Scleral contact lens and its fitting method

Abstract

The present disclosure describes a scleral contact lens, which includes an optical zone, a mid-peripheral zone, and a landing zone formed in sequence from the inside out. In a longitudinal section along the sagittal height direction of the scleral contact lens, the inner surface of the landing zone is an arc curve with the center of the circle located on the outer surface side of the scleral contact lens, and the arc curve satisfies: where r is the radius of the arc curve, c is the arch height of the arc curve, d is the radial distance between the two ends of the arc curve in the radial direction of the scleral contact lens, and α is the angle between the straight line segment defined by the two ends of the arc curve and the radial direction of the scleral contact lens, and the angle α satisfies: 28° ≤ α ≤ 50°. According to the present disclosure, it is possible to provide a scleral contact lens that can be well matched with the sclera and is easy to fit. In addition, the present disclosure also describes two methods for fitting the scleral contact lens.

Description

Technical Field

[0001] The present invention generally relates to the field of ophthalmic medical devices, and particularly relates to a scleral contact lens and a method for fitting the same. Background Art

[0002] Contact lenses can correct refractive errors of the eyeball. Commonly used rigid contact lenses directly contact the cornea and are worn on the cornea. However, since the cornea contains abundant sensory nerve cells and is a relatively sensitive part of the human body, wearing rigid contact lenses directly on the cornea easily causes a foreign body sensation or other uncomfortable symptoms, and these symptoms are more serious for patients suffering from corneal diseases (such as keratoconus, dry eye syndrome), etc. In addition, for patients with irregular corneal refractive errors, it is difficult to obtain clear and comfortable corrected vision through ordinary rigid or soft contact lenses.

[0003] Regarding the above problems, the prior art has proposed a scleral lens that does not contact the cornea but lands on the scleral area outside the corneal limbus. Specifically, by increasing the diameter of the spectacle lens so that the lens is larger than the overall cornea, all the contact points of the lens with the eye surface are changed from the cornea to the relatively insensitive sclera, so as to reduce the risk of damage to the pathological cornea and reduce the presence of foreign body sensation. In particular, for some patients with damaged corneal tissue, the scleral lens can form an ample tear space behind the lens, and the tear bath can protect the cornea and accelerate corneal epithelial healing. Moreover, since the tear lens under the scleral lens can well compensate for the irregularity of the pathological cornea, it is also particularly suitable for refractive errors caused by irregular corneas.

[0004] When the scleral lens is worn on the eyeball, the landing area contacts the sclera covered by the bulbar conjunctiva. Since the bulbar conjunctiva covering the sclera is loose connective tissue, the lens will settle when the landing area contacts the sclera. The landing areas of existing scleral lenses are usually designed as curves or tangents. Among them, in the scleral lens with a curved landing area design, the landing area is generally set to have a concave configuration matching the corresponding area of the sclera. For such scleral lenses, it is very difficult to make the shape of the landing area match the shape of the corresponding position of the sclera during actual processing, which may cause poor contact between the scleral lens and the corresponding position of the sclera, and the lens edge may be embedded in the sclera when the lens settles, resulting in poor wearing effect and comfort of the scleral lens. In the scleral lens with a tangent landing area design, since the scleral shape (the area corresponding to most of the scleral lens landing areas) presents a state close to a tangent, some prior art landing areas adopt a tangent design. However, the scleral shapes of each person are different, and at a fixed chord length, the angles of the scleral tangents are also different. If the tangent angle of the landing area is not exactly the same as the tangent angle of the sclera, the lens edge will be embedded in the sclera when the lens settles, resulting in a difference between the wearing effect of the scleral lens and the theoretically ideal state, and the comfort during wearing is not high. Summary of the Invention

[0005] In light of the above-mentioned existing situation, the present disclosure aims to provide a scleral contact lens that is well-matched with the sclera and easy to fit, as well as a method for fitting the lens. The scleral contact lens of the present disclosure can be adapted to sclera of varying shapes, ensuring uniform load-bearing on the sclera, thereby improving patient comfort.

