CN115524869A - Corneal contact lens and design method thereof - Google Patents

Abstract

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

Description

Corneal contact lens and design method thereof

Technical Field

The invention relates to the field of medical instruments for ophthalmology, in particular to a corneal contact lens and a design method thereof.

Background

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

In order to ensure adequate tear exchange when RGPs are worn, the limbal region of the lens typically needs to be designed. In the prior art, the inner surface of the lens at the edge warping area is matched with the cornea as much as possible by adopting a multi-segment arc splicing mode.

However, in the RGP, since the arcs of the respective arcs are different, sharp points may be formed at the junctions of the respective arcs, and undesirable pressure may be applied to the cornea, resulting in poor wearing comfort; in addition, when the glasses are matched, the edge warped area needs to be adjusted according to different target human eyes, when the arc of the RGP is adjusted, two or even multiple segments of arcs need to be adjusted at the same time, the algorithm is complex, and the effect after adjustment is not easy to evaluate.

Disclosure of Invention

In view of the above-mentioned conventional circumstances, the present disclosure aims to provide a method for designing a contact lens in which a warped region is designed to improve wearing comfort, and a contact lens manufactured by the designing method.

To this end, the first aspect of the present disclosure provides a method for designing a corneal contact lens, the corneal contact lens having an inner surface facing a cornea during wearing and matching with an anterior surface of the cornea, and an outer surface opposite to the inner surface, the inner surface including an optical arc zone, a peripheral arc zone, and a rim-and-rim arc zone surrounding a periphery of the peripheral arc zone, the method comprising: the sagittal direction of the corneal contact lens is a Z-axis direction, the width direction of the corneal contact lens is an X-axis direction, andin an XZ plane established by taking the vertex of the inner surface as an origin, setting an original curve of the inner surface of a corneal contact lens for correcting ametropia based on a corneal topographer, selecting a plurality of reference points with the number not less than 2 on the original curve, wherein the plurality of reference points at least comprise a first reference point and a second reference point, the first reference point is a junction point of the peripheral arc area and the edge upwarp arc area, the second reference point is a boundary point of the inner surface, trying on the corneal contact lens in an initial state, adjusting the vertical distance between the second reference point and an X axis based on a trying result, designing the edge upwarp arc area to meet a preset curve, and the preset curve meets the following requirements:

wherein X is the perpendicular distance of a point on the inner surface from the Z axis, Z (X) is the perpendicular distance of a point on the inner surface from the X axis, A _i Is a polynomial coefficient, 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 derivative of the preset curve is equal to the first derivative of the original curve.

In the disclosure, an original curve of an inner surface of a corneal contact lens for correcting ametropia is set based on a corneal topographer, a known first reference point and an adjusted second reference point can be obtained by selecting a plurality of reference points with the number not less than 2 on the original curve, adjusting the vertical distance between a reference point and an X axis according to a try-on result, designing a side warping arc area to meet the preset curve, configuring the preset curve to pass through the first reference point and the adjusted second reference point, enabling a first derivative of the preset curve at the first reference point to be equal to a first derivative of the original curve, and enabling the first derivative of the preset curve at the first reference point to be equal to the first derivative of the original curve based on coordinates of the plurality of reference points with the number not less than 2 and configuring the preset curve to be equal to the first derivative of the preset curve at the first reference point, so that the first derivative of the preset curve at the first reference point can be calculated and obtainedEach A is _i The value of (2) can be fitted to obtain a continuous and smooth preset curve, namely a design curve of the edge warping arc area, so that the corneal contact lens which is high in adaptation degree with the target human eye and high in wearing comfort degree can be obtained through design. In addition, the effect of the adjustment can be conveniently predicted by adjusting the vertical distance of the second reference point from the X axis when fitting the lens, for example, when the fitting result is that the lens is too tight, the vertical distance of the second reference point from the X axis can be adjusted to be small so that the adjusted corneal contact lens is adapted to the target human eye.

In addition, in the design method related to the present disclosure, optionally, the fitting result includes a distribution of a fluorescence band under slit-lamp fluorescence detection. In this case, the fitting condition of the corneal contact lens in the form with the target human eye can be obtained according to the distribution condition of the fluorescence bands obtained during the fitting, and the lens can be better fitted to the target human eye by adjusting the vertical distance of the second reference point from the X axis based on the fitting condition.

