Contact lenses

Abstract

To provide a novel contact lens having a reduced thickness difference to ensure both wearing comfort and good rotational positioning performance, so as to compensate for inadequacies of existing techniques.SOLUTION: A contact lens provided herein includes a toric lens body. The toric lens body has radii extending outward from the center in a radial direction. The radii define cross-sections along a thickness direction of the toric lens body. Area "A" of the cross section is represented by a formula (I): A=P-f(θ), where θ represents an azimuth angle and satisfies 0°≤θ≤360, f(θ) represents a polynomial, and P satisfies 0.5≤P≤7.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to contact lenses, and more particularly to astigmatic contact lenses. [Background technology]

[0002] For contact lenses with astigmatic power, the positioning of the contact lens is very important. If the contact lens is not properly positioned, it will tend to rotate when worn, and the ideal correction effect will not be achieved.

[0003] According to the positioning method, contact lenses currently on the market can be roughly divided into two types: ballast design and top and bottom thinning design. These two structural design methods achieve the positioning effect by changing the thickness of the contact lens.

[0004] Ballast-design contact lenses utilize the force of gravity to position the heavy end of the contact lens downwards when worn, while top-bottom-thinning contact lenses achieve positioning by allowing both thin ends of the contact lens to rotate to a position where they overlap the eyelids at the moment of blinking.

[0005] Contact lenses are divided into a central optical area and an annular area around the periphery. The thickness of the optical area varies depending on the astigmatism power; as the astigmatism power increases, the thickness of the optical area also increases. The thickness of the annular area is designed based on different positioning mechanisms (e.g., ballast design or top and bottom thinning design). The annular area around the periphery is the part that mainly achieves the positioning effect.

[0006] In order to achieve the above-mentioned positioning effect, the design process usually divides the peripheral annular area into several sub-areas and designs the thickness of each sub-area separately, but this type of thickness design process only considers the positioning performance of the contact lens, and does not consider the power correction issue of the optical area at the same time.

[0007] Therefore, there is a large thickness difference at the boundary between the peripheral annular area and the central optical area, which can cause a foreign body sensation to the user and lead to an uncomfortable wearing experience, even with the adjustment of curvature.

[0008] Specifically, for existing contact lenses, when the astigmatism power is 0°, the difference in lens thickness ranges from 15% to 200%. For high astigmatism power (e.g., 700°), the difference in lens thickness ranges from 20% to 110%.

[0009] Therefore, how to reduce the difference in thickness of contact lenses through improved structural design has become one of the key issues this product aims to solve. Summary of the Invention [Problem to be solved by the invention]

[0010] The technical problem that the present invention aims to solve is to provide a new contact lens that compensates for the shortcomings of existing technology, which reduces the difference in lens thickness and achieves both comfort when worn and good rotational positioning performance. [Means for solving the problem]

[0011] To solve the above-mentioned technical problems, one technical solution adopted by the present invention is to provide a contact lens. The contact lens includes a toric lens body. The toric lens body has a radius extending radially outward from the center. The toric lens body is configured such that the area A of a cross section in the thickness direction along the radius satisfies the formula (I): A=Pf(θ), where θ is the azimuthal angle, 0°≦θ≦360°, and f(θ) is a polynomial, 0.5≦P≦7.

[0012] In some embodiments, the f(θ) is (aθ 4 +bθ 3 +cθ 2 +dθ), where θ is the azimuth angle, 0°≦θ≦360°, -10 -8 ≦a≦-10 -10 , 10 -8 ≦b≦10 -5 , -10 -1 ≦c≦-10 -5 , 10 -5 ≦d≦10 -1 is.

[0013] In some embodiments, −10 -8 ≦a≦-10 -9 , 10 -6 ≦b≦10 -5 , -10 -1 ≦c≦-10 -4 , 10 -4 ≦d≦10 -1 is.

[0014] In some embodiments, f(θ) is a trigonometric polynomial, and f(θ) is expressed as f(θ)=[k1 sin(θ / 2)+k2 cos 2 (θ / 2)], where θ is the azimuth angle, 0°≦θ≦360°, -0.2≦k1≦0.5, 0≦k2≦6, and k2 <P。

[0015] In some embodiments, the maximum radial thickness variation of the toric lens body is less than 100%.

