Corneal contact lens and design method thereof

Abstract

The present disclosure describes a design method for a corneal contact lens, and a corneal contact lens prepared by the design method, the design method comprising: based on a corneal topographer, setting an original curve of the inner surface of a corneal contact lens for correcting ametropia, selecting a plurality of reference points of not less than 2 on the original curve, the plurality of reference points at least including a first reference point and a second reference point, trying on the corneal contact lens in an initial state, and adjusting the vertical distance of the second reference point from the X-axis based on the trial result, designing the edge warping area to meet a preset curve, the preset curve passes through the first reference point and the adjusted second reference point, and at the first reference point, the first-order derivative of the preset curve is equal to the first-order derivative of the original curve. According to the present disclosure, a design method for a corneal contact lens capable of improving wearing comfort, and a corneal contact lens prepared by the design method can be provided.

Description

Technical Field

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

[0002] Rigid gas permeable corneal contact lenses (RGP) are safe and effective contact lenses used for refractive correction, especially for patients with large astigmatism. They are worn on the ocular surface using the siphon principle, do not directly wear the cornea, cause less damage to the cornea, and can be worn for a long time. In recent years, due to the synthesis and application of polymer materials with high Dk value, high elastic modulus, hydrophilicity, anti-precipitation and good biocompatibility, rigid corneal contact lenses have been rapidly popularized around the world.

[0003] In order to ensure sufficient tear exchange when wearing RGP, it is usually necessary to design the edge warping area of ​​the lens. In the prior art, a method of splicing multiple arcs is usually adopted to make the inner surface of the edge warping area of ​​the lens match the cornea as much as possible.

[0004] However, for the above-mentioned RGP, due to the different arc shapes of each arc, sharp points may be formed at the connection points of the arcs, which may cause unexpected pressure on the cornea and lead to low comfort when worn. In addition, when fitting glasses, it is necessary to adjust the edge warping area according to different target eyes, and when adjusting the arc of the above-mentioned RGP, it is necessary to adjust two or even multiple arcs at the same time. The algorithm is relatively complicated and it is not easy to evaluate the effect after adjustment. Summary of the invention

[0005] In view of the above existing situation, the present disclosure aims to provide a design method of a corneal contact lens for designing an edge warping area to improve wearing comfort, and a corneal contact lens prepared by using the design method.

[0006] To this end, the first aspect of the present disclosure provides a design method for a corneal contact lens, wherein the corneal contact lens has an inner surface that faces the cornea and matches the front surface of the cornea when worn, and an outer surface opposite to the inner surface, wherein the inner surface includes an optical arc area, a peripheral arc area, and an edge arc area surrounding the periphery of the peripheral arc area, which are sequentially formed from the inside to the outside. The design method comprises: in an XZ plane constructed with the sagittal direction of the corneal contact lens as the Z-axis direction, the width direction of the corneal contact lens as the X-axis direction, and the vertex of the inner surface as the origin, On a corneal topographer, an original curve of the inner surface of a corneal contact lens for correcting ametropia is set, a plurality of reference points of not less than 2 are selected on the original curve, the plurality of reference points at least comprising a first reference point and a second reference point, the first reference point being a junction point between the peripheral arc area and the edge warping arc area, the second reference point being a boundary point of the inner surface, the corneal contact lens in an initial state is tried on, and a vertical distance between the second reference point and the X-axis is adjusted based on the trial-wearing result, the edge warping arc area is designed to satisfy a preset curve, and the preset curve satisfies: Wherein, x is the vertical distance from the point on the inner surface to the Z axis, Z(x) is the vertical distance from the point on the inner surface to the X axis, and A i are polynomial coefficients, n is an integer not less than 3, the preset curve passes through the first reference point and the adjusted second reference point, and at the first reference point, the first-order derivative of the preset curve is equal to the first-order derivative of the original curve.

[0007] In the present disclosure, an original curve of the inner surface of a corneal contact lens for correcting refractive errors is set based on a corneal topographer. By selecting a plurality of reference points of not less than 2 on the original curve and adjusting the vertical distance of the reference points from the X-axis according to the trial wearing results, a known first reference point and an adjusted second reference point can be obtained. Then, the edge warping area is designed to satisfy a preset curve, and the preset curve is configured to pass through the first reference point and the adjusted second reference point, and the first-order derivative of the preset curve at the first reference point is equal to the first-order derivative of the original curve. Based on the coordinates of the plurality of reference points of not less than 2 and configuring the preset curve so that the first-order derivative of the preset curve at the first reference point is equal to the first-order derivative of the original curve, each A can be deduced. i The value of can be fitted to obtain a continuous and smooth preset curve, i.e., the design curve of the edge warping arc area, thereby, a corneal contact lens with high adaptability to the target human eye and high wearing comfort can be obtained by design. In addition, when fitting the glasses, by adjusting the vertical distance between the second reference point and the X-axis, it is easy to predict the effect of the adjustment. For example, when the trial fitting result shows that the lens is too tight, the vertical distance between the second reference point and the X-axis can be reduced to make the adjusted corneal contact lens fit the target human eye.

[0008] In addition, in the design method involved in the present disclosure, optionally, the trial fitting result includes the distribution of the fluorescent band under the slit lamp fluorescence detection. In this case, the matching of the corneal contact lens of this form with the target human eye can be obtained according to the distribution of the fluorescent band obtained during the trial fitting, and adjusting the vertical distance of the second reference point from the X-axis based on the matching condition can make the lens better fit the target human eye.