In addition, in the design method related to the present disclosure, optionally, in the X-axis direction, when the width of the fluorescent strip is greater than 1mm, the first reference point and/or the second reference point is adjusted to be farther from the X-axis; and/or when the width of the fluorescent strip is less than 0.5mm in the X-axis direction, adjusting the first reference point and/or the second reference point to be closer to the X-axis. In this case, the reason that the width of the fluorescent band is greater than 1mm includes that the lens in the shape is looser (i.e., the fitting degree between the edge tilting arc zone and the cornea is smaller) relative to the target human eye, and at this time, the fitting degree between the edge tilting arc zone and the cornea can be increased by adjusting the first reference point and/or the second reference point to be farther away from the X axis, so that the adjusted corneal contact lens is adapted to the target human eye, and the wearing comfort can be improved; the reason that the width of the fluorescent band is less than 0.5mm includes that the lens in the shape is relatively tight relative to target human eyes (namely, the fit degree of the edge tilting arc area and the cornea is too high, and excessive compression can be generated on the cornea), at the moment, the compression of the edge tilting arc area on the cornea can be reduced by adjusting the first reference point and/or the second reference point to be closer to the X axis, so that the adjusted cornea contact lens is adaptive to the target human eyes, tear exchange is facilitated, and the wearing comfort level can be improved.

Additionally, in the design method to which the present disclosure relates, optionally, the vertical distance of the second reference point in different quadrants from the X-axis is different by adjustment. In this case, because the human eye generally has different shapes in different quadrants, the vertical distance from the second reference point in different quadrants to the X axis can be adjusted to enable the edge tilting zone of each quadrant to better match the shape of the cornea of each quadrant, that is, to better contact and fit with the cornea of each quadrant, so that the pressure on the cornea caused by the contact lens can be uniformly dispersed, tear exchange can be facilitated, and the safety and comfort of the contact lens can be improved.

In addition, in the design method related to the present disclosure, optionally, the vertical distance of the first reference point from the Z-axis is further adjusted based on the distribution of fluorescence bands under slit-lamp fluorescence detection. In this case, whether the size of the contact lens in the shape is suitable for the target human eye can be judged according to the distribution condition of the fluorescence bands, and then the vertical distance between the first reference point and the Z axis is adjusted based on the matching condition so that the contact lens is better suitable for the target human eye.

In addition, in the design method related to the present disclosure, optionally, when the width of the fluorescence band is greater than 1mm in the X-axis direction, 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 0.5mm, adjusting the first reference point to be closer to the Z-axis. In this case, the reason that the width of the fluorescence band is greater than 1mm includes that the side warping arc area of the corneal contact lens in the shape is too wide relative to the target human eye in the X-axis direction, and at this time, the width of the side warping arc area can be reduced by adjusting the first reference point to be farther away from the Z-axis, so that the fitting degree of the side warping arc area and the cornea can be increased, the adjusted corneal contact lens is adapted to the target human eye, and the wearing comfort level can be improved; the reason that the width of the fluorescence band is less than 0.5mm includes that the side tilting arc area of the corneal contact lens in the shape is too narrow relative to the target human eye in the X-axis direction, and at the moment, the width of the side tilting arc area can be increased by adjusting the first reference point to be closer to the Z axis, so that the pressure of the corneal contact lens on the cornea is uniformly dispersed, tear exchange is facilitated, and the safety and the comfort of the corneal contact lens can be improved.

Additionally, in the design method to which the present disclosure relates, optionally, the vertical distance of the first reference point in different quadrants from the Z-axis is different by adjustment. In this case, because the human eye generally has different shapes in different quadrants, the vertical distance from the first reference point in different quadrants to the Z axis can be adjusted to enable the edge tilting zone of each quadrant to better match the shape of the cornea of each quadrant, that is, to better contact and fit with the cornea of each quadrant, so that the pressure on the cornea caused by the contact lens can be uniformly dispersed, tear exchange can be facilitated, and the safety and comfort of the contact lens can be improved.

In addition, in the design method according to the present disclosure, optionally, the degree of dispersion of the plurality of reference points is adjusted based on a distribution of fluorescence bands under slit-lamp fluorescence detection. In this case, by densely distributing a plurality of reference points in certain specific regions, the preset curve in the region can be further adjusted, so that the edge tilting zone is better adapted to the cornea; and the plurality of reference points are distributed sparsely in certain specific areas, so that the required calculation amount can be reduced, and the lens matching efficiency is improved.

In addition, in the design method related to the present disclosure, optionally, in the X-axis direction, when the width of the fluorescence band is greater than 1mm, the plurality of reference points are gradually dense along the inside-out direction; and/or in the X-axis direction, when the width of the fluorescence band is less than 0.5mm, the reference points are gradually sparse along the direction from inside to outside. The reason why the width of the fluorescent band is larger than 1mm includes that the corneal contact lens in the shape is too loose relative to the cornea or too wide in size, in this case, compared with the boundary point of the edge warping arc area and the peripheral arc area, the matching degree between the boundary point of the inner surface and the cornea is lower, and at the moment, by configuring a plurality of reference points to be gradually dense along the direction from inside to outside, the part of the boundary point relatively close to the inner surface in the edge warping arc area can be finely adjusted, so that the edge warping arc area can be better adapted to the cornea as a whole; the reason that the width of the fluorescence band is less than 0.5mm includes that the corneal contact lens in the shape is too tight relative to the cornea or too narrow in size, in this case, compared with the boundary point of the inner surface, the matching degree between the boundary point of the edge tilting arc zone and the peripheral arc zone and the cornea is lower, at the moment, the plurality of reference points are configured to be gradually sparse along the direction from inside to outside, the part, relatively close to the boundary point of the edge tilting arc zone and the peripheral arc zone, in the edge tilting arc zone can be finely adjusted, and therefore the edge tilting arc zone can be better adapted to the cornea integrally.

