Contact lens for post-keratectomy eye

Abstract

The present invention relates to a contact lens for a post-keratectomy eye, the contact lens comprising: a central portion having an eyeball-side spherical surface with a first radius of curvature; a buffer portion extending radially from the outer edge of the central portion and having an eyeball-side spherical surface with at least one radius of curvature; and an outer peripheral portion extending radially from the outer edge of the buffer portion and having an eyeball-side spherical surface with a second radius of curvature, wherein the first radius of curvature, the at least one radius of curvature of the buffer portion, and the second radius of curvature have different sizes.

Description

ocular contact lenses that have undergone corneal ablation

[0001] The present invention relates to a contact lens for a user who has undergone corneal ablation, and more specifically, to a lens comprising a central portion corresponding to the surgical site where corneal ablation was performed on the cornea of ​​the eye, an outer portion corresponding to the non-surgical site where corneal ablation was not performed, and having different radii of curvature for the central portion and the outer portion.

[0002] Generally, keratotomy is an ophthalmic surgery performed to improve vision by modifying the shape of the cornea. Representative examples include LASIK and LASEK, which are primarily performed to correct refractive errors or visual impairments. The cornea is the transparent outer layer of the eye that refracts light entering the eye to reach the iris and lens; during the keratotomy process, a portion of it may be excised or removed. Specifically, the corneal epithelium is excised, and a portion of the corneal stroma located within it is vaporized and removed using a laser. The surgical site where the stroma was removed can then be formed into a relatively flat surface. After the laser procedure, the surgery is completed by covering the excised corneal epithelium.

[0003] Representative corneal ablation procedures include LASIK (Laser-Assisted In Situ Keratomileusis), PRK (Photorefractive keratectomy), LASEK (Laser-Assisted subepithelial keratectomy), and SMILE (Small Incision Lenticule Extraction), and each of these ablation methods can correct vision by processing corneal tissue in a different way.

[0004] Specifically, LASIK (Laser-Assisted In Situ Keratomileusis) surgery involves using a surgical laser to make an incision inside the cornea and reshape the corneal tissue, and this ablation allows for relatively rapid recovery.

[0005] Additionally, PRK (Photorefractive keratectomy) uses a laser to modify the corneal surface; unlike LASIK, it does not involve an incision on the outer cornea and can correct vision by removing epithelial tissue from the corneal surface. The recovery period may be longer compared to LASIK.

[0006] In addition, LASEK (Laser-assisted subepithelial keratectomy) is similar to the aforementioned PRK but involves a treatment that partially protects the epithelial tissue to minimize inflammation on the corneal surface, while SMILE (Small Incision Lenticule Extraction) corrects vision by creating a small fragment inside the cornea using a laser and extracting it externally; it provides results similar to LASIK but may allow for a faster recovery period due to the smaller incision size.

[0007] Corneal resection surgery to correct vision is very popular worldwide, including in Korea, and the population that has undergone corneal resection is estimated to be about 5 million in Korea alone as of 2024, with men accounting for 25% and women 75% of the population.

[0008] Among those who have undergone keratotomy, there is a desire to wear cosmetic lenses such as colored lenses, but they are unable to do so due to the surgery. Additionally, there is an increasing demand for lenses that serve as therapeutic bandages after keratotomy, as well as lenses for individuals who have experienced myopia regression following the procedure.

[0009] When a corneal ablation is performed, the curvature of the corneal surface may change. In such cases, if standard lenses are used, a significant gap may occur between the base-curve (BC) of the lens touching the eye and the cornea, potentially causing problems such as tear accumulation, visual obstruction, and dry eye syndrome. Accordingly, conventional corneal correction contact lenses have been provided that slightly alter the shape of the cornea by applying a predetermined pressure to the surface of the eye, featuring a central radius of curvature larger than the central curvature of the cornea. However, this method of pressure application has the drawback of applying pressure directly to the cornea by the contact lens.

[0010] In addition, in the case of a standard hemispherical lens, it rests on the surface of the eyeball by tears, and due to eye movements and the blinking action of the eyelids, the lens rotates and moves up, down, left, and right. Due to this movement of the lens, the lens becomes decentered by about 1 mm from the center of the eyeball, and the lens can easily come into contact with and damage the vulnerable area of ​​the cornea where the corneal resection was performed.

[0011] To solve the above-mentioned problems, the present invention aims to provide a contact lens corresponding to the surface of an eye where corneal ablation has been performed, which improves optical characteristics and wearing comfort and protects the boundary between the surgical and non-surgical areas of the cornea by distinguishing a plurality of regions formed sequentially from the center of the lens toward the edge and varying their radii of curvature, thereby improving optical characteristics and wearing comfort.

[0012] To achieve the above objective, an ocular contact lens having undergone corneal ablation according to one embodiment of the present invention comprises: a central portion in which the ocular-side spherical surface is formed with a first radius of curvature; a buffer portion formed by extending radially from the outer edge of the central portion, in which the ocular-side spherical surface is formed with at least one radius of curvature; and an outer edge portion formed by extending radially from the outer edge of the buffer portion, in which the ocular-side spherical surface is formed with a second radius of curvature; wherein the first radius of curvature, the radius of curvature of the buffer portion, and the second radius of curvature are formed with different sizes.