[0016] In some embodiments, the maximum radial thickness change of the toric lens body is less than 55%.

[0017] In some embodiments, the ratio of the area of ​​the toric lens body at an azimuth angle of 180° to the area of ​​the toric lens body at an azimuth angle of 0° is between 1.0 and 7.5.

[0018] In some embodiments, the ratio of the area of ​​the cross section of the toric lens body at an azimuth angle of 90° to the area of ​​the cross section of the toric lens body at an azimuth angle of 0° is between 1.0 and 4.5.

[0019] In some embodiments, the ratio of the area of ​​the cross section of the toric lens body at an azimuth angle of 180° to the area of ​​the cross section of the toric lens body at an azimuth angle of 90° is between 1.0 and 1.8.

[0020] In some embodiments, the arcuate cross-section formed by the radial cross-section of the toric lens body includes an optic area cross-section and an annular area cross-section. [Effects of the Invention]

[0021] One beneficial effect of the present invention is that the contact lens provided by the present invention achieves both comfortable wearing and good rotational positioning performance through the technical solution that "the cross-sectional area A satisfies formula (I) of A=Pf(θ)" and "θ is the azimuth angle, 0°≦θ≦360°, 0.5≦P≦7, and f(θ) is a polynomial."

[0022] In order to better understand the features and technical contents of the present invention, please refer to the following detailed description of the present invention and the accompanying drawings, which are provided for reference and explanation only and are not intended to limit the scope of the present invention. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a three-dimensional schematic diagram of a contact lens of the present invention. [Figure 2] FIG. 2 is a schematic three-dimensional view of one arc-shaped cross section of the contact lens in FIG. 1. [Figure 3] FIG. 3 is an enlarged schematic view of the arc-shaped cross section in FIG. 2. [Figure 4] 1 is a schematic top view of a contact lens of the present invention. [Figure 5] FIG. 4 is a diagram showing the relationship between the area of ​​an arc-shaped cross section and the azimuth angle in the first embodiment. [Figure 6] FIG. 2 is a schematic diagram of a radial cross section at an azimuth angle of 0° in the first embodiment. [Figure 7] FIG. 2 is a schematic diagram of a radial cross section at an azimuth angle of 90° in the first embodiment. [Figure 8] FIG. 2 is a schematic diagram of a radial cross section at an azimuth angle of 180° in the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] The following specific embodiments will be used to describe the "contact lenses" disclosed in the present invention. Those skilled in the art will understand the advantages and benefits of the present invention from the disclosure of this specification. The present invention can be implemented or applied in other different embodiments. Each detail in this specification can also be modified and changed in various ways without departing from the spirit of the present invention based on various aspects or applications. Furthermore, the drawings of the present invention are for simple and schematic illustration only and do not represent actual dimensions. The following embodiments will further explain the technical matters related to the present invention, but the disclosed contents should not be construed as limiting the present invention.

[0025] To overcome the problems of the existing technology, the present invention provides a contact lens that combines good positioning performance and a low thickness difference. Unlike the conventional design method that only considers the influence of the thickness of the annular area on the positioning effect, the present invention designs the contact lens based on the area formed by the radial cross section. The area formed by the radial cross section simultaneously covers the annular area and the optical area of ​​the contact lens, so that the positioning performance of the annular area of ​​the contact lens and the thickness difference at the intersection between the annular area and the optical area can be simultaneously considered during the design process.

[0026] See Figure 1. The contact lens of the present invention includes a toric lens body 1. For ease of explanation, the toric lens body 1 is divided into an optic area 10 and an annular area 20. In reality, however, the optic area 10 and the annular area 20 are integrally molded and have no clear boundary therebetween.

[0027] Specifically, the optical area 10 is located at the center of the toric lens body 1, and the area of ​​the optical area 10 corresponds to the size of the pupil. The annular area 20 surrounds the optical area 10, and the optical area 10 and the annular area 20 are concentrically arranged.

[0028] See Figure 2. The outer surface S1 of the toric lens body 1 has a center O, and the toric lens body 1 has a radius extending radially outward from the center O. Figure 2 shows a cross section of the toric lens body 1 in the thickness direction along the radius (i.e., the z-axis direction in Figure 2).