In addition, in the design method according to the present disclosure, optionally, a distance between the adjusted second reference point and the second reference point before adjustment in the X-axis direction is taken from an arbitrary value in a range of-0.5 mm to 0.5mm. In this case, by setting the adjustment range of the second reference point to-0.5 mm to 0.5mm, the adjusted tilted area can be matched with the cornea, thereby satisfying the requirement of tear exchange and achieving a good wearing effect (for example, an undesirable foreign body sensation caused by excessive tilting during wearing can be reduced).

In addition, in the design method according to the present disclosure, optionally, the plurality of reference points further includes a third reference point, where the third reference point is a midpoint of the original curve along the X-axis direction or a midpoint of the original curve along the Z-axis direction. In this case, the preset curve can be further adapted to the cornea, improving comfort of wearing.

Additionally, in the design methods contemplated by the present disclosure, optionally, the interface point is in contact with the anterior surface of the cornea when worn. In this case, the position of the first reference point can be conveniently determined based on the corneal topographer.

In addition, in the design method according to the present disclosure, optionally, a boundary point of the inner surface and the boundary point are separated by a first predetermined distance in the X-axis direction and a second predetermined distance in the Z-axis direction, where the first predetermined distance is 0.3mm to 3mm, and the second predetermined distance is 0.03mm to 0.30mm. Under the condition, the tilting height of the edge tilting arc area is set in the range, so that the requirement of tear exchange can be met, and the wearing comfort level can be improved.

A second aspect of the disclosure provides a contact lens made using the design method of the first aspect of the disclosure. Thus, a contact lens having a high fitting degree with the eye of the subject and a high wearing comfort can be obtained.

According to the present disclosure, a method for designing a contact lens capable of improving wearing comfort, and a contact lens manufactured by the method can be provided.

Drawings

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

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

Fig. 3 is a flow chart illustrating a design method to which an example of the present disclosure relates.

Fig. 4 is a design schematic diagram illustrating the inner surface of a corneal contact lens according to an example of the present disclosure.

Fig. 5 is a schematic diagram illustrating adjustment of a reference point to which examples of the present disclosure relate.

Fig. 6A is a schematic diagram illustrating an inner surface according to an example of the present disclosure.

Fig. 6B is a schematic diagram illustrating a zoning design for a side camber area in accordance with examples of the present disclosure.

Fig. 6C is a schematic diagram illustrating a zoned edge warp arc on the XZ plane in accordance with an example of the present disclosure.

Description of reference numerals:

1 \8230, corneal contact lens 2 \8230, cornea 10 \8230, external surface 20 \8230internalsurface 21 \8230opticalarc area 22 \8230peripheralarc area 23 \8230andedge tilted arc area.

Detailed Description

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

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

The disclosure relates to a design method of a corneal contact lens and a corneal contact lens prepared by the design method. The design method of the corneal contact lens of the present disclosure may be simply referred to as a design method, and may also be referred to as a calculation method, a preparation method, or the like. The corneal contact lenses of the present disclosure may be referred to simply as RGPs, multifocal RPGs, contact lenses, and the like. By the design method, the inner surface corresponding to the edge warping area of the corneal contact lens can be designed into a continuous and smooth surface which is adapted to the cornea of the target human eye, so that the wearing comfort of the corneal contact lens can be improved.

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

In this embodiment, the contact lens 1 may have an inner surface 20 that faces the cornea 2 when worn, and an outer surface 10 opposite the inner surface 20 (see fig. 1 and 2). Wherein the inner surface 20 may match the anterior surface of the cornea. In this case, it is possible to advantageously improve the wearing comfort of the corneal contact lens 1.

In some examples, the inner surface 20 includes an optical arc 21, a peripheral arc 22, and a rim-warp arc 23 (see fig. 1) formed around the periphery of the peripheral arc 22.

In some examples, the contact lens 1 may be configured such that when worn on the eye, a tear space may be formed between the inner surface 20 and the cornea 2 (see fig. 2). This reduces wear of the cornea 2 by the contact lens 1, and improves wearing comfort. In some examples, the tear space may be filled with tears or therapeutic solutions. In some examples, the raised arc region 23 may be raised outward to facilitate tear exchange when worn.