[0006] To this end, a first aspect of the present disclosure provides a scleral contact lens, comprising an optical zone, a mid-peripheral zone surrounding the periphery of the optical zone, and a landing zone surrounding the periphery of the mid-peripheral zone, formed sequentially from the inside out. When the scleral contact lens is worn, a tear lens is formed between the optical zone and the cornea to hold tears for vision correction. The inner surface of the landing zone contacts the sclera. In a longitudinal section along the sagittal direction of the scleral contact lens, the inner surface of the landing zone is an arc curve with its center located on one side of the outer surface of the scleral contact lens, and the arc curve satisfies:

[0007]

[0008] Wherein, r is the radius of the circular arc curve, c is the arch height of the circular arc curve, d is the radial distance between the two ends of the circular arc curve along the radial direction of the scleral contact lens, α is the angle between the straight line segment defined by the two ends of the circular arc curve and the radial direction of the scleral contact lens, and the angle α satisfies: 28°≤α≤50°.

[0009] In the present disclosure, by configuring the inner surface of the landing zone as an arc curve with its center located on one side of the outer surface of the scleral contact lens (inverse arc design), the impact of the lens edge on the conjunctival tissue can be reduced (for example, the occurrence of the lens edge embedding into the sclera is reduced), and the outward-curved arc-shaped landing zone can adapt to different forms of sclera, thereby improving the wearing comfort of the scleral contact lens and reducing the precision requirements of the scleral lens manufacturing process. In addition, by configuring the angle α between the straight line segments defined by the two ends of the arc curve and the radial direction of the scleral contact lens to satisfy: 28°≤α≤50°, when substituting it into the calculation formula of the arc curve, the arc curve can be adapted to the scleral angle of most human eyes (i.e., the angle between the sclera and the iris plane). As long as the angle α is roughly consistent with the scleral angle of the target human eye, the purpose of reducing the pressure of the landing zone of the scleral contact lens on the conjunctival blood vessels during wear can be achieved, thereby improving the wearing effect, safety, and comfort of the scleral contact lens. In addition, since the scleral contact lens of the present invention has high adaptability to different forms of sclera, it can also simplify the fitting process, and can achieve a good wearing effect even if there is a certain gap.

[0010] In addition, in the scleral contact lens involved in the present disclosure, optionally, the radial distance d at both ends of the arc curve satisfies: 1.3 mm ≤ d ≤ 1.7 mm, and the arch height c of the arc curve satisfies: 0.020 mm ≤ c ≤ 0.075 mm. When worn, if the tilt angle of the landing area is too high, it may reduce the comfort of wearing the scleral lens, while if the tilt angle is too low, it is likely to adhere to the sclera. In this case, with the radial distance d and arch height c within this range, the height at which the scleral lens tilts outwards can be within a certain range, which can reduce the discomfort / foreign body sensation caused by the tilting of the lens edge during wearing, thereby improving the comfort during wearing, and also facilitating the reduction of the generation of air bubbles under the lens. After setting the included angle α, radial distance d, and arch height c as above, the landing area of the scleral contact lens has a fixed shape, and this area is not restricted by other areas of the scleral contact lens. According to the inventor's research, based on the concept of the above specific landing area of the present invention, the scleral contact lens with the included angle α, radial distance d, and arch height c within this numerical range is particularly suitable for the eyeball structure of Asian eyes.

[0011] In addition, in the scleral contact lens involved in the present disclosure, optionally, the radius r of the arc curve satisfies: 4.1 mm ≤ r ≤ 31.1 mm. In this case, the radial distance d and arch height c at both ends of the arc curve are within a certain range, which can help reduce the discomfort / foreign body sensation caused by the tilting of the lens edge during wearing, thereby improving the comfort during wearing.

[0012] In addition, in the scleral contact lens involved in the present disclosure, optionally, the central angle θ of the arc curve satisfies: 4.4° ≤ θ ≤ 22°. In this case, the radial distance d and arch height c at both ends of the arc curve are within a certain range, which can help reduce the discomfort / foreign body sensation caused by the tilting of the lens edge during wearing, thereby improving the comfort during wearing.

[0013] In addition, in the scleral contact lens involved in the present disclosure, optionally, the distance between the center of the scleral contact lens and the center of the landing area in the radial direction of the scleral contact lens is 6.3 mm to 8.3 mm. In this case, the position of the landing area of the scleral contact lens can be adapted to the scleral size of most human eyes.

[0014] In addition, in the scleral contact lens involved in the present disclosure, optionally, the landing zone is non-rotationally symmetric. In this case, non-rotational symmetry means that the landing zone of the scleral contact lens is designed specifically for each quadrant, and the scleral shape of the human eye also varies in different quadrants. Therefore, by setting the landing zone to be non-rotationally symmetric, the landing zone has different included angles α, vault heights c, and / or radial distances d in at least two meridian directions, so that the landing zones of each quadrant can match the scleral shape of the corresponding quadrant, thereby further improving the overall matching degree of the scleral lens with the target eyeball.