[0029] Specifically, this cross section is an arc-shaped cross section, which is an area defined by a first curve C1, a second curve C2, and a central cross section line H. The radius intersects with the outer surface S1 of the toric lens body 1 at the first curve C1, and with the inner surface S2 of the toric lens body 1 at the second curve C2, and extends from the center O along the z-axis to form the central cross section line H.

[0030] Please refer to Figure 3. Figure 3 is an enlarged schematic diagram of the arc-shaped cross section in Figure 2. The arc-shaped cross section includes an optical area 10 and an annular area 20. Therefore, the arc-shaped cross section includes an optical area cross section A1 and an annular area cross section A2. Specifically, the radius in the thickness direction (z-axis direction) forms the optical area cross section A1 at the cross section of the optical area 10, and forms the annular area cross section A2 at the cross section of the annular area 20.

[0031] As the azimuth angle θ changes, the toric lens body 1 has different radii. In the present invention, the area A of the arc-shaped cross section under different azimuth angles θ follows the formula (I) of A=Pf(θ). Specifically, the area A under different azimuth angles θ approximately describes a parabolic curve.

[0032] In formula (I), θ is the azimuth angle, and f(θ) is a polynomial. 0°≦θ≦360°, 0.5≦P≦7. For further explanation, the area A of the arc-shaped cross section in formula (I) is the sum of the areas of the optical area cross section A1 and the annular area cross section A2.

[0033] In one embodiment, f(θ) is (aθ 4 +bθ 3 +cθ 2 +dθ). Therefore, the area A of the arc section is expressed as A=P-(aθ 4 +bθ 3 +cθ 2 +dθ) according to equation (II).

[0034] In formula (II), θ is the azimuth angle, and 0°≦θ≦360°, 0°≦θ≦360°, 0.5≦P≦7, −10 -8 ≦a≦-10 -10 , 10 -8 ≦b≦10 -5 , -10 -1 ≦c≦-10 -5 , 10 -5≦ d≦10 -1 is.

[0035] By adjusting the parameters "P", "a", "b", "c" and "d", different formulas (II) can be obtained, which can be used to obtain the area of ​​the arc-shaped cross section under different azimuth angles, and based on this, the area of ​​the annular area cross section A2 can be designed.

[0036] In a more preferred embodiment, in formula (II), -10 -8 ≦a≦-10 -9 , 10 -6 ≦b≦10 -5 , -10 -1 ≦c≦-10 -4 , 10 -4 ≦d≦10 -1 is.

[0037] Furthermore, the polynomial for f(θ) can be a trigonometric polynomial. Experiments have shown that designing the cross-sectional area of ​​the toric lens body based on a trigonometric polynomial can provide a contact lens that is both comfortable to wear and has good rotational positioning performance.

[0038] In one embodiment, f(θ) is [k1 sin(θ / 2) + k2 cos 2 (θ / 2)]. Therefore, the area A of the arc section under different azimuth angles θ is expressed as A=P-[k1sin(θ / 2)+k2cos 2 (θ / 2)] according to equation (III).

[0039] In formula (III), θ is the azimuth angle, and 0°≦θ≦360°, 0.5≦P≦7, −0.2≦k1≦0.5, 0≦k2≦6, and k2 <Pである。

[0040] By adjusting the parameters "P", "k1", and "k2", different formulas (III) can be obtained, and the area of ​​the arc-shaped cross section under different azimuth angles can be obtained using formula (III), and the area of ​​the annular area cross section A2 can be designed based on this. The specific design method will be described in Example 1.

[0041] In a more preferred embodiment, in formula (III), 0.5≦P≦7.

[0042] In formula (III), the maximum area of ​​the arcuate cross section within the toric lens body 1 is controlled by "P-k1," and the minimum area of ​​the arcuate cross section within the toric lens body 1 is controlled by "P-k2." The larger "k1" is, the greater the variation in the area of ​​the arcuate cross section with changes in azimuth angle. "k2" fine-tunes the area difference between adjacent arcuate cross sections, making the overall appearance of the toric lens body 1 smoother and flatter.