FIG. 3 is a flow chart illustrating a design method to which examples of the present disclosure relate; fig. 4 is a design diagram showing the inner surface 20 of the corneal contact lens 1 according to an example of the present disclosure. Hereinafter, a method of designing the contact lens 1 according to an example of the present disclosure will be described with reference to fig. 3 and 4.

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

setting an original curve of the inner surface 20 of the contact lens 1 for correcting refractive error based on the corneal topographer in the XZ plane (S200);

selecting a plurality of reference points on the original curve, wherein the number of the reference points is not less than 2, and the plurality of reference points at least comprise a first reference point and a second reference point (S300);

fitting the corneal contact lens 1 in an initial state, and adjusting the vertical distance of the second reference point from the X axis based on the fitting result (S400);

the edge warp arc zone 23 is designed to satisfy a preset curve, and the preset curve satisfies:

the preset curve passes through the first reference point and the adjusted second reference point, and at the first reference point, a first derivative of the preset curve is equal to a first derivative of the original curve (S500) (see fig. 3). Wherein, in step S500, X is the vertical distance of the point on the inner surface 20 from the Z axis, Z (X) is the vertical distance of the point on the inner surface 20 from the X axis, A _i Is a polynomial coefficient, and n is an integer of not less than 3. In the case of this situation, it is,based on the coordinates of a plurality of reference points with the number not less than 2 and the preset curve is configured to make the first derivative of the preset curve equal to the first derivative of the original curve at the first reference point, each A can be calculated _i The value of (a) can be fitted to obtain a continuous and smooth preset curve (i.e. the design curve of the edge warping arc area 23), so that the corneal contact lens 1 with high fitting degree and high wearing comfort degree with the target human eye can be obtained through design. In addition, the effect of the adjustment can be conveniently predicted by adjusting the vertical distance of the second reference point from the X axis during fitting, for example, when the fitting result is that the lens is too tight, the vertical distance of the second reference point from the X axis can be adjusted to be smaller so that the adjusted cornea contact lens 1 is adapted to the target human eye.

In some examples, in step S200, the raw curve may be obtained based on vision that requires correction. In particular, the diopter may be obtained according to the result of the inspection of the human eye. In this disclosure, the raw curve may also be referred to as an optical curve.

In some examples, in step S300, the first reference point may be an intersection point P10 of the peripheral arc region 22 and the edge warp arc region 23 (see fig. 4). In some examples, in step S300, the second reference point may be a boundary point P20 of the inner surface 20 (see fig. 4).

In some examples, the intersection of the peripheral arc 22 and the limbal arc 23 may be in contact with the anterior surface of the cornea 2 when worn. In this case, the position of the first reference point can be conveniently determined based on the corneal topographer.

In some examples, the boundary point of the peripheral arc region 22 and the edgewise arc region 23 and the boundary point of the inner surface 20 may be a first predetermined distance apart in the X-axis direction and a second predetermined distance apart in the Z-axis direction. In other words, the first reference point and the second reference point may be spaced apart from each other by a first predetermined distance in the X-axis direction and a second predetermined distance in the Z-axis direction. Preferably, the first predetermined distance may be 0.3mm to 3mm, and the second predetermined distance may be 0.03mm to 0.30mm. In this case, the raised height of the raised edge zone 23 is set within this range, which is advantageous for improving the comfort of wearing while satisfying the tear exchange requirement.

In some examples, in step S300, the plurality of reference points further includes 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. In this case, the preset curve can be further adapted to the cornea 2, improving the comfort of wearing.

In some examples, in step S300, the number of the plurality of reference points may be not less than 2. For example, the number of the plurality of reference points may be 2, 3, 4, 5, 6, 7, 8, 9, 10, or more. In this case, the greater the number of reference points selected, the greater the degree of matching of the preset curve obtained by fitting to the cornea 2.

In some examples, as described above, in step S400, the fitting of the contact lens 1 in the initial state may be performed, and the vertical distance of the second reference point from the X axis may be adjusted based on the fitting result. Here, the contact lens 1 in the initial state refers to the contact lens 1 in which the form of the inner surface 20 satisfies the original curve. In this case, the edge warp arc region 23 can be adapted to the shape of the cornea 2 by adjusting the vertical distance of the second reference point from the X axis based on the fitting result.

In some examples, in step S400, the distance between the adjusted second reference point and the second reference point before adjustment may be any value in the range of-0.5 mm to 0.5mm, such as-0.2 mm, 0.3mm, and so on, in the X-axis direction. Wherein "0.5mm" means that the second reference point before adjustment is adjusted by 0.5mm in a direction away from the X-axis; "-0.5mm" means that the second reference point before adjustment is adjusted by 0.5mm in the direction of the X-axis. Advantageously, by setting the adjustment range of the second reference point to-0.5 mm to 0.5mm, the adjusted tilted rim area 23 matches with the cornea 2, so as to satisfy the requirement of tear exchange and achieve good wearing effect (e.g., reduce the undesirable foreign body sensation caused by excessive tilting during wearing).