[0015] In addition, in the scleral contact lens involved in the present disclosure, optionally, in the longitudinal section along the sagittal height direction of the scleral contact lens, the inner surface of the mid-peripheral zone is linear. Thereby, it is beneficial for the mid-peripheral zone to match the cornea, that is, the mid-peripheral zone can better match the peripheral zone of the cornea.

[0016] In addition, in the scleral contact lens involved in the present disclosure, optionally, it further includes a limbal zone formed between the mid-peripheral zone and the landing zone and in a ring shape. In this case, through the limbal zone, the mid-peripheral zone and the landing zone can be connected, and the inner surface of the mid-peripheral zone corresponding to a sectional shape can be smoothly transitioned to the inner surface of the landing zone corresponding to a curved surface shape.

[0017] In addition, in the scleral contact lens involved in the present disclosure, optionally, the radius of curvature of the inner surface of the limbal zone is greater than the radius of curvature of the inner surface of the landing zone. In this case, it is convenient to smoothly connect the mid-peripheral zone and the landing zone.

[0018] In addition, in the scleral contact lens involved in the present disclosure, optionally, the included angle α is adjusted such that when the user wears the scleral contact lens, the scleral contact lens contacts the sclera of the user at the central position of the arc curve. In this case, the central part of the landing zone contacts the sclera during wearing, which is beneficial to improving the wearing stability of the scleral contact lens. When the user performs strenuous exercise, even if the scleral contact lens vibrates in the eye, it will not cause damage to the surface of the eyeball.

[0019] The second aspect of the present disclosure provides a method for fitting a scleral contact lens, which includes the following steps: Step 1, preset the included angle α to 36° to select the preset scleral contact lens; Step 2, after coloring at least one mark on the outer edge of the inner surface or the outer surface of the scleral contact lens, try it on the user; Step 3, enable the user to blink at a frequency of 2 times per second to 5 times per second for at least 3 times, and observe whether the scleral contact lens rotates by observing the mark; Step 4, when the scleral contact lens does not rotate, reduce the included angle α by a step of 1° or 2° to select a new scleral contact lens, and then repeat Steps 2 to 4; when the scleral contact lens rotates and the position of the scleral contact lens is different after each blink, increase the included angle α by a step of 1° or 2° to select a new scleral contact lens, and then repeat Steps 2 to 4; when the scleral contact lens rotates and the position of the mark of the scleral contact lens is basically the same after at least two blinks, determine the parameters of the scleral contact lens and complete the fitting.

[0020] In the fitting method related to the second aspect of the present disclosure, since the scleral angle of the general human eye is in the range of 31.4°–44.6°, by presetting the included angle α of the scleral contact lens in the initial form to 36° in Step 1, the number of times of adjusting the degree of the included angle α in the subsequent steps can be reduced, and the fitting efficiency can be improved; in Step 2, by adding a mark on the lens, it is convenient to observe the rotation amplitude of the lens in the subsequent steps; in Steps 3 and 4, the fitting degree (i.e., the tightness degree) of the scleral contact lens and the target eyeball is judged by observing the rotation amplitude of the lens, and appropriate adjustment is made according to the actual situation; when the position of the mark of the scleral contact lens is basically the same after the blink ends after adjustment, that is, when the included angle α of the scleral contact lens is basically the same as the scleral angle of the target eyeball, the parameters of the scleral contact lens with a moderate tightness degree matching the target eyeball can be obtained, and the fitting is completed; in addition, the fitting method of the present disclosure is also helpful for fitting a scleral lens for an irregular cornea, and can also solve problems such as inaccurate curvature caused by corneal damage to a certain extent.

[0021] In addition, in the fitting method related to the second aspect of the present disclosure, optionally, the time interval between two adjacent blinks is set between 0.5 seconds and 2 seconds. In this case, since the number of blinks per minute of the general person is about 10-20 times, when wearing an intraocular endoscope, there may be a foreign body sensation resulting in an increase in the blinking frequency. At this time, by setting the time interval between two adjacent blinks to between 0.5 seconds and 2 seconds, the situation of the lens rotating / displacing under the conditions of daily wearing of the intraocular endoscope and / or frequent use of the eyes can be simulated, so that the parameters of the scleral contact lens adapted to the target eyeball can be further obtained.