[0043] From equations (II) and (III), it can be seen that when the azimuth angle θ is 0°, the arc-shaped cross section has the smallest area, and when the azimuth angle θ is 180°, the arc-shaped cross section has the largest area. The areas are the same when the azimuth angle θ is 90° and 270°. This shows that the toric lens body 1 of the present invention is a ballast-type contact lens.

[0044] 3, the optical area cross section A1 is integrated in the direction of change of the azimuth angle to obtain the optical area 10 of the toric lens body 1. Therefore, after obtaining the patient's optometry data, the area of ​​the optical area cross section A1 under different azimuth angles θ is first designed based on the optometry data, and then the structure of the optical area 10 is obtained by integrating the optical area cross section A1.

[0045] Similarly, the annular area 20 of the toric lens body 1 can be obtained by integrating the annular area cross section A2 in the direction of change in azimuth angle. The difference is that before designing the area of ​​the annular area cross section A2, the area of ​​the arc-shaped cross section under each azimuth angle θ must first be calculated using formula (III). After subtracting the area of ​​the optical area cross section A1 from the area, the area of ​​the annular area cross section A2 can be obtained. By integrating the annular area cross section A2, the structure of the annular area 20 can be obtained.

[0046] From the above, the present invention designs the structure of the toric lens body 1 by adjusting the area of ​​the arc-shaped cross section, while taking into consideration the influence of the optic area 10 and the annular area 20 on the overall structure of the toric lens body 1. As a result, the thickness difference at the intersection between the optic area 10 and the annular area 20 can be reduced.

[0047] Please refer to Figure 4. Figure 4 is a schematic top view of the toric lens body in Figure 2. For ease of explanation, an azimuth angle θ of 0° is defined as the upper part of the toric lens body, and an azimuth angle θ of 180° is defined as the lower part of the toric lens body. Specifically, the azimuth angle is the azimuth angle measured clockwise when observing the toric lens body from above, with the center O of the toric lens body as the origin and the direction directly above the center (i.e., the 12 o'clock direction) as 0°.

[0048] Generally, thickness differences are likely to occur at the points B1 and B2 where the optical area 10 and the annular area 20 intersect. In ballast contact lenses, the toric lens body 1 tends to be thinner at the top and thicker at the bottom.

[0049] Therefore, when the astigmatic power is high, the lens thickness of the optical area 10 is thick, and a thickness difference easily occurs at the upper part of the toric lens body 1 (point B1 where the azimuth angle θ intersects with 0°). When the astigmatic power is low, the lens thickness of the optical area 10 is thin, and a thickness difference easily occurs at the lower part of the toric lens body 1 (point B2 where the azimuth angle θ intersects with 180°). [Example 1]

[0050] In Example 1, the parameters P=2.5, k1=0.5, and k2=2 are substituted into the formula (III) to obtain 2.5-[0.5 sin(θ / 2)+2 cos 2 (θ / 2)] was obtained.

[0051] The contact lens design process begins by dividing the toric lens body 1 into a concentrically arranged optical area 10 and an annular area 20 (see FIG. 1). The toric lens body 1 has radii extending from a center O along different azimuthal angles θ, and these radii form an arc-shaped cross section through a cross section in the thickness direction. The arc-shaped cross section was composed of an optical area cross section A1 and an annular area cross section A2.

[0052] In Example 1, the area of ​​the optical area cross section A1 is designed based on optometry data with an astigmatism power of 0°. Through calculation of formula (III), the area (design data) of the arc-shaped cross section under different azimuth angles can be obtained. The obtained area is plotted against the azimuth angle as shown in Figure 5. From Figure 5, it can be seen that the toric lens body 1 of the first embodiment is a ballast-type contact lens.

[0053] The area of ​​the annular area cross section A2 is designed by combining the optometry data and the design data. Since the arc-shaped cross section is composed of the optical area cross section A1 and the annular area cross section A2, the area of ​​the annular area cross section A2 is obtained by subtracting the area of ​​the optical area cross section A1 from the area obtained by formula (III).

[0054] After the optical area cross section A1 and the annular area cross section A2 are designed at each azimuth angle θ, the optical area cross section A1 and the annular area cross section A2 are integrated to form an arc-shaped cross section, and then integrated along the direction of change in the azimuth angle to obtain the toric lens body 1 of Example 1.