In some examples, in step S400, the fitting result may include a distribution of fluorescence bands under slit-lamp fluorescence detection. In this case, the fitting state of the contact lens 1 in the above-described form to the target human eye can be obtained from the distribution of the fluorescence bands obtained at the time of trial wearing. For example, whether the corneal contact lens 1 in the shape is too loose or too tight relative to the target human eye can be judged according to the thickness of the fluorescence band, and then the vertical distance from the second reference point to the X axis is adjusted based on the fitting condition so as to enable the lens to be better fitted to the target human eye.

It should be noted that, although the distribution of the fluorescence bands is used as a reference for adjusting the plurality of reference points in the example of the present disclosure, the adjustment may be performed in combination with other parameters in many cases. For example, in some examples, the fitting results may also include experience of the fitting person in step 400. In this case, the positions of the plurality of reference points can be adjusted today in combination with the reference fluorescence band distribution and the experience of the try-on person, thereby enabling the corneal contact lens 1 to be further adapted to the target human eye.

In some examples, in step S400, when the width of the fluorescent stripe is greater than 1mm in the X-axis direction, the first reference point and/or the second reference point may be adjusted to be farther from the X-axis. In this case, the reason why the width of the fluorescence band is greater than 1mm includes that the lens in this form is looser (i.e. the fitting degree of the edge warping arc zone 23 and the cornea 2 is smaller) relative to the target human eye, and at this time, by adjusting the first reference point and/or the second reference point to be farther from the X axis, the fitting degree of the edge warping arc zone 23 and the cornea 2 can be increased, so that the adjusted cornea contact lens 1 is adapted to the target human eye, and the wearing comfort can be improved.

In some examples, in step S400, when the width of the fluorescence band is less than 0.5mm in the X-axis direction, the first reference point and/or the second reference point may be adjusted to be closer to the X-axis. In this case, the reason why the width of the fluorescence band is less than 0.5mm includes that the lens in this form is relatively tight with respect to the target human eye (i.e., the fit between the edge tilted arc area 23 and the cornea 2 is too high, which may cause excessive compression on the cornea 2), and at this time, by adjusting the first reference point and/or the second reference point to be closer to the X axis, the compression of the edge tilted 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 favorable for tear exchange, and the wearing comfort can be improved.

In some examples, in step S400, when the width of the fluorescent stripe is greater than 1mm or less than 0.5mm in the X-axis direction, the first reference point and the second reference point may be adjusted at the same time.

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

Fig. 5 is a schematic diagram illustrating adjustment of a reference point to which examples of the present disclosure relate. In fig. 5, some lines are omitted for clarity of illustrating how the reference points are adjusted.

In some examples, as described above, the second reference point may be adjusted to be closer to the X-axis when the width of the fluorescence band is less than 0.5mm. For example, referring to fig. 5, L0 is a raw curve, the second reference point P20 on the raw curve L0 may be moved to a position P21 shown in the figure toward the X axis, so as to obtain the coordinates of the adjusted second reference point P21, and then the preset curve obtained by fitting is approximately in the shape shown by L1.

In some examples, as described above, the second reference point may be adjusted to be farther from the X-axis when the width of the fluorescence band is greater than 1 mm. For example, referring to fig. 5, the second reference point P20 on the original curve L0 may be moved to a position P22 shown in the figure in a direction away from the X axis, so as to obtain the coordinates of the adjusted second reference point P22, and then the preset curve obtained by fitting is approximately in the shape shown by L2.

In some examples, referring to fig. 5, P11 is a middle point (i.e., a third reference point) of the preset curve L2 along the X-axis direction, the third reference point P11 on the preset curve L2 may be moved to a position P13 shown in the figure toward the X-axis direction without adjusting the second reference point P21, so as to obtain a coordinate of the adjusted third reference point P13, and the preset curve obtained by fitting the coordinate is substantially in a shape shown in L3.

In some examples, in step S400, the vertical distance of the first reference point from the Z-axis may also be adjusted based on the distribution of the fluorescence bands under slit-lamp fluorescence detection. In this case, whether the size of the contact lens 1 in the shape is adapted to the target human eye can be judged according to the distribution of the fluorescence bands, and then the vertical distance between the first reference point and the Z axis is adjusted based on the adaptation condition so that the contact lens 1 is better adapted to the target human eye.