[0022] In addition, in the fitting method according to the second aspect of the present disclosure, optionally, after the scleral contact lens stops rotating, the next blink is performed. In this case, it is possible to facilitate the observation of the actual rotation amplitude of the scleral contact lens, so that the parameters of the scleral contact lens adapted to the target eyeball can be further obtained.

[0023] The third aspect of the present disclosure provides a fitting method for a scleral contact lens, which includes the following steps: Step 10, presetting the included angle α to 36° to select the scleral contact lens in the initial form; Step 20, trying on the scleral contact lens on the user; Step 30, after waiting for a predetermined time, observing under a slit lamp whether any one of the following phenomena occurs at the edge of the user's sclera corresponding to the scleral contact lens: a significant change in the blood vessel diameter, blood vessel interruption, a circular white and shiny sclera, or a circular black shadow; Step 40, when any one of the phenomena of a significant change in the blood vessel diameter, blood vessel interruption, or a circular white and shiny sclera occurs, reducing the included angle α by at least 1° to select a new scleral contact lens, and then repeating Step 20 to Step 40; when a circular black shadow appears, increasing the included angle α by 1° or 2° to select a new scleral contact lens, and then repeating Step 20 to Step 40; when none of the phenomena of a significant change in the blood vessel diameter, blood vessel interruption, a circular white and shiny sclera, or a circular black shadow is found, determining the parameters of the scleral contact lens to complete the fitting.

[0024] In the fitting method according to the third aspect of the present disclosure, since the scleral angle of the general human eye is in the range of 31.4°–44.6°, by presetting the included angle α of the scleral contact lens in the initial form to 36° in Step 10, it is possible to reduce the number of times of adjusting the degree of the included angle α in the subsequent steps and improve the fitting efficiency; in Step 30 and Step 40, the scleral condition of the user can be clearly observed through a slit lamp, and the degree of the included angle α is adjusted based on the scleral condition. When the sclera shows no abnormality after adjustment, the parameters of the scleral contact lens with a moderate tightness matching the target eyeball can be obtained to complete the fitting. At this time, the included angle α of the scleral contact lens is basically the same as the scleral angle of the target eyeball. In addition, the fitting method of the present disclosure is also helpful for fitting a scleral lens for an irregular cornea and can also solve problems such as inaccurate curvature caused by corneal damage to a certain extent.

[0025] In addition, in the fitting method according to the third aspect of the present disclosure, optionally, the predetermined time is not less than 1 hour. Thus, it is possible to simulate the wearing effect of the scleral lens fully settling on the sclera during daily wearing of the scleral lens, so as to obtain the parameters of the scleral contact lens that are further adapted to the target eyeball.

[0026] In addition, in the spectacle fitting method according to the third aspect of the present disclosure, optionally, when there is an obvious change in the blood vessel diameter, the included angle α is decreased in steps of 1° or 2° to select a new scleral contact lens, and then steps 20 to 40 are repeated; and / or when blood vessel cutoff is found, the included angle α is decreased in steps of 3° or 4° to select a new scleral contact lens, and then steps 20 to 40 are repeated; and / or when a circular white and shiny sclera is found, the included angle α is decreased in steps of 5° or 6° to select a new scleral contact lens, and then steps 20 to 40 are repeated. In this case, the decreasing step of the included angle α can be adaptively adjusted according to scleral conditions of different severities, thereby improving the efficiency of fitting.

[0027] According to the present disclosure, it is possible to provide a scleral contact lens that can be well matched with the sclera and can evenly disperse the pressure borne by the sclera, and a spectacle fitting method for two scleral contact lenses. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a diagram showing an application scenario of a scleral lens according to an example of the present disclosure.

[0029] Figure 2 is a three-dimensional schematic diagram of a scleral lens according to an example of the present disclosure.

[0030] Figure 3 is a cross-sectional schematic diagram of an eyeball according to an example of the present disclosure.

[0031] Figure 4 is a cross-sectional schematic diagram of a scleral lens according to an example of the present disclosure.

[0032] Figure 5A is a schematic diagram of a first state in which a landing area contacts the sclera according to an example of the present disclosure.

[0033] Figure 5B is a schematic diagram of a second state in which a landing area contacts the sclera according to an example of the present disclosure.

[0034] Figure 6 is a bottom view of the inner surface of a scleral lens according to an example of the present disclosure.

[0035] Figure 7 is a flowchart of a first spectacle fitting method according to an example of the present disclosure.