[0055] It should be noted that the above description is merely an explanation of one method for designing the toric lens body 1 and is not intended to limit the present invention.

[0056] Please refer to Figures 6 to 8. Figures 6 to 8 are schematic diagrams of the arc-shaped cross-section of the toric lens body 1 when the azimuth angle is 0°, 90°, and 180°, respectively. As shown in Figures 6 to 8, as the azimuth angle θ increases, the area of ​​the optical area cross-section A1 increases slightly, and the area of ​​the annular area cross-section A2 increases more significantly. However, in the overall structure, the toric lens body 1 can still maintain a smooth and flat appearance.

[0057] See Table 1, which lists the relative values ​​of the area and normalized area of ​​the arc cross section at azimuth angles of 0°, 90°, and 180°.

[0058] [Table 1]

[0059] At the intersection point B1 (azimuth angle θ is 0°) and the intersection point B2 (azimuth angle θ is 180°), the thicknesses of the edge of the optical area 10 and the edge of the annular area 20 of the toric lens body 1 are measured, and the thickness difference and the thickness difference ratio are calculated. Here, the thickness difference ratio is calculated as the difference in thickness between the optical area 10 and the annular area 20 at the intersection points B1 and B2, expressed as a percentage of the thickness of the edge of the optical area 10. The specific thicknesses, thickness differences, and thickness difference ratios of the intersection points B1 and B2 in Example 1 are listed in Table 2.

[0060] [Table 2]

[0061] Based on the results in Table 2, the toric lens body 1 of the present invention has a low thickness change rate at the intersection points B1 and B2 of the optical area 10 and the annular area 20, which is less than 150%, which is lower than the thickness change rate of lenses in the existing technology (15% to 200%). Therefore, the present invention simultaneously takes into account the area of ​​the optical area 10 and the area of ​​the annular area 20, allowing the toric lens body 1 to have good positioning effect and wearing comfort.

[0062] Preferably, the thickness change rate at the intersection points B1, B2 of the optical area 10 and the annular area 20 is less than 150%. Even more preferably, the thickness change rate at the intersection points B1, B2 of the optical area 10 and the annular area 20 is less than 100%. Even more preferably, the thickness change rate at the intersection points B1, B2 of the optical area 10 and the annular area 20 is less than 50%, and may even be less than 25%.

[0063] After substituting the parameters "P", "k1", and "k2" in Example 1 into formula (III), the area of ​​the arc-shaped cross section (A θ=0° , A θ=90° , Aθ=180° ) was calculated and the results are shown in Table 4. The area when the azimuth angle θ is 270° is the same as the area when the azimuth angle θ is 90°, so it will not be described again.

[0064] Furthermore, the ratio of the area of ​​the arc section when the azimuth angle θ is 180° to the area of ​​the arc section when the azimuth angle θ is 0° (A θ=180° / A θ=0° ), the ratio of the area of ​​the arc section when the azimuth angle θ is 90° to the area of ​​the arc section when the azimuth angle θ is 0° (A θ=90° / A θ=0° ), and the ratio of the area of ​​the arc section when the azimuth angle θ is 180° to the area of ​​the arc section when the azimuth angle θ is 90° (A θ=180° / A θ=90° ) is calculated. The calculation results are shown in Table 4.

[0065] [Example 2] The toric lens body 1 of Example 2 is similar to the toric lens body 1 of Example 1, except that the area of ​​the optical area cross section A1 is designed based on optometry data for an astigmatism power of 700°.

[0066] Through the calculation of formula (III), the area (design data) of the arc-shaped cross section under different azimuth angles can be obtained. By combining the optometry data and the design data, the area design of the annular area cross section A2 can be calculated.

[0067] After the design of the optical area cross section A1 and the annular area cross section A2 is completed, the optical area cross section A1 and the annular area cross section A2 are integrated to form an arc-shaped cross section, and then integrated along the direction of change in the azimuth angle to obtain the toric lens body 1 of Example 2.

[0068] Next, the thickness of the toric lens body 1 at the intersection point B1 (azimuth angle θ is 0°) and the intersection point B2 (azimuth angle θ is 180°) is measured, and the thickness difference and thickness change rate are calculated. The specific thicknesses, thickness difference, and thickness difference ratios at the intersection points B1 and B2 in Example 2 are listed in Table 3.