[0013] In addition, the size may be formed to decrease sequentially in the order of the first radius of curvature, the radius of curvature of the buffer part, and the second radius of curvature.

[0014] In addition, the central portion, the buffer portion, and the outer edge portion may have the same inclination of the spherical surface on the eye side when viewed from a side cross-section at the boundary portions of each area.

[0015] In addition, the central portion is formed in an area between the center of the contact lens in planar form and a radius of 2 mm to 4.5 mm from the center, and the first radius of curvature of the central portion can be formed to be 9.4 mm to 10.0 mm.

[0016] In addition, the buffer portion is formed in an area between a radius of 2 mm to 4.5 mm and a radius of 5 mm to 6 mm from the center of the contact lens in a planar state, and the radius of curvature of the buffer portion can be formed to be 8.4 mm to 9.6 mm.

[0017] In addition, the outer edge is formed in the area between a radius of 5 mm to 6 mm from the center of the contact lens in planar form and the edge end of the contact lens, and the second radius of curvature of the outer edge can be formed to be 8.4 mm to 8.8 mm.

[0018] In addition, the buffer portion is divided into a first sub-buffer portion and a second sub-buffer portion in order from the center of the contact lens, and the first sub-buffer portion and the second sub-buffer portion may have different radii of curvature of the spherical surface on the eye side.

[0019] In addition, the radius of curvature of the first sub-buffer may be formed to be larger than the radius of curvature of the second sub-buffer.

[0020] In addition, the first sub-buffer and the second sub-buffer may have the same inclination of the spherical surface on the eye side when viewed from a side cross-section at the boundary portion between the first sub-buffer and the second sub-buffer.

[0021] Additionally, the first sub-buffer is formed in an area between a radius of 2 mm to 4.5 mm and a radius of 5 mm to 5.5 mm from the center of the contact lens in a planar state, and the radius of curvature of the first sub-buffer is formed to be 8.4 mm to 9.6 mm, and the second sub-buffer is formed in an area between a radius of 2.5 mm to 4.5 mm and a radius of 5 mm to 6 mm from the center of the contact lens in a planar state, and the radius of curvature of the second sub-buffer can be formed to be 8.4 mm to 9.6 mm.

[0022] In addition, when the first radius of curvature of the central part is 9.4 mm to 10.0 mm and the total area of ​​the contact lens is 100%, the ratio of the area of ​​the central part, the buffer part, and the outer edge part is 73:13:14, and the error in the ratio of the area of ​​each part may be within ±2%.

[0023] In addition, when the radius of curvature of the buffer portion is 8.9 mm to 9.2 mm and the total area of ​​the contact lens is 100%, the percentage ratio of the area of ​​the central portion, buffer portion, and outer rim portion is 73:13:14, and the error in the percentage ratio of the area of ​​each portion may be within ±2%.

[0024] The first radius of curvature of the central portion is 9.4 mm to 10.0 mm, and the boundary of the outer edge of the buffer portion is formed within the range of -0.25 mm to +0.25 mm at a radius of 5 mm to 6 mm from the center of the contact lens, and when the total area of ​​the contact lens is 100%, the ratio of the area of ​​the central portion, buffer portion, and outer edge portion is 73:13:14, and the error for each ratio of the area of ​​each portion may be within ±2%, ±5%, and ±5%, respectively.

[0025] Here, in the lateral cross-section of the contact lens, the central region area is the area defined by a vertical imaginary line passing through the center of the contact lens, a vertical imaginary line at the boundary between the central region and the buffer region, and a virtual line connecting both edges of the contact lens; the buffer region area is the area defined by a vertical imaginary line at the boundary between the central region and the buffer region, a vertical imaginary line at the boundary between the buffer region and the outer edge, and a virtual line connecting both edges of the contact lens; the outer edge region area is the area defined by a vertical imaginary line at the boundary between the buffer region and the outer edge, and a virtual line connecting both edges of the contact lens; and the total contact lens region area is the sum of the central, buffer, and outer edge region areas.

[0026] In addition, at least one of the outer edge portion and the buffer portion may further include a colored layer laminated on at least one surface among each inner surface and outer surface.

[0027] In addition, the contact lens may be any one of a soft lens, a hard lens, or a smart lens.

[0028] With the above-described solution, the present invention has the advantage of maintaining a wearing state through a central part, a buffer part, and an outer edge corresponding to the corneal shape where corneal ablation was performed.

[0029] In addition, even if the contact lens moves due to eye movement or the blinking action of the eyelids, direct contact of the lens with the boundary between the surgical site where the corneal ablation was performed and the non-surgical site where the corneal ablation was not performed can be reduced, thereby reducing continuous damage to the said boundary area.