[0009] In addition, in the design method involved in the present disclosure, optionally, in the X-axis direction, when the width of the fluorescent band is greater than 1 mm, the first reference point and / or the second reference point is adjusted to be farther away from the X-axis; and / or in the X-axis direction, when the width of the fluorescent band is less than 0.5 mm, the first reference point and / or the second reference point is adjusted to be closer to the X-axis. In this case, the reason why the width of the fluorescent band is greater than 1 mm includes that the lens of this form is looser than the target human eye (that is, the fit between the edge arc area and the cornea is smaller). At this time, by adjusting the first reference point and / or the second reference point to be farther away from the X-axis, the fit between the edge arc area and the cornea can be increased, so that the adjusted corneal contact lens is adapted to the target human eye and the wearing comfort can be improved; and the reason why the width of the fluorescent band is less than 0.5 mm includes that the lens of this form is tighter than the target human eye (that is, the fit between the edge arc area and the cornea is too high, which will produce excessive pressure on the cornea). At this time, by adjusting the first reference point and / or the second reference point to be closer to the X-axis, the pressure of the edge arc area on the cornea can be reduced, so that the adjusted corneal contact lens is adapted to the target human eye, and tear exchange is beneficial, which can improve the wearing comfort.

[0010] In addition, in the design method involved in the present disclosure, optionally, after adjustment, the second reference point in different quadrants has a different vertical distance from the X-axis. In this case, since the human eye usually has different shapes in different quadrants, by adjusting the vertical distance from the second reference point in different quadrants to the X-axis, the edge arc area of ​​each quadrant can be better matched to the shape of the cornea of ​​each quadrant, that is, it can better contact and fit with the cornea of ​​each quadrant, thereby helping to evenly disperse the pressure caused by the corneal contact lens on the cornea, and facilitating tear exchange, thereby improving the safety and comfort of the corneal contact lens.

[0011] In addition, in the design method involved in the present disclosure, optionally, the vertical distance between the first reference point and the Z axis is also adjusted based on the distribution of the fluorescent band under the slit lamp fluorescence detection. In this case, the distribution of the fluorescent band can also be used to determine whether the size of the corneal contact lens of this form is suitable for the target human eye, and then the vertical distance between the first reference point and the Z axis is adjusted based on the adaptation condition to make the corneal contact lens better fit the target human eye.

[0012] In addition, in the design method involved in the present disclosure, optionally, in the X-axis direction, when the width of the fluorescent band is greater than 1 mm, the first reference point is adjusted to be farther away from the Z axis; and / or in the X-axis direction, when the width of the fluorescent band is less than 0.5 mm, the first reference point is adjusted to be closer to the Z axis. In this case, the reason why the width of the fluorescent band is greater than 1 mm includes that the edge warp zone of this form of corneal contact lens is too wide relative to the target human eye in the X-axis direction. At this time, by adjusting the first reference point to be farther away from the Z-axis, the width of the edge warp zone can be reduced, and the fit between the edge warp zone and the cornea can be increased, so that the adjusted corneal contact lens is adapted to the target human eye and the wearing comfort can be improved; and the reason why the width of the fluorescent band is less than 0.5 mm includes that the edge warp zone of this form of corneal contact lens is too narrow relative to the target human eye in the X-axis direction. At this time, by adjusting the first reference point to be closer to the Z-axis, the width of the edge warp zone can be increased, which helps to evenly disperse the pressure caused by the cornea of ​​the cornea and helps tear exchange, thereby improving the safety and comfort of the corneal contact lens.

[0013] In addition, in the design method involved in the present disclosure, optionally, after adjustment, the vertical distances from the first reference point in different quadrants to the Z axis are different. In this case, since the human eye usually has different shapes in different quadrants, by adjusting the vertical distances from the first reference point in different quadrants to the Z axis, the edge arc area of ​​each quadrant can be better matched to the shape of the cornea of ​​each quadrant, that is, it can better contact and fit with the cornea of ​​each quadrant, thereby helping to evenly disperse the pressure caused by the corneal contact lens on the cornea, and facilitating tear exchange, thereby improving the safety and comfort of the corneal contact lens.

[0014] In addition, in the design method involved in the present disclosure, optionally, the dispersion degree of the multiple reference points is adjusted based on the distribution of the fluorescent band under the slit lamp fluorescence detection. In this case, by making the multiple reference points densely distributed in certain specific areas, the preset curve in the area can be further adjusted, so that the edge arc area is better adapted to the cornea; and making the multiple reference points sparsely distributed in certain specific areas can reduce the required calculation amount, thereby improving the efficiency of fitting glasses.

[0015] In addition, in the design method involved in the present disclosure, optionally, in the X-axis direction, when the width of the fluorescent band is greater than 1 mm, the multiple reference points gradually become denser from the inside to the outside; and / or in the X-axis direction, when the width of the fluorescent band is less than 0.5 mm, the multiple reference points gradually become sparser from the inside to the outside. The reasons why the width of the fluorescent band is greater than 1mm include that the corneal contact lens of this form is too loose or too wide relative to the cornea. In this case, the boundary point of the inner surface and the cornea are less matched than the boundary point of the edge arc zone and the peripheral arc zone. At this time, by configuring multiple reference points to be gradually dense along the direction from the inside to the outside, the part of the edge arc zone that is relatively close to the boundary point of the inner surface can be more finely adjusted, so that the edge arc zone as a whole can be better adapted to the cornea; and the reasons why the width of the fluorescent band is less than 0.5mm include that the corneal contact lens of this form is too tight or too narrow relative to the cornea. In this case, compared with the boundary point of the inner surface, the boundary point of the edge arc zone and the peripheral arc zone is less matched with the cornea. At this time, by configuring multiple reference points to be gradually sparse along the direction from the inside to the outside, the part of the edge arc zone that is relatively close to the boundary point of the edge arc zone and the peripheral arc zone can be more finely adjusted, so that the edge arc zone as a whole can be better adapted to the cornea.