[0069] [Table 3]

[0070] According to the results in Table 3, even for a toric lens body 1 with a high degree of astigmatism (e.g., 700°), the thickness change rate at the intersection points B1 and B2 of the optical area 10 and the annular area 20 can be kept below 100%, which is lower than the thickness change rate of lenses in the existing technology (20% to 110%). Therefore, the present invention simultaneously considers the areas of the optical area 10 and the annular area 20, allowing the toric lens body 1 to have good positioning effect and wearing comfort.

[0071] Preferably, the change in thickness at the intersections B1, B2 of the optical area 10 and the annular area 20 is less than 75%, more preferably less than 55%. [Examples 3 to 9]

[0072] The toric lens body 1 of Examples 3 to 9 is similar to the toric lens body 1 of Example 1, but differs in that different parameters "P", "k1", and "k2" are substituted into formula (III). As a result, Examples 3 to 9 have different arcuate cross-sectional areas (design data).

[0073] In Examples 3 to 9, different parameters "P", "k1", and "k2" are substituted into formula (I), and the area of ​​the arc-shaped cross section (A θ=0° , A θ=90° , A θ=180° The calculation results are shown in Table 4. The area when the azimuth angle θ is 270° is the same as the area when the azimuth angle θ is 90°, so we will not repeat the description.

[0074] Furthermore, the ratio of the area of ​​the arc section when the azimuth angle θ is 180° to the area of ​​the arc section when the azimuth angle θ is 0° (A θ=180° / A θ=0° ), the ratio of the area of ​​the arc section when the azimuth angle θ is 90° to the area of ​​the arc section when the azimuth angle θ is 0° (A θ=90° / A θ=0°), and the ratio of the area of ​​the arc section when the azimuth angle θ is 180° to the area of ​​the arc section when the azimuth angle θ is 90° (A θ=180° / A θ=90° ) is calculated. The calculation results are shown in Table 4.

[0075] [Table 4]

[0076] From the results in Table 3, we can see that the area of ​​the arc-shaped cross section when the azimuth angle is 180° is 1.0 to 7.5 times the area when the azimuth angle is 0°. The area of ​​the arc-shaped cross section when the azimuth angle is 90° is 1.0 to 4.5 times the area when the azimuth angle is 0°. The area of ​​the arc-shaped cross section when the azimuth angle is 180° is 1.0 to 1.8 times the area when the azimuth angle is 90°.

[0077] [Examples 10 to 12] The toric lens body 1 of Examples 10 to 12 is similar to the toric lens body 1 of Example 1, except that different parameters "P," "a," "b," "c," and "d" are substituted into formula (II). As a result, Examples 10 to 12 have different arcuate cross-sectional areas (design data).

[0078] The parameters "P", "a", "b", "c" and "d" which are different in Examples 10 to 12 are substituted into the formula (II), and the area of ​​the arc-shaped cross section (A θ=0° , A θ=90° , A θ=180° ) was calculated. The calculation results are shown in Table 5.

[0079] In addition, the ratio of the area of ​​the arc section when the azimuth angle θ is 180° to the area of ​​the arc section when the azimuth angle θ is 0° (A θ=180° / A θ=0° ), the ratio of the area of ​​the arc section when the azimuth angle θ is 90° to the area of ​​the arc section when the azimuth angle θ is 0° (A θ=90° / A θ=0° ), and the ratio of the area of ​​the arc section when the azimuth angle θ is 180° to the area of ​​the arc section when the azimuth angle θ is 90° (A θ=180° / Aθ=90° ) are calculated and the results are shown in Table 5.

[0080] [Table 5]

[0081] From the results in Table 5, we can see that the area of ​​the arc-shaped cross section when the azimuth angle is 180° is 1.0 to 7.5 times the area when the azimuth angle is 0°. The area of ​​the arc-shaped cross section when the azimuth angle is 90° is 1.0 to 4.5 times the area when the azimuth angle is 0°. The area of ​​the arc-shaped cross section when the azimuth angle is 180° is 1.0 to 1.8 times the area when the azimuth angle is 90°.