[0030] In addition, by subdividing the above buffer section into a first sub-buffer section and a second sub-buffer section with different radii of curvature, optical characteristics and wearing comfort are further improved, and the boundary between the surgical site where corneal ablation was performed and the non-surgical site can be protected more effectively.

[0031] Figure 1 is a drawing showing an eyeball on which a corneal resection has been performed.

[0032] FIG. 2 is a side cross-sectional view of a contact lens divided into a central part, a buffer part, and an outer edge part according to the first embodiment of the present invention.

[0033] FIG. 3 is a drawing showing the shape according to the distance from the center of a contact lens according to the first embodiment of the present invention.

[0034] FIG. 4 is a drawing showing a state in which a contact lens according to the first embodiment of the present invention is placed on an eyeball that has undergone corneal resection.

[0035] Figure 5 is an enlarged view of part A in Figure 4.

[0036] FIG. 6 is a side cross-sectional view of a contact lens divided into a central portion, a first sub-buffering portion, a second sub-buffering portion, and an outer rim portion according to a second embodiment of the present invention.

[0037] FIG. 7 is a drawing showing the shape according to the distance from the center of a contact lens according to a second embodiment of the present invention.

[0038] FIG. 8 is a diagram showing the area of ​​the central part, buffer part, and outer edge part of the contact lens of the present invention.

[0039] FIG. 9 is a drawing showing a colored layer formed on a contact lens according to one embodiment of the present invention.

[0040] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, this is merely an example and the present invention is not limited thereto.

[0041] In describing the present invention, detailed descriptions of known technologies related to the invention are omitted if it is determined that such descriptions may unnecessarily obscure the essence of the invention. Furthermore, the terms described below are defined considering their functions in the present invention, and these definitions may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0042] The technical concept of the present invention is determined by the claims, and the following embodiments are merely a means to efficiently explain the technical concept of the present invention to those skilled in the art to which the present invention belongs.

[0043] The present invention relates to a contact lens for an eye that has undergone corneal ablation, wherein the contact lens according to an embodiment of the present invention is divided into a central portion, a buffer portion, and a buffer portion corresponding to the boundary between the surgical area and the non-surgical area, and is configured such that the radius of curvature of the spherical surface on the ocular side decreases in the order of the central portion, the buffer portion, and the outer edge, thereby improving optical characteristics and wearing comfort and reducing damage to the boundary between the surgical area and the non-surgical area caused by the movement of the lens.

[0044] Hereinafter, an ocular contact lens (100) having undergone refractive surgery, which is an embodiment of the present invention, will be described. First, regarding refractive surgery, it refers to a surgical procedure that changes the shape of the cornea for the purpose of vision correction. The cornea is an important part that controls the light's permeability and plays an important role in the process of light entering the eye, passing through the iris, and being refracted before reaching the retina. One of the main reasons for vision deterioration is when the curvature or thickness of the cornea deviates from the normal range, and refractive surgery may be performed to improve this problem.

[0045] Representative corneal ablation procedures, such as LASIK, PRK (Photorefractive keratectomy), LASEK (Laser-assisted subepithelial keratectomy), and SMILE (Small Incision Lenticule Extraction), all aim to improve vision by removing a portion of the cornea; however, the surface shape of the cornea may be partially altered after surgery. For example, a surgical area of ​​a certain diameter extending from the center of the eyeball may be removed using a laser, and the area may be formed into a flat shape.

[0046] If standard contact lenses are worn after such surgery, a void is created between the center of the eye and the center of the lens. The inner surface of the lens exposed to this void dries out rapidly, easily increasing eye fatigue due to dry eyes and consequently severely affecting wearing comfort.

[0047] In addition, when using a lens that is simply divided into two areas corresponding to the surgical site and the non-surgical site, there is a problem in that the boundary between the surgical site and the non-surgical site is continuously damaged by the movement of the contact lens.

[0048] Accordingly, the present invention provides a contact lens (100) that reduces the excessive empty space between the surgical site and the lens to provide an improved wearing comfort, and at the same time, reduces the direct contact between the surgical site and the non-surgical site of the cornea and the contact lens (100) by providing a cushioning structure in the part corresponding to the boundary area between the surgical site and the non-surgical site.

[0049] Referring to FIG. 1, when a corneal ablation is performed, the cornea (10) of the eye of the person undergoing the procedure is removed by laser treatment from the center by a predetermined diameter, so that the part of the cornea removed by the laser can have a relatively flat shape. Specifically, to remove the corneal stroma (12) of the cornea (10), the corneal epithelium (11) is ablated, and after the corneal stroma (12) inside is removed by laser treatment, the corneal epithelium (11) can be positioned to settle in the place where the corneal stroma was removed. Therefore, since the corneal epithelium (11) settles on the corneal stroma (12) that has been processed to be relatively flat, the central area of ​​the cornea (10), which is the laser-treated surgical site, has a flat shape.

[0050] FIG. 2 is a side cross-sectional view of a contact lens (100) according to a first embodiment of the present invention. FIG. 3 is a diagram showing the shape according to the distance from the center of the contact lens (100) according to a first embodiment of the present invention.