[0016] In addition, in the design method involved in the present disclosure, optionally, in the X-axis direction, the distance between the second reference point after adjustment and the second reference point before adjustment is taken from any value in the range of -0.5mm to 0.5mm. In this case, by setting the adjustment range of the second reference point to -0.5mm to 0.5mm, the adjusted edge arc area can be matched with the cornea, which can not only meet the needs of tear exchange, but also have a good wearing effect (for example, it can reduce the undesirable foreign body sensation caused by excessive tilting when wearing).

[0017] In addition, in the design method of the present disclosure, optionally, the multiple reference points further include a third reference point, and the third reference point is the midpoint of the original curve along the X-axis direction or the midpoint along the Z-axis direction. In this case, the preset curve can be further adapted to the cornea, thereby improving the wearing comfort.

[0018] In addition, in the design method involved in the present disclosure, optionally, when worn, the junction point contacts the front surface of the cornea. In this case, the position of the first reference point can be conveniently determined based on a corneal topographer.

[0019] In addition, in the design method involved in the present disclosure, optionally, the boundary point of the inner surface and the intersection point are separated by a first predetermined distance in the X-axis direction and a second predetermined distance in the Z-axis direction, wherein the first predetermined distance is 0.3 mm to 3 mm, and the second predetermined distance is 0.03 mm to 0.30 mm. In this case, setting the warping height of the edge warping area within this range can meet the tear exchange requirements while also helping to improve wearing comfort.

[0020] The second aspect of the present disclosure provides a corneal contact lens, which is prepared by the design method of the first aspect of the present disclosure, thereby obtaining a corneal contact lens with high adaptability to the target human eye and high wearing comfort.

[0021] According to the present disclosure, a design method for a corneal contact lens capable of improving wearing comfort, and a corneal contact lens manufactured using the design method can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram showing the structure of a corneal contact lens according to an example of the present disclosure.

[0023] Figure 2 2 is a diagram showing an application scenario of the corneal contact lens involved in the example of the present disclosure.

[0024] Figure 3 is a flow chart illustrating a design method involved in examples of the present disclosure.

[0025] Figure 4 is a schematic diagram showing the design of the inner surface of a corneal contact lens involved in an example of the present disclosure.

[0026] Figure 5 is a schematic diagram showing adjustment of a reference point according to an example of the present disclosure.

[0027] Fig. 6A is a schematic diagram showing an inner surface to which examples of the present disclosure relate.

[0028] Figure 6B is a schematic diagram showing the partition design of the edge warping area involved in the example of the present disclosure.

[0029] Figure 6C 2 is a schematic diagram showing an edge warp zone designed by partitioning on an XZ plane according to an example of the present disclosure.

[0030] Description of reference numerals:

[0031] 1…contact lens, 2…cornea, 10…outer surface, 20…inner surface, 21…optical arc zone, 22…peripheral arc zone, 23…edge warping arc zone. DETAILED DESCRIPTION

[0032] All references cited in this disclosure are incorporated by reference in their entirety as if fully set forth. Unless otherwise defined, technical and scientific terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0033] Hereinafter, the preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same symbols are assigned to the same components, and repeated descriptions are omitted. In addition, the accompanying drawings are only schematic diagrams, and the ratio of the dimensions of the components or the shapes of the components may be different from the actual ones.

[0034] The present disclosure relates to a design method for a corneal contact lens, and a corneal contact lens prepared by the design method. The design method for a corneal contact lens of the present disclosure can be referred to as a design method, or as a calculation method, a preparation method, etc. The corneal contact lens of the present disclosure can be referred to as RGP, multifocal RPG, contact lens, etc. Through the design method involved in the present disclosure, the inner surface corresponding to the edge warping area of ​​the corneal contact lens can be designed to be a continuous and smooth surface adapted to the cornea of ​​the target human eye, thereby improving the wearing comfort of the corneal contact lens.

[0035] Figure 1 1 is a schematic diagram showing the structure of a corneal contact lens 1 according to an example of the present disclosure. Figure 2 2 is a diagram showing an application scenario of the corneal contact lens 1 involved in the example of the present disclosure.

[0036] In this embodiment, the corneal contact lens 1 may have an inner surface 20 facing the cornea 2 when worn, and an outer surface 10 opposite to the inner surface 20 (see Figure 1 and Figure 2 ). Wherein, the inner surface 20 can match the front surface of the cornea. In this case, it can be helpful to improve the wearing comfort of the corneal contact lens 1.

[0037] In some examples, the inner surface 20 includes an optical arc area 21, a peripheral arc area 22, and an edge arc area 23 surrounding the periphery of the peripheral arc area 22, which are sequentially formed from the inside to the outside (see Figure 1 ).

[0038] In some examples, the contact lens 1 can be configured such that when worn on the eyeball, a tear space can be formed between the inner surface 20 and the cornea 2 (see Figure 2 ). Thus, the abrasion of the cornea 2 by the contact lens 1 can be reduced, thereby improving the wearing comfort. In some examples, the tear space can be filled with tears or therapeutic liquid. In some examples, the edge arc area 23 can be tilted outward to facilitate tear exchange when worn.