[0036] Figure 8 is a flowchart of a second spectacle fitting method according to an example of the present disclosure.

[0037] Figure 9 is a schematic diagram of various scleral states under a slit lamp according to an example of the present disclosure.

[0038] Description of Reference Numerals

[0039] 1... Scleral lens, 10... Outer surface, 20... Inner surface, 30... Optical zone, 40... Mid-peripheral zone, 50... Limbal zone, 60... Landing zone, 8... Tear space, 9... Eye, 91... Cornea, 92... Sclera. Detailed Description of the Embodiment

[0040] All references cited in this disclosure are incorporated herein by reference in their entirety as if fully set forth. Unless otherwise defined, the technical and scientific terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0041] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals are given to the same components, and repeated descriptions are omitted. In addition, the drawings are only schematic diagrams, and the proportional relationship of the sizes between components or the shapes of components may be different from the actual ones.

[0042] The present disclosure relates to a scleral contact lens, which is a scleral contact lens that lands on the sclera when worn and forms a tear space between the inner surface of the lens and the anterior surface of the cornea for refractive correction. The scleral contact lens of the present disclosure can be abbreviated as a "scleral lens", which belongs to a type of contact lens. Through the scleral contact lens involved in the present disclosure, it can be well matched with the sclera when worn and is easy to fit.

[0043] Hereinafter, the scleral contact lens involved in the present disclosure will be described with reference to the accompanying drawings.

[0044] Figure 1 It is a diagram showing the application scenario of the scleral lens 1 involved in the example of the present disclosure. Figure 2 It is a three-dimensional schematic diagram showing the scleral lens 1 involved in the example of the present disclosure.

[0045] In the present embodiment, the scleral lens 1 may include an outer surface 10 and an inner surface 20 (see Figure 1 ). The outer surface 10 may be the surface relatively far from the eye 9 when worn, and the inner surface 20 may be the surface in contact with the eye 9 when worn.

[0046] In the present embodiment, the scleral lens 1 may include an optical zone 30 formed successively from the inside out, a mid-peripheral zone 40 surrounding the outer periphery of the optical zone 30, and a landing zone 60 (illustrated later) surrounding the outer periphery of the mid-peripheral zone 40. In some examples, when the scleral lens 1 is worn, a tear lens for accommodating tears to correct vision may be formed between the optical zone 30 and the cornea 91, and the inner surface 20 of the landing zone 60 may contact the sclera 92. In other words, when worn, there may be a gap between the optical zone 30 and the cornea 91, and the scleral lens 1 may land on the sclera 92 through the landing zone 60. Thus, a scleral lens 1 with a vision correction effect can be formed.

[0047] In some examples, as Figure 1 shown, when the scleral lens 1 is worn on the eyeball 9, the scleral lens 1 does not contact the cornea 91. Thus, even if the patient wearing it has an irregular cornea, it will not affect the wearing of the scleral lens 1.

[0048] Figure 3 is a schematic cross-sectional view of the eyeball 9 involved in the example of the present disclosure. Figure 4 is a schematic cross-sectional view of the scleral lens 1 involved in the example of the present disclosure. Among them, Figure 3 is a longitudinal section along the elevation direction of the eyeball 9.

[0049] Figure 5A is a schematic view of the first state in which the landing zone 60 contacts the sclera 92 involved in the example of the present disclosure. Figure 5B is a schematic view of the second state in which the landing zone 60 contacts the sclera 92 involved in the example of the present disclosure. In Figure 5A and Figure 5B , the point P schematically represents the midpoint of the inner surface 20 of the landing zone 60 (i.e., at the central position of the arc curve); in addition, it should be noted that, in order to more clearly illustrate the contact situation between the landing zone 60 and the sclera 92, in Figure 5A and Figure 5B , some lines of the scleral lens 1 are omitted, and the warping height of the arc curve and the deformation situation of the sclera 92 are adaptively enlarged.

[0050] In some examples, in the longitudinal section along the elevation direction of the scleral lens 1, the inner surface 20 of the landing zone 60 is an arc curve with the center of the circle located on the outer surface 10 side of the scleral lens 1 (see Figure 5AIn this case, the landing zone 60 is designed with an inverse arc, which can reduce the impact of the lens edge on the conjunctival tissue (for example, reducing the possibility of the lens edge digging into the sclera 92). The outward-curved arc-shaped landing zone 60 can adapt to different shapes of sclera 92, thereby improving the wearing comfort of the scleral lens 1. At the same time, due to the use of a backward arc design, even if the manufacturing precision of the scleral lens 1 is slightly reduced, the scleral lens 1 manufactured by the factory can still better match the human eye.