[0051] Referring to FIGS. 2 and 3, the spherical surface of a contact lens (100) according to a first embodiment of the present invention is divided into a plurality of regions. Specifically, the contact lens (100) according to the first embodiment of the present invention may include a central portion (110) formed with a first radius of curvature in a central region including the center of the contact lens (100), a buffer portion (120) formed by extending radially from the outer edge of the central portion (110) by at least one radius of curvature, and an outer edge portion (130) formed by extending radially from the outer edge of the buffer portion (120) by a second radius of curvature. In this specification, the radius of curvature, the first radius of curvature, and the second radius of curvature refer to the radius of curvature of the spherical surface on the eye side of the contact lens.

[0052] Here, the first radius of curvature, which is the radius of curvature of the central part (110), the radius of curvature of the buffer part (120), and the second radius of curvature, which is the radius of curvature of the outer edge part (130), can be formed to decrease sequentially. In other words, the radius of curvature of the buffer part (120) can be formed to a value between the first radius of curvature and the second radius of curvature.

[0053] The radius of curvature of the cornea of ​​a typical human eye is approximately 7.5 mm to 8.3 mm, which accounts for about 90% of the area. Traditionally, it is known that contact lenses (especially soft lenses) feel comfortable when the radius of curvature is about 0.6 mm larger than that of the human eye. Accordingly, most contact lenses sold on the market are manufactured with a radius of curvature of approximately 8.6 mm (there are various types ranging from 8.4 to 8.8 mm depending on the characteristics of the material and the purpose of the manufacturer, but most are around 8.6 mm). Meanwhile, when examining the curvature of the cornea after corneal ablation, the radius of curvature of the surgical area of ​​the cornea where surgery was performed by a laser is approximately 8.8 mm. If the radius of curvature of the central part (110), which corresponds to this area of ​​the contact lens, is set to 9.4 mm or more, which is an increase of 0.6 mm, a stable wearing comfort can be obtained. However, if the radius of curvature exceeds 10.0 mm, there is a risk that an excessive gap will occur between the surgical site of the cornea and the contact lens (100), which may reduce the wearing comfort.

[0054] Accordingly, the central portion (110) is an area corresponding to the surgical site where corneal resection was performed, and is formed in the area between the center of the contact lens (100) in plan view and a radius of 2 mm to 4.5 mm from the center, and the first radius of curvature of the central portion (110) can be formed to be 9.4 mm to 10.0 mm.

[0055] The area of ​​the eye through which light passes is related to the dilation and constriction of the pupil depending on the amount of light, and generally changes within 1 mm to 3 mm. In this regard, the area operated on by keratotomy is within a radius of approximately 4 mm. Through this surgery, the human eye takes on a flatter shape compared to the original shape up to a radius of about 4 mm from the center, while the area beyond that retains the original curvature of the eye. In other words, the cornea of ​​an eye that has undergone keratotomy has a boundary area between the surgical site and the non-surgical site where the radius of curvature changes.

[0056] Meanwhile, in the case of a standard contact lens, it rests on the surface of the eyeball by tears, and due to eye movements and the blinking action of the eyelids, the lens rotates and moves up, down, left, and right. Due to this movement of the lens, the lens becomes decentered by about 1 mm from the center of the eyeball, and due to this movement, the contact lens can easily come into contact with the boundary area between the surgical site and the non-surgical site and cause damage.

[0057] The above buffer portion (120) is an area corresponding to the boundary between the surgical area where corneal resection was performed and the non-surgical area where corneal resection was not performed, and is formed in an area between a radius of 2 mm to 4.5 mm and a radius of 5 mm to 6 mm from the center of the contact lens (100) in a planar view, and the radius of curvature of the buffer portion (120) can be formed to be 8.4 mm to 9.6 mm. The first embodiment of the present invention is provided with a buffer portion to reduce the contact lens (100) contacting the boundary area between the surgical area and the non-surgical area of ​​the cornea and causing continuous damage. This buffer portion (120) can be subdivided into two areas, which will be described later.

[0058] The outer rim (130) is an area corresponding to a non-surgical area where corneal resection has not been performed, and is formed in the area between a radius of 5 mm to 6 mm from the center of the contact lens (100) in a planar view and the edge end of the contact lens (100), and the second radius of curvature of the outer rim (130) can be formed to be 8.4 mm to 8.8 mm.

[0059] As described above, the first embodiment of the present invention provides a buffer portion (120) having a value between the radius of curvature of the central portion (110) (first radius of curvature) and the radius of curvature of the outer portion (130) (second radius of curvature) in the area between the central portion (110) corresponding to the surgical site where corneal ablation was performed and the outer portion (130) corresponding to the non-surgical site where corneal ablation was not performed. By providing a contact lens (100) corresponding to the shape of the eyeball where corneal ablation was performed, it is possible to provide an improved wearing comfort and reduce continuous damage to the boundary between the surgical site and the non-surgical site of the cornea caused by the movement of the contact lens (100). Specifically, when the first embodiment of the present invention is placed on the eyeball as shown in FIG. 4, a buffer portion (120) having a value between the radius of curvature of the surgical area and the non-surgical area is provided, so that a buffer space can be formed between the boundary portion between the surgical area and the non-surgical area and the contact lens (100) as shown in FIG. 5 (enlarged view of portion A in FIG. 4).