[0082] [Beneficial Effects of the Embodiments] One beneficial effect of the present invention is that the contact lens provided by the present invention achieves both comfortable wearing and excellent rotational positioning performance through the technical solution that "the cross-sectional area A satisfies the formula (I) of A=Pf(θ)" and "θ is the azimuth angle, 0°≦θ≦360°, 0.5≦P≦7, and f(θ) is a polynomial."

[0083] Furthermore, the present invention uses a polynomial to optimize the cross-sectional area A=Pf(θ) of the toric lens body, and obtains different contact lenses through different polynomials f(θ) (e.g., Equation (II) and Equation (III)). Experiments have shown that using a trigonometric polynomial (e.g., Equation (III)) to design the cross-sectional area of ​​the toric lens body can more easily obtain contact lenses that meet customer requirements.

[0084] Furthermore, the arc-shaped cross section formed by the radial cross section of the toric lens body includes an optical area cross section and an annular area cross section. Therefore, in the contact lens manufacturing method provided by the present invention, the area of ​​the optical area cross section can be selectively designed first, and the area of ​​the annular area cross section can be calculated using formula (I). Alternatively, the area of ​​the annular area cross section can be designed first, and the area of ​​the optical area cross section can be calculated using formula (I). In this way, unlike conventional designs that only consider positioning effect, it is possible to manufacture contact lenses that combine both positioning effect and wearing comfort.

[0085] The contents disclosed above are merely preferred embodiments of the present invention, and do not limit the scope of the claims of the present invention. Therefore, all equivalent technical modifications made based on the contents of the specification and accompanying drawings of the present invention are intended to be included in the scope of the claims of the present invention. [Explanation of symbols]

[0086] 1 Toric lens body 10 Optical Area 20 Circular Area S1 External surface S2 inner surface O center C1 First curve C2 Second curve H Center section line A1 Optical area cross section A2 Circular Area Cross Section θ Azimuth r radial direction z thickness direction

Claims

1. 1. A contact lens comprising a toric lens body, the toric lens body has a radius extending radially outward from a center, and the toric lens body is configured such that a cross-sectional area A of the toric lens body in a thickness direction along the radius satisfies equation (I), A=P−f(θ); where θ is an azimuth angle, 0°≦θ≦360°, 0.5≦P≦7, f(θ) is a polynomial, and the units of A, P, and f(θ) are all mm 2 , and the azimuth angle is measured in a clockwise direction with the center of the toric lens body as the origin and the direction directly above the center as 0°; The toric lens body is divided into an optical area corresponding to a pupil size and an annular area surrounding the optical area, and the optical area and the annular area are concentrically arranged; f(θ) is a trigonometric polynomial expressed as [k1 sin(θ / 2) + k2 cos 2 (θ / 2)], where θ is the azimuth angle, 0°≦θ≦360°, −0.2≦k1≦0.5, 0≦k2≦6, and k2<P, and k1 and k2 cannot be 0 simultaneously. A contact lens characterized by:

2. 10. The contact lens of claim 1, wherein the maximum thickness change at the intersection of the optic area and the annular area of ​​the toric lens body is less than 100%.

3. 10. The contact lens of claim 1, wherein the maximum thickness change at the intersection of the optic area and the annular area of ​​the toric lens body is less than 55%.

4. 10. The contact lens of claim 1, wherein the ratio of the area of ​​the cross section of the toric lens body at an azimuth angle of 180 degrees to the area of ​​the cross section of the toric lens body at an azimuth angle of 0 degrees is between 1.0 and 7.

5.

5. 10. The contact lens of claim 1, wherein the ratio of the area of ​​the cross section of the toric lens body at an azimuth angle of 90 degrees to the area of ​​the cross section of the toric lens body at an azimuth angle of 0 degrees is between 1.0 and 4.

5.

6. 10. The contact lens of claim 1, wherein the ratio of the area of ​​the cross section of the toric lens body at an azimuth angle of 180 degrees to the area of ​​the cross section of the toric lens body at an azimuth angle of 90 degrees is between 1.0 and 1.

8.

7. The contact lens of claim 1 , wherein the cross-section of the toric lens body includes an optic area cross-section and an annular area cross-section.

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