[0039] Figure 3 is a flowchart illustrating a design method involved in an example of the present disclosure; Figure 4 2 is a schematic diagram showing the design of the inner surface 20 of the corneal contact lens 1 according to an example of the present disclosure. Figure 3 and Figure 4 , a design method of the corneal contact lens 1 involved in the example of the present disclosure is described.

[0040] In this embodiment, the design method of the corneal contact lens 1 may include: establishing an XZ plane with the sagittal direction of the corneal contact lens 1 as the Z-axis direction, the width direction of the corneal contact lens 1 as the X-axis direction, and the vertex of the inner surface 20 as the origin (S100);

[0041] In the XZ plane, based on the corneal topograph, an original curve of the inner surface 20 of the corneal contact lens 1 for correcting refractive errors is set (S200);

[0042] Selecting a plurality of reference points of no less than 2 on the original curve, wherein the plurality of reference points at least includes a first reference point and a second reference point (S300);

[0043] Performing a trial fitting of the corneal contact lens 1 in the initial state, and adjusting the vertical distance between the second reference point and the X-axis based on the trial fitting result (S400);

[0044] The edge warping arc area 23 is designed to satisfy a preset curve, and the preset curve satisfies:

[0045]

[0046] The preset curve passes through the first reference point and the adjusted second reference point, and at the first reference point, the first-order derivative of the preset curve is equal to the first-order derivative of the original curve (S500) (see Figure 3 ). In step S500, x is the vertical distance between a point on the inner surface 20 and the Z axis, Z(x) is the vertical distance between a point on the inner surface 20 and the X axis, and A i is a polynomial coefficient, and n is an integer not less than 3. In this case, based on the coordinates of a plurality of reference points not less than 2, and configuring the preset curve so that the first-order derivative of the preset curve at the first reference point is equal to the first-order derivative of the original curve, each A can be deduced. iThe value of can be fitted to obtain a continuous and smooth preset curve (i.e., the design curve of the edge warping arc area 23), thereby, a corneal contact lens 1 with high adaptability to the target human eye and high wearing comfort can be obtained by design. In addition, when fitting the glasses, by adjusting the vertical distance between the second reference point and the X-axis, it is easy to predict the effect of the adjustment. For example, when the trial wearing result shows that the lens is too tight, the vertical distance between the second reference point and the X-axis can be reduced to make the adjusted corneal contact lens 1 fit the target human eye.

[0047] In some examples, in step S200, the original curve may be obtained based on the vision that needs to be corrected. Specifically, the diopter may be obtained based on the results of an eye examination. In the present disclosure, the original curve may also be referred to as an optical curve.

[0048] In some examples, in step S300, the first reference point may be a junction point P10 (see Figure 4 In some examples, in step S300, the second reference point may be a boundary point P20 of the inner surface 20 (see Figure 4 ).

[0049] In some examples, when worn, the junction point of the peripheral arc area 22 and the edge warping arc area 23 may contact the front surface of the cornea 2. In this case, the position of the first reference point can be conveniently determined based on a corneal topographer.

[0050] In some examples, the intersection point of the peripheral arc zone 22 and the edge arc zone 23 and the boundary point of the inner surface 20 may be separated by a first predetermined distance in the X-axis direction and a second predetermined distance in the Z-axis direction. In other words, the first reference point and the second reference point may be separated by a first predetermined distance in the X-axis direction and a second predetermined distance in the Z-axis direction. Preferably, the above-mentioned first predetermined distance may be 0.3mm to 3mm, and the second predetermined distance may be 0.03mm to 0.30mm. In this case, setting the lift height of the edge arc zone 23 within this range can not only meet the tear exchange requirements, but also help to improve the wearing comfort.

[0051] In some examples, in step S300, the multiple reference points further include a third reference point, which is the midpoint of the original curve along the X-axis direction or the midpoint along the Z-axis direction. In this case, the preset curve can be further adapted to the cornea 2, improving the wearing comfort.

[0052] In some examples, in step S300, the number of the multiple reference points may be no less than 2. For example, the number of the multiple reference points may be 2, 3, 4, 5, 6, 7, 8, 9, 10 or more. In this case, the more reference points are selected, the higher the matching degree between the preset curve obtained by fitting and the cornea 2 is.

[0053] In some examples, as described above, in step S400, the contact lens 1 in the initial state may be tried on, and the vertical distance between the second reference point and the X-axis may be adjusted based on the trial-fitting result. The contact lens 1 in the initial state refers to the contact lens 1 whose inner surface 20 conforms to the original curve. In this case, by adjusting the vertical distance between the second reference point and the X-axis based on the trial-fitting result, the edge warping area 23 may be adapted to the shape of the cornea 2.

[0054] In some examples, in step S400, in the X-axis direction, the distance between the adjusted second reference point and the second reference point before adjustment can be any value in the range of -0.5mm to 0.5mm, such as -0.2mm, 0.3mm, and so on. "0.5mm" means that the second reference point before adjustment is adjusted 0.5mm away from the X-axis; "-0.5mm" means that the second reference point before adjustment is adjusted 0.5mm in the direction of the X-axis. Advantageously, by setting the adjustment range of the second reference point to -0.5mm to 0.5mm, the adjusted edge arc area 23 is matched with the cornea 2, which can not only meet the needs of tear exchange, but also have a good wearing effect (for example, it can reduce the unwanted foreign body sensation caused by excessive tilting during wearing).