In some examples, in step S400, when the width of the fluorescent stripe is greater than 1mm in the X-axis direction, the first reference point may be adjusted to be farther from the Z-axis. In this case, the reason that the width of the fluorescence band is greater than 1mm includes that the edge tilting arc zone 23 of the corneal contact lens 1 in this form is too wide in the X-axis direction relative to the target eye, and at this time, the width of the edge tilting arc zone 23 can be reduced by adjusting the first reference point to be farther from the Z-axis, so that the fitting degree of the edge tilting arc zone 23 and the cornea 2 can be increased, and thus the adjusted corneal contact lens 1 is adapted to the target eye, and the wearing comfort can be improved.

In some examples, in step S400, when the width of the fluorescence band is less than 0.5mm in the X-axis direction, the first reference point is adjusted to be closer to the Z-axis. In this case, the reason why the width of the fluorescence band is less than 0.5mm includes that the edge warping zone 23 of the contact lens 1 in this form is too narrow in the X axis direction with respect to the target eye, and at this time, the width of the edge warping zone 23 can be increased by adjusting the first reference point closer to the Z axis, which helps to uniformly disperse the pressure of the contact lens 1 on the cornea 2 and to exchange tears, thereby improving the safety and comfort of the contact lens 1.

In some examples, in step S400, the degree of dispersion of the plurality of reference points may also be adjusted based on the distribution of the fluorescence bands under the slit-lamp fluorescence detection. In this case, by having a plurality of reference points densely distributed in certain specific areas, the preset curve in this area can be further adjusted, so that the edge warp zone 23 is better adapted to the cornea 2; and the plurality of reference points are distributed sparsely in certain specific areas, so that the required calculation amount can be reduced, and the lens matching efficiency is improved.

In some examples, in step S400, when the width of the fluorescence band is greater than 1mm in the X-axis direction, the plurality of reference points may be gradually dense in the inside-out direction. The reason why the width of the fluorescence band is greater than 1mm includes that the corneal contact lens 1 in this form is too loose or too wide in size with respect to the cornea 2, and in this case, the degree of matching between the boundary point of the inner surface 20 and the cornea 2 is lower than that at the boundary point of the edge tilted arc region 23 and the peripheral arc region 22, and at this time, by arranging a plurality of reference points so as to be gradually dense in the direction from inside to outside, it is possible to more finely adjust the portion of the edge tilted arc region 23 that is relatively close to the boundary point of the inner surface 20, and thus it is possible to better fit the edge tilted arc region 23 to the cornea 2 as a whole.

In some examples, in step S400, when the width of the fluorescence band is less than 0.5mm in the X-axis direction, the plurality of reference points may be gradually thinned out along the inside-out direction. The reason why the width of the fluorescence band is less than 0.5mm includes that the corneal contact lens 1 in this form is too tight or too narrow in size relative to the cornea 2, and in this case, the degree of matching between the boundary point of the edge tilted arc region 23 and the peripheral arc region 22 and the cornea 2 is lower than that at the boundary point of the inner surface 20, and at this time, by arranging a plurality of reference points to be gradually sparse along the direction from inside to outside, it is possible to finely adjust the portion of the edge tilted arc region 23 that is relatively close to the boundary point of the edge tilted arc region 23 and the peripheral arc region 22, so that the edge tilted arc region 23 can be better fitted to the cornea 2 as a whole.

In some examples, the second reference point in different quadrants is at a different vertical distance from the X-axis as adjusted. And after adjustment, the vertical distance from the first reference point in different quadrants to the Z axis is different. In this case, since the cornea 2 of the human eye generally has different shapes in different quadrants, the vertical distance from the first reference point to the Z axis and/or the vertical distance from the second reference point to the X axis in different quadrants can be adjusted to enable the edge tilting arc 23 of each quadrant to better match the shape of the cornea 2 of each quadrant, that is, to better contact and fit with the cornea 2 of each quadrant, so that the pressure on the cornea 2 caused by the corneal contact lens 1 can be uniformly dispersed, tear exchange can be facilitated, and the safety and comfort of the corneal contact lens 1 can be improved. That is, the limbal arc region 23 may be quadrant segmented to match the morphology of the cornea 2 in different quadrants.

Fig. 6A is a schematic diagram illustrating an inner surface 20 according to an example of the present disclosure. Fig. 6B is a schematic diagram illustrating a zoning design for the side warp arc zone 23 in accordance with an example of the present disclosure. Fig. 6C is a schematic diagram illustrating a partitioned designed edge warp arc 23 on the XZ plane according to an example of the present disclosure. In fig. 6B and 6C, Q1 schematically represents a first quadrant, and Q2 schematically represents a second quadrant.

In some examples, as described above, the inner surface 20 may include the optical arc region 21, the peripheral arc region 22, and the edge warping region 23 surrounding the periphery of the peripheral arc region 22 (see fig. 6A).