[0060] The central portion (110), buffer portion (120), and outer rim portion (130) of the contact lens (100) of the first embodiment of the present invention may have the same slope when viewed from the side at the boundary portion of each area. That is, at the boundary where the central portion (110) and the buffer portion (120) meet, the slope of the central portion (110) and the slope of the buffer portion (120) are the same when viewed from the side, and at the boundary where the buffer portion (110) and the outer rim portion (120) meet, the slope of the buffer portion (110) and the slope of the outer rim portion (120) are the same when viewed from the side.

[0061] In this case, the abrupt inflection at the boundary of each region can be suppressed to provide a more improved wearing comfort, and an appropriate space can be secured between the cushioning part (120) and the cornea.

[0062] Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7.

[0063] In the second embodiment of the present invention, the buffer portion (120) of the first embodiment is divided into a first sub-buffer portion (121) and a second sub-buffer portion (122), the first sub-buffer portion (121) is formed on the side of the central portion (110), and the second sub-buffer portion (122) is formed on the side of the outer edge portion (130), and the radius of curvature of the second sub-buffer portion (122) is formed to be smaller than the radius of curvature of the first sub-buffer portion (121). Other technical features are the same as those of the first embodiment, and redundant descriptions are omitted.

[0064] The first sub-buffer (121) is formed in an area between a radius of 2 mm to 4.5 mm and a radius of 5 mm to 5.5 mm from the center of the contact lens (100) in a planar view, and the radius of curvature of the first sub-buffer (121) can be formed to be 8.4 mm to 9.6 mm.

[0065] The second sub-buffer (122) is formed in an area between a radius of 2.5 mm to 4.5 mm and a radius of 5 mm to 6 mm from the center of the contact lens (100) in a planar view, and the radius of curvature of the second sub-buffer (121) can be formed to be 8.4 mm to 9.6 mm.

[0066] The slopes at the boundary between the first sub-buffer (121) and the second sub-buffer (122) may be formed identically when viewed from the side. That is, at the boundary where the first sub-buffer (121) and the second sub-buffer (122) meet, the slopes of the first sub-buffer (121) and the second sub-buffer (122) may be formed identically when viewed from the side.

[0067] In the second embodiment of the present invention, the cushioning portion (120) is formed by being divided into the first sub-cushioning portion (121) and the second sub-cushioning portion (122) as described above, thereby mitigating the change in the radius of curvature in the cushioning portion and providing a more improved wearing comfort.

[0068] The inventor of the present invention has discovered that, in the central portion (110), buffer portion (120), and outer portion (130) of the embodiment of the present invention, an improved wearing comfort is provided to an eye that has undergone corneal ablation according to the ratio of the area (hereinafter referred to as 'region area') defined by the curve of each region in a side cross-section, a virtual line in a vertical direction at the boundary portion of each region, a virtual line in a vertical direction passing through the center of the contact lens in a side cross-section, and a virtual line connecting the edge portion of the contact lens (100).

[0069] Referring to FIG. 8, when viewed from the side cross-section of the contact lens, the area of ​​the central part (110) (Area A) is the area of ​​the region defined by a virtual line in the vertical direction passing through the center of the contact lens, a curve of the central part (110), a virtual line in the vertical direction at the boundary between the central part (110) and the buffer part (120), and a virtual line connecting both ends of the edge of the contact lens (100); the area of ​​the buffer part (120) (Area B) is the area of ​​the region defined by a curve of the central part (110), a virtual line in the vertical direction at the boundary between the central part (110) and the buffer part (120), a virtual line in the vertical direction at the boundary between the buffer part (120) and the outer edge part (130), and a virtual line connecting both ends of the edge of the contact lens (100); and the area of ​​the outer edge part (130) (Area C) is the outer edge part (110) The area of ​​the region is defined by a virtual line in the vertical direction at the boundary between the curve, the buffer portion (120), and the outer edge portion (130), and a virtual line connecting both ends of the edge of the contact lens (100). The total area of ​​the contact lens (100) is the sum of the area of ​​the central portion (110), the buffer portion (120), and the outer edge portion (130).

[0070] Below, cases regarding the relationship between the area ratios of each region discovered by the inventor through experiments are described.

[0071] In the case of Case 1, in the above embodiment 1, the first radius of curvature of the central part (110) is 9.4 mm to 10.0 mm, and when the total area of ​​the contact lens (100) in the side cross-section of the contact lens (100) is 100%, the ratio of the area of ​​the central part (110), the buffer part (120), and the outer edge part (130) is 73:13:14, and the error in the ratio of the area of ​​each area may be within ±2%.