[0055] In some examples, in step S400, the fitting result may include the distribution of the fluorescent band under the slit lamp fluorescence detection. In this case, the matching of the corneal contact lens 1 of the form and the target human eye can be obtained according to the distribution of the fluorescent band obtained during the fitting. For example, it can be judged whether the corneal contact lens 1 of the form is too loose or too tight relative to the target human eye according to the thickness of the fluorescent band, and then the vertical distance of the second reference point from the X-axis is adjusted based on the matching condition to make the lens better fit the target human eye.

[0056] It should be noted that, although the distribution of the fluorescent band is used as a reference for adjusting the multiple reference points in the examples disclosed herein, in many cases, other parameters may also be combined for adjustment. For example, in some examples, in step 400, the trial wearing result may also include the experience of the trial wearer. In this case, the positions of the multiple reference points may be adjusted today in combination with the distribution of the reference fluorescent band and the experience of the trial wearer, so that the corneal contact lens 1 can be further adapted to the target human eye.

[0057] In some examples, in step S400, in the X-axis direction, when the width of the fluorescent band is greater than 1 mm, the first reference point and / or the second reference point can be adjusted to be farther from the X-axis. In this case, the reason why the width of the fluorescent band is greater than 1 mm includes that the lens of this form is looser than the target human eye (i.e., the fit between the edge warp area 23 and the cornea 2 is smaller). At this time, by adjusting the first reference point and / or the second reference point to be farther from the X-axis, the fit between the edge warp area 23 and the cornea 2 can be increased, so that the adjusted corneal contact lens 1 is adapted to the target human eye, which can improve the wearing comfort.

[0058] In some examples, in step S400, in the X-axis direction, when the width of the fluorescent band is less than 0.5 mm, the first reference point and / or the second reference point can be adjusted to be closer to the X-axis. In this case, the reason why the width of the fluorescent band is less than 0.5 mm includes that the lens of this form is tighter than the target human eye (i.e., the fit between the edge arc area 23 and the cornea 2 is too high, which will produce excessive pressure on the cornea 2). At this time, by adjusting the first reference point and / or the second reference point to be closer to the X-axis, the pressure of the edge arc area 23 on the cornea 2 can be reduced, so that the adjusted corneal contact lens 1 is adapted to the target human eye, and is conducive to tear exchange, which can improve the wearing comfort.

[0059] In some examples, in step S400, in the X-axis direction, when the width of the fluorescent strip is greater than 1 mm or less than 0.5 mm, the first reference point and the second reference point may be adjusted simultaneously.

[0060] In some examples, in step S400, in the X-axis direction, when the width of the fluorescent strip is greater than 1 mm or less than 0.5 mm, the vertical distance between the second reference point and the X-axis may be preferentially adjusted.

[0061] Figure 5 is a schematic diagram showing the adjustment of reference points involved in an example of the present disclosure. Figure 5 In order to more clearly illustrate how to adjust the reference points, some lines are omitted.

[0062] In some examples, as described above, when the width of the fluorescent strip is less than 0.5 mm, the second reference point can be adjusted to be closer to the X axis. Figure 5 , L0 is the original curve, and the second reference point P20 located on the original curve L0 can be moved toward the direction close to the X-axis to P21 shown in the figure to obtain the coordinates of the adjusted second reference point P21, and then the preset curve obtained by fitting is roughly the shape shown by L1.

[0063] In some examples, as described above, when the width of the fluorescent strip is greater than 1 mm, the second reference point can be adjusted to be farther from the X axis. Figure 5 , the second reference point P20 located on the original curve L0 can be moved in a direction away from the X-axis to P22 shown in the figure to obtain the coordinates of the adjusted second reference point P22, and then the preset curve obtained by fitting is roughly in the shape shown by L2.

[0064] For some examples, see Figure 5 , P11 is the midpoint of the preset curve L2 along the X-axis direction (i.e., the third reference point). Without adjusting the second reference point P21, the third reference point P11 on the preset curve L2 can be moved toward the direction close to the X-axis to P13 shown in the figure to obtain the coordinates of the adjusted third reference point P13, and the preset curve obtained by fitting is roughly in the shape shown by L3.

[0065] In some examples, in step S400, the vertical distance between the first reference point and the Z axis can also be adjusted based on the distribution of the fluorescent band under the slit lamp fluorescence detection. In this case, the distribution of the fluorescent band can also be used to determine whether the size of the corneal contact lens 1 of this form is suitable for the target human eye, and then the vertical distance between the first reference point and the Z axis is adjusted based on the adaptation condition to make the corneal contact lens 1 better fit the target human eye.

[0066] In some examples, in step S400, in the X-axis direction, when the width of the fluorescent band is greater than 1 mm, the first reference point can be adjusted to be farther from the Z-axis. In this case, the reason why the width of the fluorescent band is greater than 1 mm includes that the edge warp area 23 of the corneal contact lens 1 of this form is too wide relative to the target human eye in the X-axis direction. At this time, by adjusting the first reference point to be farther from the Z-axis, the width of the edge warp area 23 can be reduced, and the fit between the edge warp area 23 and the cornea 2 can be increased, so that the adjusted corneal contact lens 1 is adapted to the target human eye, which can improve the wearing comfort.