In some examples, the edgewise arc 23 may be divided into quadrants for quadrant design. For example, in the example shown in fig. 6B and 6C, the edge warping zone 23 may be divided into 2 quadrants (i.e., a first quadrant Q1 and a second quadrant Q2) for quadrant division design, the first quadrant Q1 may be a quadrant relatively close to the nasal side, the second quadrant Q2 may be a quadrant relatively close to the temporal side, and the edge warping zones 23a and 23B of the first and second quadrants Q1 and Q2 may have different shapes to match the shape of the cornea 2 in the corresponding quadrants. Thus, the side warp arc regions 23 of the respective quadrants can be brought into contact with the cornea 2 of the respective quadrants better, thereby improving wearing comfort.

In other examples, the edge warp arc zone 23 may be divided into 3, 4, 5, 6, 8, 16, or more quadrants for quadrant division design. In this case, the more quadrants divided, the higher the degree of matching of the designed contact lens 1 to the morphology of the cornea 2 of the target human eye. In some examples, the edge warp arc area 23 may be divided into 4 quadrants for partition design. For example, the limbal arc region 23 may be divided into four quadrants, nasal, temporal, superior and inferior. In this case, both the matching accuracy and the fitting efficiency can be considered.

Additionally, in some examples, the edge warp zone 23 may also not have quadrant specificity. For example, the edgewise arc 23 may have rotational symmetry.

In some examples, other arc zones of the inner surface 20 may also be divided into quadrants for quadrant division design. This allows the inner surface 20 of each quadrant to be adapted to the shape of the cornea 2 of each quadrant.

In some examples, in step S400, the vertical distance of each reference point from the Z-axis may be adjusted in steps of 0.05mm-0.5mm, for example, 0.1mm, 0.15 mm; in step S400, the vertical distance of each reference point from the X-axis may be adjusted in steps of 0.005mm to 0.05mm, for example, 0.01mm, 0.015 mm. In some examples, in the case that the width of the fluorescent strip is significantly greater than 1mm (e.g., 2mm, 3 mm), or significantly less than 0.5mm (e.g., 0.1mm, 0.2 mm), the position of each reference point may also be adjusted in steps greater than 0.5mm, thereby facilitating improved fitting efficiency.

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

In some examples, the second reference point on the original curve may be moved toward the direction close to the X-axis by a preset distance based on the original curve designed by the cornea topographer of the target human eye, and fitting is performed after fitting to obtain an adjusted preset curve, and then fitting is performed. Wherein, the preset distance can be obtained according to clinical data statistics. In this case, the fitting degree of the adjusted contact lens 1 to most human eyes is high, the contact lens 1 in this form is used as an initial fitting lens to be fitted during fitting, and the positions of the plurality of reference points are adjusted based on the fitting result, so that the number of times of adjusting the positions of the reference points can be reduced, and the fitting efficiency can be improved.

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

In some examples, the contact lens 1 includes an optical zone, a peripheral zone, and a rim-warp zone surrounding the periphery of the peripheral zone, which are sequentially formed from inside to 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 zone is an edge warp arc zone 23.

In some examples, the central thickness of the contact lens 1 may be selected from any value between 0.10mm and 1.00mm. In this case, the weight of the contact lens 1 can be reduced while suppressing the occurrence of undesired deformation of the contact lens 1, thereby improving 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 diopter is 0D- +10D, the thickness is 0.20 mm-0.80 mm; the thickness is 0.40mm to 1.00mm when the diopter is +10D to + 25D.

In some examples, the thickness of the edge warp zone of the contact lens 1 may gradually decrease from inside to outside. In this case, it can be advantageous to improve wearing comfort.

In some examples, the outer surface 10 of the contact lens 1 may be designed to have a continuously curved shape based on sagittal height. This can contribute to improvement in wearing comfort.

In some examples, the contact lens 1 may have a prescription zone and an over-the-counter zone. When the contact lens 1 is worn, light entering the human eye through the prescription zone can be focused on the retina, and light entering the human eye through the non-prescription zone can be focused in front of the retina. Therefore, the myopia can be controlled or delayed to deepen, and the requirement of vision correction can be met.

In some examples, the contact lens 1 can be formed as a multifocal contact lens 1 via an out-of-focus design (i.e., the contact lens 1 has different diopters in different functional regions via an out-of-focus design). Specifically, the optical zone may be set as a prescription zone, and the peripheral zone may be set as an over-the-prescription zone. The prescription zone has a refractive power for correcting vision, and the non-prescription zone has a refractive power different from that of the prescription zone.

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

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

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

In another aspect, the present disclosure relates to a contact lens 1, which is a contact lens 1 prepared by the above design method. Thus, a contact lens having a high fitting degree with the eye of the subject person and a high wearing comfort can be obtained. The respective structures and the related settings of the contact lens 1 are explained in the above design method, and are not described in detail here.