[0072] In the case of Case 2, in the above embodiment 1, the radius of curvature of the buffer portion (120) is 8.9 mm to 9.2 mm, and when the total area of ​​the contact lens (100) in the side cross-section of the contact lens (100) is 100%, the ratio of the area of ​​the central portion (110), the buffer portion (120), and the outer edge portion (130) is 73:13:14, and the error in the ratio of the area of ​​each area may be within ±2%.

[0073] In the case of Case 3, in the above embodiment 1, the first radius of curvature of the central part (110) is 9.4 mm to 10.0 mm, and the outer boundary of the buffer part (120) (radius 5 mm to 6 mm from the center) is adjusted in the range of -0.25 mm to +0.25 mm, and when the total area of ​​the contact lens (100) is 100% when viewed from the side cross-section of the contact lens (100), the ratio of the area of ​​the central part (110), the buffer part (120), and the outer edge part (130) is 73:13:14, and the error in the ratio of the area of ​​each area may be within ±2%, ±5%, and ±5%, respectively.

[0074] The inventors confirmed through experiments and simulations that in cases 1 to 3, the optical properties of the contact lens (100) are improved and the wearing comfort of the user who has undergone corneal ablation is improved.

[0075] Additionally, in each of the above cases, the buffer section (120) may be divided into a first sub-buffer section (121) and a second sub-buffer section (122), in which case the area ratio of the buffer section (120) is the sum of the area ratios of the first sub-buffer section (121) and the second sub-buffer section (122). For example, if the area ratio of the first sub-buffer section (121) is 7% and the area ratio of the second sub-buffer section (122) is 6%, the area ratio of the buffer section (120) may be 13%.

[0076] Below, the characteristic effects of the present invention are described through an evaluation of the wearing response during a test wear.

[0077] For the evaluation of the wearing response, five subjects with different ocular conditions wore the embodiment and comparative example of the present invention for 6 hours, and then a questionnaire was administered regarding central stability, CLDEQ, SPEED, ISS-14, and UNC-DEMS.

[0078] The eye condition of the subject refers to the radius of curvature of the region of the eye corresponding to the central part of the contact lens of the embodiment of the present invention (hereinafter referred to as the 'BC region'). The eye condition of the subject who participated in the test fitting is as shown in Table 1 below.

[0079] Subject 1 Subject 2 Subject 3 Subject 4 Subject 5 Right eye: 9.48mm Left eye: 9.43mm Right eye: 8.97mm Left eye: 9.00mm Right eye: 8.89mm Left eye: 8.84mm Right eye: 9.34mm Left eye: 9.32mm Right eye: 8.18mm Left eye: 8.24mm

[0080] Central stability refers to the degree to which the center of a contact lens remains within the center of the eye when worn; a lower value indicates better central stability.

[0081] CLEDQ and SPEED stand for "Contact Lens Dry Eye Questionnaire" and "Standard Patient Evaluation of Eye Dryness," respectively, and are international assessment methods that quantify contact lens comfort through questionnaires. For CLEDQ and SPEED, lower scores indicate better comfort.

[0082] ISS-14 is a survey method developed by the applicant of the present invention, which combines items related to wearing comfort such as foreign body sensation, itching, sandy sensation, dryness, redness, burning sensation, stinging, eye pain, glare, eye fatigue, tears, eye discharge, and visual impairment into a numerical value, and the higher the numerical value, the better the wearing comfort.

[0083] UNC-DEMS stands for the “University of North Carolina Dry Eye Management Scale,” an international assessment method that quantifies contact lens comfort through a survey. A higher score indicates better comfort.

[0084] <Wear Response Evaluation 1>

[0085] First, the embodiment of the present invention (central radius of curvature / cushioning radius of curvature / outer radius of curvature) was compared with Comparative Example 1 (radius of curvature 8.6 mm), in which the entire structure consists of a single radius of curvature. Five subjects each wore the embodiment and Comparative Example 1 for 6 hours and then conducted the CLDEQ, SPEED, ISS-14, and UNC-DEMS questionnaires. The average value of the questionnaire results from the five subjects was calculated. The results of the questionnaire are shown in Table 2 below.

[0086] Radius of curvature (mm) CLDEQSPEEDISS-14UNC-DEMS Comparative Example 18.6 14.5 57.2 08 3.6 6 5.33 Example 19.4 / 8.9 / 8.6 10.4 5.6 84.2 86.00 Example 29.6 / 8.9 / 8.6 10.6 6.8 86.6 67.00 Example 39.7 / 8.9 / 8.6 11.2 6.4 85.2 47.60 Example 49.8 / 8.9 / 8.6 7.4 3.4 90.9 68.80 Example 59.9 / 8.9 / 8.6 8.0 3.6 90.4 67.40 Example 6 10.0 / 8.9 / 8.6 3.0 2.5 94.3 39.25

[0087] As can be seen in Table 2 above, Examples 1 to 6 of the present invention showed superior comfort compared to Comparative Example 1 in all comfort survey indicators.