[0067] In some examples, in step S400, in the X-axis direction, when the width of the fluorescent band is less than 0.5 mm, the first reference point is adjusted to be closer to the Z-axis. In this case, the reason why the width of the fluorescent band is less than 0.5 mm includes that the edge warp area 23 of the corneal contact lens 1 of this form is too narrow relative to the target human eye in the X-axis direction. At this time, by adjusting the first reference point to be closer to the Z-axis, the width of the edge warp area 23 can be increased, which helps to evenly disperse the pressure caused by the corneal contact lens 1 on the cornea 2 and helps tear exchange, thereby improving the safety and comfort of the corneal contact lens 1.

[0068] In some examples, in step S400, the dispersion of the multiple reference points can also be adjusted based on the distribution of the fluorescent band under the slit lamp fluorescence detection. In this case, by making the multiple reference points densely distributed in certain specific areas, the preset curve in the area can be further adjusted, so that the edge arc area 23 is better adapted to the cornea 2; and making the multiple reference points sparsely distributed in certain specific areas can reduce the required calculation amount, thereby improving the efficiency of eyeglass fitting.

[0069] In some examples, in step S400, in the X-axis direction, when the width of the fluorescent band is greater than 1 mm, multiple reference points can be gradually denser in the direction from the inside to the outside. The reasons why the width of the fluorescent band is greater than 1 mm include that the corneal contact lens 1 of this form is too loose or too wide relative to the cornea 2. In this case, the degree of match between the boundary point of the inner surface 20 and the cornea 2 is lower than that at the junction of the edge arc area 23 and the peripheral arc area 22. At this time, by configuring multiple reference points to be gradually denser in the direction from the inside to the outside, the part of the edge arc area 23 that is relatively close to the boundary point of the inner surface 20 can be more finely adjusted, so that the edge arc area 23 can be better adapted to the cornea 2 as a whole.

[0070] In some examples, in step S400, in the X-axis direction, when the width of the fluorescent band is less than 0.5 mm, multiple reference points can be gradually sparse in the direction from the inside to the outside. The reasons why the width of the fluorescent band is less than 0.5 mm include that the corneal contact lens 1 of this form is too tight or too narrow relative to the cornea 2. In this case, compared with the boundary point of the inner surface 20, the intersection of the edge arc area 23 and the peripheral arc area 22 has a lower degree of match with the cornea 2. At this time, by configuring multiple reference points to be gradually sparse in the direction from the inside to the outside, the part of the edge arc area 23 that is relatively close to the intersection of the edge arc area 23 and the peripheral arc area 22 can be more finely adjusted, so that the edge arc area 23 can be better adapted to the cornea 2 as a whole.

[0071] In some examples, after adjustment, the second reference point in different quadrants has a different vertical distance from the X-axis. After adjustment, the first reference point in different quadrants has a different vertical distance from the Z-axis. In this case, since the cornea 2 of the human eye usually has different shapes in different quadrants, by adjusting the vertical distance of the first reference point from the Z-axis and / or the vertical distance of the second reference point from the X-axis in different quadrants, the edge warp area 23 of each quadrant can be better matched to the shape of the cornea 2 in each quadrant, that is, it can better contact and fit with the cornea 2 in each quadrant, thereby helping to evenly disperse the pressure caused by the corneal contact lens 1 on the cornea 2, and facilitating tear exchange, thereby improving the safety and comfort of the corneal contact lens 1. In other words, the edge warp area 23 can be designed by quadrant partitioning to match the shape of the cornea 2 in different quadrants.

[0072] Fig. 6A is a schematic diagram showing an inner surface 20 to which examples of the present disclosure relate. Figure 6B 2 is a schematic diagram showing the partition design of the edge warping area 23 involved in the example of the present disclosure. Figure 6C 2 is a schematic diagram showing the edge warping area 23 designed by partitioning on the XZ plane involved in the example of the present disclosure. Figure 6B and Figure 6C , Q1 schematically represents the first quadrant, and Q2 schematically represents the second quadrant.

[0073] In some examples, as described above, the inner surface 20 may include an optical arc area 21, a peripheral arc area 22, and an edge arc area 23 surrounding the periphery of the peripheral arc area 22, which are sequentially formed from the inside to the outside (see Fig. 6A ).

[0074] In some examples, the edge warping area 23 can be divided into a plurality of quadrants for quadrant partitioning design. Figure 6B and Figure 6C In the example shown, the edge warping area 23 can be divided into two quadrants (i.e., the first quadrant Q1 and the second quadrant Q2) for quadrant zoning design. The first quadrant Q1 can be a quadrant relatively close to the nose, and the second quadrant Q2 can be a quadrant relatively close to the temporal side. The edge warping area 23a of the first quadrant Q1 and the edge warping area 23b of the second quadrant Q2 can have different shapes to match the shape of the cornea 2 in the corresponding quadrant. In this way, the edge warping area 23 of each quadrant can be better in contact with the cornea 2 of each quadrant, thereby improving the wearing comfort.

[0075] In other examples, the edge warp area 23 can also be divided into 3, 4, 5, 6, 8, 16, or more quadrants for quadrant zoning design. In this case, the more quadrants are divided, the higher the degree of match between the designed corneal contact lens 1 and the cornea 2 of the target human eye. In some examples, preferably, the edge warp area 23 can also be divided into 4 quadrants for zoning design. For example, the edge warp area 23 can also be divided into four quadrants, namely the nasal side, the temporal side, the upper side and the lower side. In this case, both matching accuracy and fitting efficiency can be taken into account at the same time.

[0076] In addition, in some examples, the edge warp region 23 may not have quadrant specificity. For example, the edge warp region 23 may have rotational symmetry.