[0051] In some examples, the circular arc curve satisfies:

[0052]

[0053] Wherein, r is the radius of the arc curve, c is the arch height of the arc curve, d is the radial distance between the two ends of the arc curve along the radial direction of the scleral lens 1, and α is the angle α between the straight line segment defined by the two ends of the arc curve and the radial direction of the scleral lens 1. It should be noted that the radial direction of the scleral lens 1 refers to the perpendicular direction from the center of the scleral lens 1 to the edge thereof.

[0054] In some examples, the angle α satisfies: 28°≤α≤50°. Since the sclera 92 is close to a tangent line, the sclera 92 is considered as a tangent line, and the angle β between the sclera 92 tangent line and the iris plane is taken as the sclera angle (see Figure 3 ), the scleral angle range of a normal human eye is approximately 31.4°–44.6°, and the scleral angle range of a keratoconic eye is approximately 29.8°–46.7°. In this case, by configuring the included angle α to be 28° to 50°, the arc curve can be adapted to the scleral angle of most human eyes. As long as the included angle α is roughly consistent with the scleral angle of the target human eye (for example, the difference between the two does not exceed 1°), the arc curve can be adapted to the scleral angle of the target human eye, thereby achieving the purpose of reducing the pressure of the landing area 60 of the scleral lens 1 on the conjunctival blood vessels during wear, thereby improving the wearing effect, safety, and comfort of the scleral lens 1.

[0055] In some examples, the angle α can be 28°, 29°, 30°, 31°, 31.4°, 32°, 35°, 36°, 38°, 40°, 41°, 42°, 44°, 45°, 46°, 48°, 49°, or 50°.

[0056] In some examples, the included angle α can be adjusted such that when the user wears the scleral lens 1, the scleral lens 1 contacts the sclera 92 of the user at the central position of the arc curve. In this case, when worn, the center of the landing zone 60 contacts the sclera 92, which is beneficial to improving the wearing stability of the scleral lens 1. Additionally, when the user is performing strenuous exercise, even if the scleral lens 1 vibrates / slides inside the eye, since the landing zone 60 tilts outward and the inner surface 20 is spherical, it can inhibit friction between the lens edge and the surface of the eyeball 9 and can reduce the damage caused to the surface of the eyeball 9. Therefore, the scleral lens 1 of the present disclosure can be a night-use scleral lens 1. When the user wears the glasses and performs strenuous exercise at night, even if the scleral lens 1 vibrates with the user's movements, it will not harm the eyeball 9.

[0057] It should be noted that when wearing the scleral lens 1, the landing zone 60 actually contacts the bulbar conjunctiva (the bulbar conjunctiva has no structure and follows the shape of the sclera 92) on the surface of the sclera 92. Since the bulbar conjunctiva covering the sclera 92 is loose connective tissue, after the landing zone 60 contacts the sclera 92 for a period of time (such as 1 h later), the lens will settle, that is, under the pressure of the lens, the bulbar conjunctiva forms a slightly concave shape (see Figure 5A and Figure 5B , Figure 5A is a schematic diagram of the contact between the landing zone 60 and the sclera 92 before the lens settlement occurs, Figure 5B is a schematic diagram of the contact between the landing zone 60 and the sclera 92 after the lens settlement occurs). When settlement occurs, the situation where the central position of the arc curve is within this concave shape also belongs to the description that the central position of the arc curve contacts the sclera 92 of the user. Through the design of the landing zone 60 of the present disclosure, the pressure on the sclera 92 can be evenly distributed, thereby alleviating the occurrence of conjunctival staining, conjunctival leukoplakia, lens adhesion, neovascularization, etc.

[0058] In some examples, the scleral angle of the eyeball 9 can be obtained through corneal topography, and the degree of the included angle α can be adjusted according to the scleral angle. Specifically, the scleral angle at the landing chord corresponding to the required lens size can be measured, and the degree of the included angle α can be adjusted according to the scleral angle. Thereby, an arc curve adapted to the eyeball 9 can be obtained, thus improving the wearing effect and comfort of the scleral lens 1. It should be noted that in the most ideal state, the degree of the included angle α is equal to the scleral angle of the eyeball 9. At this time, the obtained arc curve has the highest degree of adaptation to the sclera 92 of the eyeball 9. However, since the actual shape of the sclera 92 is only in a state close to the tangent, and is not a completely regular tangent state, the scleral angle measured by treating the sclera 92 as a tangent state actually has a slight difference from the actual scleral state. In this case, even if the degree of the included angle α has a difference from the actual scleral state, through the design of the landing zone 60 of the present disclosure being an arc curve, the scleral lens 1 can still have a good adaptation effect with the eyeball 9.