[0088] <Wear Response Evaluation 2>

[0089] Next, the embodiment of the present invention (central radius of curvature / cushioning radius of curvature / outer radius of curvature) was compared with Comparative Examples 2 to 4 (central radius of curvature / outer radius of curvature), which consist of two radii of curvature without a cushioning part. The five subjects each wore the embodiment and Comparative Example 1 for 6 hours and evaluated the central stability of the lens, and the average value of the evaluation results of the five subjects was calculated. The results of the evaluation are shown in Table 3 below.

[0090] Radius of Curvature (mm) Center Stability Example 7 9.5 / 8.9 / 8.6 0.63 Comparative Example 29.5 / 8.6 0.86 Example 89.6 / 8.9 / 8.6 0.39 Comparative Example 39.6 / 8.6 0.90 Example 99.8 / 8.9 / 8.6 0.60 Comparative Example 49.8 / 8.6 0.98

[0091] As can be seen in Table 3 above, the 3-curve lenses equipped with a buffer section as in the present invention and Examples 7 to 9 showed superior center stability compared to the 2-curve lenses not equipped with a buffer section as in Comparative Examples 2 to 4.

[0092] FIG. 8 is a drawing showing a contact lens (100b, 100c) according to one embodiment of the present invention, having a colored layer (140) on the inner surface or outer surface side.

[0093] Referring to FIG. 8, it may further include a colored layer (140) that is laminated on at least one of the inner surface and the outer surface, as shown in FIG. 8(a) and FIG. 8(b), and may be disposed on one or more of the buffer portion (120) and the outer surface, excluding the central portion (110).

[0094] The colored layer (140) can be formed by attaching it to the contact lens (100b, 100c) or by printing it, and can be expected to have aesthetic effects and functional effects such as selectively filtering specific wavelengths from light incident on the user's eye, like a light filter.

[0095] The contact lens (100) of the present invention is not limited to any type of contact lens that is worn on the eye, and can be applied to all types of lenses, such as soft lenses, hard lenses, smart lenses, etc.

[0096] Although representative embodiments of the present invention have been described in detail above, those skilled in the art will understand that various modifications can be made to the above-described embodiments without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims set forth below as well as equivalents thereof.

[0097] (Explanation of symbols)

[0098] 10: Cornea 11: Corneal epithelium

[0099] 12: Corneal stroma 13: Lens

[0100] 100, 100a, 100b, 100c: Contact lenses

[0101] 110: Central part 120: Buffer part

[0102] 121 : 1st sub-buffer 122 : 2nd sub-buffer

[0103] 130: Outer margin 140: Colored layer

[0104]

[0105] The present invention can be used in the field of contact lenses, particularly in the field of contact lenses for users who have undergone corneal ablation, as well as in similar or related fields, and can improve the reliability and competitiveness of products in said fields.

Claims

1. A central portion in which the spherical surface on the eye side is formed with a first radius of curvature; A buffer portion formed by extending radially from the outer edge of the central portion above, wherein the spherical surface on the eye side is formed with at least one radius of curvature; and It includes an outer edge portion formed by extending radially from the outer edge of the above buffer portion, wherein the spherical surface on the eye side is formed with a second radius of curvature; Characterized that the first radius of curvature, the radius of curvature of the buffer portion, and the second radius of curvature are formed with different sizes. Ocular contact lens on which a corneal ablation has been performed.

2. In Paragraph 1, Characterized by being formed such that the size decreases sequentially in the order of the first radius of curvature, the radius of curvature of the buffer part, and the second radius of curvature. Ocular contact lens on which a corneal ablation has been performed.

3. In Paragraph 2, The above central portion, the above buffer portion, and the above outer edge portion are characterized by having the same inclination of the spherical surface on the eye side when viewed from a side cross-section at the boundary portions of each region. Ocular contact lens on which a corneal ablation has been performed.

4. In any one of paragraphs 1 to 3, The above central portion is formed in the area between the center of the contact lens in planar form and a radius of 2 mm to 4.5 mm from the center, and Characterized by the first radius of curvature of the central portion being formed to be 9.4 mm to 10.0 mm. Ocular contact lens on which a corneal ablation has been performed.

5. In any one of paragraphs 1 to 3, The above buffer portion is formed in an area between a radius of 2 mm to 4.5 mm and a radius of 5 mm to 6 mm from the center of the contact lens in a planar view, and Characterized by the radius of curvature of the above buffer being formed to be 8.4 mm to 9.6 mm, Ocular contact lens on which a corneal ablation has been performed.

6. In any one of paragraphs 1 to 3, The above outer periphery is formed in the area between a radius of 5 mm to 6 mm from the center of the contact lens in planar form and the edge end of the contact lens, Characterized by the second radius of curvature of the outer edge being formed to be 8.4 mm to 8.8 mm. Ocular contact lens on which a corneal ablation has been performed.

7. In any one of paragraphs 1 to 3, The above buffer section is divided into a first sub-buffer section and a second sub-buffer section in order from the center of the contact lens, and The first sub-buffer and the second sub-buffer are characterized by having different radii of curvature on the spherical surface on the eye side. Ocular contact lens on which a corneal ablation has been performed.