[0077] In some examples, other arc areas of the inner surface 20 may also be divided into multiple quadrants for quadrant zoning design, so that the inner surface 20 of each quadrant can be adapted to the shape of the cornea 2 of each quadrant.

[0078] In some examples, in step S400, the vertical distance of each reference point from the Z axis can be adjusted by a value in the range of 0.05mm-0.5mm, such as a step of 0.1mm or 0.15mm; in step S400, the vertical distance of each reference point from the X axis can be adjusted by a value in the range of 0.005mm-0.05mm, such as a step of 0.01mm or 0.015mm. In some examples, when the width of the fluorescent band is significantly greater than 1mm (e.g., 2mm or 3mm) or significantly less than 0.5mm (e.g., 0.1mm or 0.2mm), the position of each reference point can also be adjusted by a step of more than 0.5mm, which is conducive to improving the fitting efficiency.

[0079] In some examples, in step S400, the positions of the multiple reference points may be adjusted multiple times. Specifically, after the contact lens 1 in the initial state is tried on and adjusted based on the trial results, the adjusted contact lens 1 may be tried on for a second time, and the positions of the multiple reference points may be adjusted for a second time based on the results of the second trial, and the contact lens 1 after the second adjustment may be tried on for a third time, and the positions of the multiple reference points may be adjusted for a third time based on the results of the third trial, and this may be repeated multiple times until the shape of the contact lens 1 is adapted to the shape of the cornea 2 of the target human eye.

[0080] In some examples, based on the original curve designed by the corneal topographer based on the target human eye, the second reference point on the original curve can be moved by a preset distance in the direction close to the X-axis, and the adjusted preset curve can be fitted before trial fitting. The preset distance can be obtained based on clinical data statistics. In this case, the corneal contact lens 1 obtained after adjustment has a high degree of compatibility with most human eyes. During fitting, the corneal contact lens 1 of this form is used as the initial trial lens for trial fitting, and then the positions of multiple reference points are adjusted based on the trial fitting results, which can reduce the number of times the positions of each reference point need to be adjusted, thereby improving the fitting efficiency.

[0081] In some examples, the preset distance may be 0.05 mm, 0.075 mm, etc.

[0082] In some examples, the corneal contact lens 1 includes an optical zone, a peripheral zone, and an edge warping zone formed sequentially from the inside to the outside. The inner surface 20 corresponding to the optical zone is an optical arc zone 21, the inner surface 20 corresponding to the peripheral zone is a peripheral arc zone 22, and the inner surface 20 corresponding to the edge warping zone is an edge warping arc zone 23.

[0083] In some examples, the center thickness of the corneal contact lens 1 can be selected from any value between 0.10 mm and 1.00 mm. In this case, it is possible to suppress the undesired deformation of the corneal contact lens 1, and at the same time, it is possible to reduce the weight of the corneal contact lens 1, thereby improving the wearing comfort. For example, when the diopter of the corneal contact lens 1 is -25D to 0D, the thickness is 0.10mm to 0.50mm; when the diopter is 0D to +10D, the thickness is 0.20mm to 0.80mm; when the diopter is +10D to +25D, the thickness is 0.40mm to 1.00mm.

[0084] In some examples, the thickness of the edge warping area of ​​the corneal contact lens 1 can be gradually reduced from the inside to the outside. In this case, it can be helpful to improve the wearing comfort.

[0085] In some examples, the outer surface 10 of the corneal contact lens 1 can be designed to have a continuous curved surface based on the sagittal height, thereby facilitating improved wearing comfort.

[0086] In some examples, the corneal contact lens 1 may have a prescription area and a non-prescription area. When the corneal contact lens 1 is worn, light entering the human eye through the prescription area can be focused on the retina, and light entering the human eye through the non-prescription area can be focused in front of the retina. In this way, the progression of myopia can be controlled or delayed, and the need for vision correction can be met.

[0087] In some examples, the contact lens 1 can be formed into a multifocal contact lens 1 through a defocus design (i.e., the contact lens 1 has different diopters in different functional areas through a defocus design). Specifically, the optical zone can be set as a prescription zone, and the peripheral zone can be set as a non-prescription zone. The prescription zone has a diopter for correcting vision, and the non-prescription zone has a diopter different from that of the prescription zone.

[0088] In some examples, the diameter of the contact lens 1 can be set in the range of 8.5 mm to 12.0 mm. For example, the diameter of the contact lens 1 can be 8.5 mm, 8.8 mm, 9 mm, 9.2 mm, 9.6 mm, 10.0 mm, 10.2 mm, 10.5 mm, 10.8 mm, 11 mm, 11.2 mm, 11.5 mm, 11.8 mm or 12 mm.

[0089] In some examples, the contact lens 1 may be made of a hard material. In other examples, the contact lens 1 may be made of a hard high oxygen permeable material. In this case, the contact lens 1 can have good oxygen permeability, improve the wear resistance of the contact lens 1, and facilitate the production of the contact lens 1.

[0090] In some examples, the oxygen permeability coefficient (DK value) of the rigid high oxygen permeability material may be 100 to 200. Thus, it can have good oxygen permeability, so that tears can provide oxygen to the cornea 2, which is beneficial to maintaining the health of the cornea 2. For example, the DK value of the rigid high oxygen permeability material may be 100, 125 or 141. In some examples, the rigid high oxygen permeability material may be one selected from silicone methacrylate, fluorosilicone methacrylate, perfluoroether, and fluorinated silicone.