It should be understood that the above other parameters of the contact lens are merely illustrative of a contact lens designed according to the present invention, and that contact lenses formed by the design of the present invention may have other configurations. The design method of the invention provides a method for adjusting the edge warping arc area, and the edge warping arc area which is moderate in elastic band with the cornea can be obtained in other areas of the corneal contact lens with any shape according to the design method disclosed by the invention, and the corneal contact lens with the edge warping arc area. As mentioned above, the raised areas can provide a proper space for tear exchange and make the contact lens not easy to fall off.

According to the present disclosure, a contact lens 1 with high wearing comfort and a method for designing the same can be provided.

While the present disclosure has been described in detail above with reference to the drawings and the embodiments, it should be understood that the above description does not limit the present disclosure in any way. Variations and changes may be made as necessary by those skilled in the art without departing from the true spirit and scope of the disclosure, which fall within the scope of the disclosure.

Claims (14)

1. A design method of a corneal contact lens is characterized in that the corneal contact lens is provided with an inner surface which faces towards a cornea when being worn and is matched with the front surface of the cornea, and an outer surface which is opposite to the inner surface, the inner surface comprises an optical arc area, a peripheral arc area and a side warping arc area which surrounds the periphery of the peripheral arc area, the optical arc area, the peripheral arc area and the side warping arc area are sequentially formed from inside to outside,

the design method comprises the following steps:

setting an original curve of an inner surface of a corneal contact lens for correcting refractive error based on a corneal topographer in an XZ plane constructed with a sagittal direction of the corneal contact lens as a Z-axis direction, a width direction of the corneal contact lens as an X-axis direction, and a vertex of the inner surface as an origin,

selecting a plurality of reference points with the number not less than 2 on the original curve, wherein the plurality of reference points at least comprise a first reference point and a second reference point, the first reference point is a boundary point of the peripheral arc area and the edge tilted arc area, the second reference point is a boundary point of the inner surface,

try on the cornea contact lens in the initial state, adjust the vertical distance between the second reference point and the X axis based on the try-on result,

designing the edge warping arc area to meet a preset curve, wherein the preset curve meets the following requirements:

wherein X is the perpendicular distance of a point on the inner surface from the Z axis, Z (X) is the perpendicular distance of a point on the inner surface from the X axis, A _i Is a polynomial coefficient, n is an integer of 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 derivative of the preset curve is equal to the first derivative of the original curve.

2. The design method of claim 1, wherein the fitting result comprises a distribution of a fluorescence band under slit-lamp fluorescence detection.

3. The design method according to claim 2, wherein the first reference point and/or the second reference point is adjusted to be farther from the X-axis when the width of the fluorescent stripe is greater than 1mm in the X-axis direction; and/or

And in the X-axis direction, when the width of the fluorescent strip is less than 0.5mm, the first reference point and/or the second reference point are/is adjusted to be closer to the X axis.

4. A design method according to any one of claims 1 to 3, wherein the vertical distance of the second reference point from the X-axis in different quadrants is adjusted to be different.

5. The design method of claim 2, wherein the vertical distance of the first reference point from the Z-axis is further adjusted based on the distribution of fluorescence bands under slit-lamp fluorescence detection.

6. The design method of claim 5, wherein the first reference point is adjusted to be farther from the Z axis when the width of the fluorescent stripe is greater than 1mm in the X axis direction; and/or

And in the X-axis direction, when the width of the fluorescent strip is less than 0.5mm, the first reference point is adjusted to be closer to the Z axis.

7. The design method of claim 5 or 6, wherein the vertical distance of the first reference point from the Z axis in different quadrants is adjusted to be different.

8. The design method of claim 2, wherein the degree of dispersion of the plurality of reference points is adjusted based on a distribution of fluorescence bands under slit-lamp fluorescence detection.

9. The design method of claim 8, wherein the plurality of reference points are gradually dense in an inside-out direction when the width of the fluorescence band is greater than 1mm in the X-axis direction; and/or

In the direction of the X axis, when the width of the fluorescent strip is less than 0.5mm, the reference points are gradually sparse along the direction from inside to outside.

10. The design method according to claim 1, wherein a distance between the adjusted second reference point and the second reference point before adjustment in the X-axis direction is taken from an arbitrary value in a range of-0.5 mm to 0.5mm.

11. The design method of claim 1, wherein the plurality of reference points further includes a third reference point, the third reference point being a midpoint of the original curve along an X-axis direction or a midpoint along a Z-axis direction.

12. The design method of claim 1, wherein the interface point contacts the anterior surface of the cornea when worn.

13. The design method of claim 1, wherein a boundary point of the inner surface is spaced from the intersection point 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 0.3mm to 3mm and the second predetermined distance is 0.03mm to 0.3mm.

14. A contact lens produced by the designing method according to any one of claims 1 to 13.

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