve the wearing comfort of the orthokeratology lens 1.

[0091] In some examples, when wearing the orthokeratology lens 1, the fitting arc area 13 can be tangent to the cornea 2 (see Figure 7A ). Additionally, when wearing the orthokeratology lens 1, the fitting arc area 13 and the cornea 2 can form a tilt angle Q (see Figure 7B ). Thus, the tilt angle Q can be used for tear exchange. In this case, the fitting arc area 13 can not only contact and position with the cornea 2, but also form a gap (i.e., the tilt angle Q) for tear exchange with the cornea 2.

[0092] In some examples, as Figure 7B shown, the fitting arc area 13 can be connected to the outer surface 20 via an elliptical edge 30. In other words, the inner surface 10 and the outer surface 20 of the orthokeratology lens 1 can be connected via the elliptical edge 30. Thus, the inner surface 10 and the outer surface 20 can be smoothly connected to form the complete orthokeratology lens 1.

[0093] In some examples, the orthokeratology lens 1 can be designed with quadrant partitioning. Specifically, by measuring the target basic parameters of each quadrant of the cornea 2 and performing quadrant-specific design on the orthokeratology lens 1 based on the target basic parameters of each quadrant. In this case, since the cornea 2 has quadrant asymmetry, and the quadrant asymmetry of the cornea 2 is more obvious the closer it is to the periphery, the quadrant-specific design can improve the matching of the orthokeratology lens 1 with the cornea 2 in each quadrant. Thus, it can better match the shape of the cornea 2, which helps to improve the reliability and comfort of the orthokeratology lens 1.

[0094] In the present embodiment, the surface shape of the outer surface 20 is not particularly limited. For example, the outer surface 20 can be spherical, aspherical, toric, multifocal, or non-rotationally symmetric geometric shape. In some examples, the surface shape of the outer surface 20 can be the same as the surface shape of the inner surface 10.

[0095] In some examples, after obtaining the parameters of the orthokeratology lens 1 according to the design method described above, an orthokeratology lens 1 with good adaptability, good shaping effect, and high wearing comfort can be manufactured.

[0096] In some examples, the specific parameters and structure of the orthokeratology lens 1 related to the present disclosure are consistent with the lens prepared according to the design method of the orthokeratology lens related to the present disclosure, and will not be elaborated herein.

[0097] In summary, according to the present disclosure, an orthokeratology lens 1 and its design method can be provided, which can perform personalized design on the lens based on the basic parameters of the target eyeball, so that it has good adaptability, good shaping effect and high wearing comfort.

[0098] Although the present disclosure has been specifically described above in conjunction with the accompanying drawings and embodiments, it can be understood that the above description does not limit the present disclosure in any form. Those skilled in the art can make deformations and changes to the present disclosure according to needs without departing from the essence and scope of the present disclosure, and these deformations and changes all fall within the scope of the present disclosure.

Claims

1. A corneal reshaping lens, which has an inner surface facing the cornea when worn. It is characterized in that: The inner surface continuously forms an optical zone, a reverse curve zone, and a fitting curve zone from the center outwards. When the corneal reshaping lens is worn, a tear space for accommodating tears is formed between the reverse curve zone and the anterior surface of the cornea, and the fitting curve zone contacts the anterior surface of the eyeball for positioning. Taking the central position of the inner surface as the reference point, the vertical distance between the point on the inner surface and the reference point in the height direction of the lens is called the sagittal height. Taking the corneal position corresponding to the reference point as the corneal vertex and the preset contact point of the fitting arc area on the anterior surface of the eyeball during wearing as the landing point, the sagittal height H of the landing point L is: H L =H 1 +T c , where H 1 is the distance between the corneal vertex and the landing point in the sagittal height direction, and T c is the first set distance between the reference point and the corneal vertex in the sagittal height direction in the wearing state, and T c >0 The sagittal height H of the boundary point of the lens in the optical zone p is: H p =H 2 +T c -T p , where H 2 is the distance in the sagittal height direction between the corneal position corresponding to the boundary point of the optical zone and the corneal vertex, and T p is the second set distance in the sagittal height direction between the boundary point of the optical zone and the cornea in the wearing state, where T p is greater than T c , and the difference ΔT between T p and T c is set based on the target basic parameters. The target basic parameters include the corrected diopter D x of the eyeball, the corneal vertex curvature R o , and the corneal eccentricity e. The set value of ΔT is positively correlated with the corrected diopter D x and the corneal vertex curvature R o and negatively correlated with the corneal eccentricity e Taking the junction of the reverse arc area and the fitting arc area as the reverse edge point, the distance between the reverse edge point and the landing point in the sagittal height direction is A, and the sagittal height of the reverse edge point is H F Satisfy: H F =H L -A, where A takes any value between 0 and 0.42 mm.