[0059] In some examples, preferably, the difference between the included angle α and the scleral angle of the eyeball 9 can be in the range of -0.5° to 4°. Within this range, the landing area 60 can be further adapted to the sclera 92 of the eyeball 9, thereby ensuring the wearing effect and comfort.

[0060] In some examples, the radial distance d at both ends of the arc curve can satisfy: 1.3 mm ≤ d ≤ 1.7 mm, and the arch height c of the arc curve can satisfy: 0.020 mm ≤ c ≤ 0.075 mm. When worn, if the upturned angle of the landing area 60 is too high, it may reduce the comfort of wearing the scleral lens 1, while if the upturned angle is too low, it is likely to adhere to the sclera 92. In this case, through the radial distance d and arch height c within this range, the height at which the scleral lens 1 upturns outward can be within a certain range, which can reduce the discomfort / foreign body sensation caused by the upturned edge of the lens during wearing, thereby improving the comfort during wearing, and is also beneficial to reducing the generation of bubbles under the lens.

[0061] In some examples, preferably, the radial distance d at both ends of the arc curve can satisfy: 1.4 mm ≤ d ≤ 1.6 mm. For example, the radial distance d at both ends of the arc curve can be 1.4 mm, 1.5 mm, or 1.6 mm.

[0062] In some examples, preferably, the arch height c of the arc curve can satisfy: 0.025 mm ≤ c ≤ 0.075 mm. For example, the arch height c of the arc curve can be 0.025 mm, 0.03 mm, 0.035 mm, 0.04 mm, 0.045 mm, 0.05 mm, 0.055 mm, 0.06 mm, 0.065 mm, 0.07 mm, or 0.075 mm.

[0063] After the included angle α, the radial distance d, and the arch height c are set as above, the landing area 60 of the scleral lens 1 has a fixed shape, and this area is not restricted by other areas of the scleral lens 1. According to the inventor's research, based on the concept of the above specific landing area 60 of the present invention, the scleral lens 1 with the included angle α, the radial distance d, and the arch height c within this numerical range is particularly suitable for the eyeball structure of Asian eyes.

[0064] In some examples, the radius r of the arc curve can satisfy: 4.1 mm ≤ r ≤ 31.1 mm. In this case, the radial distance d and the arch height c at both ends of the arc curve are within a certain range, which can be beneficial to reducing the discomfort / foreign body sensation caused by the upturned edge of the lens during wearing, thereby improving the comfort during wearing.

[0065] In some examples, preferably, the radius r of the arc curve can be 4.23 mm to 30.99 mm. For example, the radius r of the arc curve can be 4.23 mm, 8 mm, 15 mm, 18 mm, 20 mm, 21 mm, 23 mm, 25 mm, 28 mm, or 30.99 mm.

[0066] In some examples, the central angle θ of the arc curve can satisfy the following: 4.4° ≤ θ ≤ 22°. In this case, the radial distance d and the arch height c between the two ends of the arc curve are within a certain range, which can help alleviate the discomfort / foreign body sensation caused by the warping of the lens edge during wear, thereby improving wearing comfort.

[0067] In some examples, preferably, the central angle θ of the arc curve can be 4.60° to 21.62°. For example, the central angle θ of the arc curve can be 4.60°, 6°, 8°, 9°, 11°, 14°, 15°, 17°, 18°, 21°, or 21.62°.

[0068] In some examples, the distance between the center of the scleral lens 1 and the center of the landing zone 60 in the radial direction of the scleral lens 1 can be 6.3 mm to 8.3 mm. In this case, the position of the landing zone 60 of the scleral lens 1 can be adapted to the size of the sclera 92 of most human eyes.

[0069] In some examples, the sagittal distance between the two ends of the arc curve can be 0.74 mm to 1.91 mm. In this case, the outward tilt height of the landing zone 60 of the scleral lens 1 can be within a certain range, which can help alleviate the discomfort / foreign body sensation caused by the tilted lens edge during wear, thereby improving wearer comfort. For example, the sagittal distance between the two ends of the arc curve can be 0.74 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.2 mm, 1.5 mm, 1.6 mm, 1.8 mm, or 1.91 mm.