8. In Paragraph 7, Characterized in that the radius of curvature of the first sub-buffer is formed to be larger than the radius of curvature of the second sub-buffer. Ocular contact lens on which a corneal ablation has been performed.

9. In Paragraph 8, The first sub-buffer and the second sub-buffer are characterized in that the inclination of the spherical surface on the eye side in a side cross-section is formed identically at the boundary portion between the first sub-buffer and the second sub-buffer. Ocular contact lens on which a corneal ablation has been performed.

10. In Paragraph 7, The first sub-buffer is formed in an area between a radius of 2 mm to 4.5 mm and a radius of 5 mm to 5.5 mm from the center of the contact lens in a planar state, and The radius of curvature of the first sub-buffer is formed to be 8.4 mm to 9.6 mm, and The second sub-buffer is formed in an area between a radius of 2.5 mm to 4.5 mm and a radius of 5 mm to 6 mm from the center of the contact lens in a planar state, and Characterized by the radius of curvature of the second sub-buffer being formed to be 8.4 mm to 9.6 mm. Ocular contact lens on which a corneal ablation has been performed.

11. In any one of paragraphs 1 to 3, The first radius of curvature of the central portion is 9.4 mm to 10.0 mm, and An ocular contact lens on which a corneal ablation has been performed, characterized in that, when the total area of ​​the contact lens is 100%, the ratio of the area of ​​the central part, the buffer part, and the outer edge part is 73:13:14, and the error for each ratio of the area of ​​each part is within ±2%. (Here, in the lateral cross-section of the contact lens, the central region area is the area defined by a vertical imaginary line passing through the center of the contact lens, a vertical imaginary line at the boundary between the central region and the buffer region, and a virtual line connecting both edges of the contact lens; the buffer region area is the area defined by a vertical imaginary line at the boundary between the central region and the buffer region, a vertical imaginary line at the boundary between the buffer region and the outer edge, and a virtual line connecting both edges of the contact lens; the outer edge region area is the area defined by a vertical imaginary line at the boundary between the buffer region and the outer edge, and a virtual line connecting both edges of the contact lens; and the total contact lens region area is the sum of the central, buffer, and outer edge region areas.) 12. In any one of paragraphs 1 to 3, The radius of curvature of the above buffer is 8.9 mm to 9.2 mm, and An ocular contact lens on which a corneal ablation has been performed, characterized in that, when the total area of ​​the contact lens is 100%, the ratio of the area of ​​the central part, the buffer part, and the outer edge part is 73:13:14, and the error for each ratio of the area of ​​each part is within ±2%. (Here, in the lateral cross-section of the contact lens, the central region area is the area defined by a vertical imaginary line passing through the center of the contact lens, a vertical imaginary line at the boundary between the central region and the buffer region, and a virtual line connecting both edges of the contact lens; the buffer region area is the area defined by a vertical imaginary line at the boundary between the central region and the buffer region, a vertical imaginary line at the boundary between the buffer region and the outer edge, and a virtual line connecting both edges of the contact lens; the outer edge region area is the area defined by a vertical imaginary line at the boundary between the buffer region and the outer edge, and a virtual line connecting both edges of the contact lens; and the total contact lens region area is the sum of the central, buffer, and outer edge region areas.) 13. In any one of paragraphs 1 to 3, The first radius of curvature of the central portion is 9.4 mm to 10.0 mm, and The boundary of the outer edge of the buffer portion is formed within a range of -0.25 mm to +0.25 mm at a radius of 5 mm to 6 mm from the center of the contact lens, and Characterized by the fact that, when the total area of ​​the contact lens is 100%, the percentage ratio of the area of ​​the central part, the buffer part, and the outer edge part is 73:13:14, and the error for each percentage ratio of the area of ​​each part is within ±2%, ±5%, and ±5%, respectively. Ocular contact lens on which a corneal ablation has been performed. (Here, in the lateral cross-section of the contact lens, the central region area is the area defined by a vertical imaginary line passing through the center of the contact lens, a vertical imaginary line at the boundary between the central region and the buffer region, and a virtual line connecting both edges of the contact lens; the buffer region area is the area defined by a vertical imaginary line at the boundary between the central region and the buffer region, a vertical imaginary line at the boundary between the buffer region and the outer edge, and a virtual line connecting both edges of the contact lens; the outer edge region area is the area defined by a vertical imaginary line at the boundary between the buffer region and the outer edge, and a virtual line connecting both edges of the contact lens; and the total contact lens region area is the sum of the central, buffer, and outer edge region areas.) 14. In any one of paragraphs 1 to 3, At least one of the above outer edge and the above buffer portion is, Characterized by further including a colored layer laminated on at least one surface among each inner surface and outer surface. Ocular contact lens on which a corneal ablation has been performed.

15. In any one of paragraphs 1 to 3, The above contact lens is characterized as being one of a soft lens, a hard lens, a smart lens, or a color lens. Ocular contact lens on which a corneal ablation has been performed.

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