2. The corneal reshaping lens according to claim 1. It is characterized in that: 15μm ≤ ΔT ≤ 98μm.

3. The corneal reshaping lens according to claim 1. It is characterized in that: The landing point is located within the range of 0.65 mm to 1.6 mm radially inwards from the edge of the corneal reshaping lens.

4. The corneal reshaping lens according to claim 1. It is characterized in that: The diameter of the optical zone is 5 mm to 7 mm.

5. The corneal reshaping lens according to claim 1. It is characterized in that: On the longitudinal section passing through the center of the lens, the fitting curve zone has a tangent segment that can be tangent to the cornea. The landing point is located within the tangent segment, and the width of the tangent segment is 0.5 mm to 1.5 mm.

6. The corneal reshaping lens according to any one of claims 1-5. It is characterized in that: 0 < T c ≤ 20 μm.

7. A design method for a corneal reshaping lens, which has an inner surface facing the cornea when worn. The inner surface continuously forms an optical zone, a reverse curve zone, and a fitting curve zone from the center outwards. When the corneal reshaping lens is worn, a tear space for accommodating tears is formed between the reverse curve zone and the anterior surface of the cornea, and the fitting curve zone contacts the anterior surface of the eyeball for positioning. Taking the central position of the inner surface as the reference point, the vertical distance between the point on the inner surface and the reference point in the height direction of the lens is called the sagittal height. Taking the cornea corresponding to the reference point as the corneal apex, taking the junction of the optical zone and the reverse curve zone as the optical edge point, taking the preset contact point of the fitting curve zone on the anterior surface of the eyeball when worn as the landing point, and taking the junction of the reverse curve zone and the fitting curve zone as the reverse edge point. It is characterized in that The design method includes the following steps: Obtain the target basic parameters of the wearer: Based on optometry examination, obtain the target basic parameters, where the target basic parameters include the corrected diopter D of the eyeball x , the corneal vertex curvature R o , and the corneal eccentricity e; Set key point parameters: The key point parameters include the distance H in the sagittal height direction between the corneal apex and the landing point 1 , the distance H in the sagittal height direction between the corneal apex and the corneal position corresponding to the optical edge point 2 , in the wearing state, the first set distance T in the sagittal height direction between the base point and the corneal apex c , and the second set distance T in the sagittal height direction between the corresponding position of the optical edge point and the cornea p , where T c is greater than 0, T p is greater than T c , and the difference between T p and T c is ΔT, the value of ΔT is set based on the target basic parameters, and the set value of ΔT is positively correlated with the correction diopter D x , the corneal apex curvature R o and is negatively correlated with the corneal eccentricity e; Set the parameters of the orthokeratology lens: Set the sagittal height H of the optical edge point p to satisfy H p =H 2 +T c -T p ; Set the sagittal height H of the landing point L to satisfy H L =H 1 +T c ; Set the sagittal height H of the reverse edge point F to satisfy: H F =H L -A, where A takes any value between 0 and 0.42 mm.

8. The design method for a corneal reshaping lens according to claim 7. It is characterized in that: 15μm ≤ ΔT ≤ 98μm.

9. The design method for a corneal reshaping lens according to claim 7. It is characterized in that: 0 < T c ≤ 20 μm.

10. The design method for a corneal reshaping lens according to claim 7. It is characterized in that: The target basic parameters further include the pupil diameter, and the diameter of the optical zone is based on the pupil diameter and the refractive power D x Design 11. The design method for a corneal reshaping lens according to claim 10. It is characterized in that: When the absolute value of the corrective diopter D x is not greater than 4 D, the diameter of the optical zone is 0.5 mm to 1.2 mm larger than the pupil diameter; when the absolute value of the corrective diopter D x is greater than 4 D, the diameter of the optical zone is 0.3 mm to 0.8 mm larger than the pupil diameter.

12. The design method for a corneal reshaping lens according to claim 7. It is characterized in that: The vertex radius R of the optical zone c satisfies: R c = ; where D 2 is the set defocus amount, and C is selected from 320 to 350.

13. The design method for a corneal reshaping lens according to claim 7. It is characterized in that: The landing point is set within the range of 0.65 mm to 1.6 mm radially inwards from the edge of the corneal reshaping lens.

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