[0091] Another aspect of the present disclosure relates to a corneal contact lens 1, which is prepared by the design method as described above. Thus, a corneal contact lens with high adaptability to the target human eye and high wearing comfort can be obtained. The various structures and related settings of the corneal contact lens 1 are described in the above-mentioned design method, and will not be repeated here.

[0092] It should be understood that the other parameters of the above contact lenses are only exemplary of the contact lenses formed by the design method of the present invention. In fact, the contact lenses formed by the design method of the present invention can also have other forms. The design method of the present invention provides a method for adjusting the edge warp area. Contact lenses with any form in other areas can obtain edge warp areas that form an elastic band with the cornea, and contact lenses with such edge warp areas according to the design method disclosed by the present invention. As described above, the edge warp areas formed in this way can provide the contact lens with a suitable space for tear exchange and make the contact lens not easy to fall off.

[0093] According to the present disclosure, a corneal contact lens 1 with high wearing comfort and a design method thereof can be provided.

[0094] Although the present disclosure is specifically described above in conjunction with the accompanying drawings and embodiments, it is to be understood that the above description does not limit the present disclosure in any form. Those skilled in the art may modify and change the present disclosure as needed without departing from the essential spirit and scope of the present disclosure, and these modifications and changes all fall within the scope of the present disclosure.

Claims

1. A method for designing a corneal contact lens, characterized in that: The corneal contact lens has an inner surface facing the cornea and matching the front surface of the cornea when worn, and an outer surface opposite to the inner surface, the inner surface includes an optical arc area, a peripheral arc area, and an edge arc area surrounding the periphery of the peripheral arc area, the edge arc area is configured to be tilted outwards to exchange tears when the contact lens is worn; The design method comprises: In an XZ plane constructed with the sagittal direction of the contact lens as the Z-axis direction, the width direction of the contact lens as the X-axis direction, and the vertex of the inner surface as the origin, an original curve of the inner surface of the contact lens for correcting ametropia is set based on a corneal topograph, A plurality of reference points of not less than 2 are selected on the original curve, the plurality of reference points at least including a first reference point and a second reference point, the first reference point being a junction point between the peripheral arc area and the edge warping arc area, and the second reference point being a boundary point of the inner surface, The corneal contact lens in the initial state is tried on, and the vertical distance between the second reference point and the X-axis is adjusted based on the trial wearing result, The edge warping arc area is designed to satisfy a preset curve, and the preset curve satisfies: Wherein, x is the vertical distance from the point on the inner surface to the Z axis, Z(x) is the vertical distance from the point on the inner surface to the X axis, and A i are polynomial coefficients, n is an integer not less than 3, The preset curve passes through the first reference point and the adjusted second reference point, and at the first reference point, a first-order derivative of the preset curve is equal to a first-order derivative of the original curve.

2. The design method according to claim 1, characterized in that: The trial wearing result includes the distribution of fluorescent bands under slit lamp fluorescence detection.

3. The design method according to claim 2, characterized in that: In the X-axis direction, when the width of the fluorescent strip is greater than 1 mm, the first reference point and / or the second reference point is adjusted to be farther from the X-axis; and / or In the X-axis direction, when the width of the fluorescent strip is less than 0.5 mm, the first reference point and / or the second reference point is adjusted to be closer to the X-axis.

4. The design method according to any one of claims 1 to 3, characterized in that: After adjustment, the second reference points in different quadrants have different vertical distances from the X-axis.

5. The design method according to claim 2, characterized in that: The vertical distance between the first reference point and the Z axis is also adjusted based on the distribution of the fluorescent band under slit lamp fluorescence detection.

6. The design method according to claim 5, characterized in that: In the X-axis direction, when the width of the fluorescent strip is greater than 1 mm, the first reference point is adjusted to be farther from the Z-axis; and / or In the X-axis direction, when the width of the fluorescent strip is less than 0.5 mm, the first reference point is adjusted to be closer to the Z-axis.

7. The design method according to claim 5 or 6, characterized in that: After adjustment, the vertical distances of the first reference points in different quadrants from the Z axis are different.

8. The design method according to claim 2, characterized in that: Based on the distribution of the fluorescent bands under slit lamp fluorescence detection, the dispersion degree of the multiple reference points is adjusted.

9. The design method according to claim 8, characterized in that: In the X-axis direction, when the width of the fluorescent strip is greater than 1 mm, the plurality of reference points are gradually denser from inside to outside; and / or In the X-axis direction, when the width of the fluorescent strip is less than 0.5 mm, the plurality of reference points gradually become sparse from inside to outside.

10. The design method according to claim 1, characterized in that: In the X-axis direction, the distance between the second reference point after adjustment and the second reference point before adjustment is any value within the range of -0.5 mm to 0.5 mm.

11. The design method according to claim 1, characterized in that: The multiple reference points further include a third reference point, which is a midpoint of the original curve along the X-axis direction or a midpoint along the Z-axis direction.

12. The design method according to claim 1, characterized in that: When worn, the junction contacts the anterior surface of the cornea.

13. The design method according to claim 1, characterized in that: The boundary point of the inner surface and the intersection point are separated by a first predetermined distance in the X-axis direction and a second predetermined distance in the Z-axis direction, wherein the first predetermined distance is 0.3 mm to 3 mm, and the second predetermined distance is 0.03 mm to 0.3 mm.

14. A corneal contact lens, characterized in that: It is prepared by the design method according to any one of claims 1 to 13.

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