[0070] It should be noted that although the various parameters related to the arc curve and various parameters of the scleral lens 1 are described in the above content, the above data are parameters that match most human eyes. When the scleral lens 1 of the present disclosure needs to be applied to other scenarios, such as animal eyes 9, users with eye diseases, etc., the above parameters can be appropriately fine-tuned to meet the calculation formula of the arc curve.

[0071] In some examples, the landing zone 60 has non-rotational symmetry. In this case, a scleral lens 1 with regional specificity can be formed. Non-rotational symmetry refers to a quadrant-specific design. The morphology of the sclera 92 of the human eye also varies in different quadrants. For example, the closer to the periphery, the more obvious the asymmetry between the cornea 91 and the sclera 92; therefore, by setting the landing zone 60 to have non-rotational symmetry, the landing zone 60 has different included angles α, vault heights c, and / or radial distances d at least in two meridian directions, so that the landing zone 60 in each quadrant can match the morphology of the sclera 92 in the corresponding quadrant, thereby further improving the overall matching degree of the scleral lens 1 with the eyeball 9 and enhancing the wearing stability and comfort.

[0072] In some examples, the non-rotational symmetry of the landing zone 60 can be designed based on the morphology of the sclera 92 of the eyeball 9. In other words, the quadrant-specific design of the landing zone 60 is based on the morphology of the sclera 92 of the eyeball 9 in each quadrant. Thus, it can better conform to the physiological structure of the eyeball 9, so that it can better match the eyeball 9 and is conducive to evenly distributing the pressure of the scleral lens 1 on the eyeball 9.

[0073] In some examples, quadrant-specific design can be performed on the landing zones 60 on two meridians of the scleral lens 1. Thus, the matching degree of the scleral lens 1 with the eyeball 9 can be further improved, and the wearing stability and comfort can be enhanced. Specifically, the inner surface 20 of the scleral lens 1 can include a first quadrant and a second quadrant. That is, the inner surface 20 is divided into the first quadrant and the second quadrant.

[0074] Specifically, the landing zone 60 in the first quadrant of the inner surface 20 can be designed based on the morphology of the eyeball 9 on the far nasal side, and the landing zone 60 in the second quadrant can be designed based on the morphology of the eyeball 9 on the near nasal side. In other words, the landing zone 60 in the first quadrant of the inner surface 20 can match the far nasal side of the eyeball 9, and the landing zone 60 in the second quadrant can match the near nasal side of the eyeball 9. Among them, the far nasal side can be the side of the eyeball 9 close to the temple, and the near nasal side can be the side of the eyeball 9 close to the nose (far from the temple).

[0075] In some other examples, the optical zone 30 and the mid-peripheral zone 40 in the first quadrant of the inner surface 20 can also be designed based on the morphology of the eyeball 9 on the far nasal side, and the optical zone 30 and the mid-peripheral zone 40 in the second quadrant can also be designed based on the morphology of the eyeball 9 on the near nasal side. In other words, the optical zone 30 and the mid-peripheral zone 40 in the first quadrant of the inner surface 20 can also match the far nasal side of the eyeball 9, and the optical zone 30 and the mid-peripheral zone 40 in the second quadrant can also match the near nasal side of the eyeball 9.

[0076] In some examples, the first quadrant of the inner surface 20 can match the upper eyelid side of the eyeball 9, and the second quadrant can match the lower eyelid side of the eyeball 9. Among them, the far nasal side can be the side of the eyeball 9 close to the upper eyelid, and the near nasal side can be the side of the eyeball 9 close to the lower eyelid (far from the upper eyelid).

[0077] In some other examples, quadrant-specific designs can be carried out on the landing areas 60 on the four semi-meridians of the scleral lens 1. Thus, the matching degree between the scleral lens 1 and the eyeball 9 can be further improved, and the wearing stability and comfort can be enhanced.

[0078] Specifically, the scleral lens 1 can also include a third quadrant and a fourth quadrant. That is to say, in some examples, the inner surface 20 can include a first quadrant, a second quadrant, a third quadrant, and a fourth quadrant. Additionally, in some examples, the inner surface 20 can be divided into a first quadrant, a second quadrant, a third quadrant, and a fourth quadrant.

[0079] In some examples, the first quadrant of the inner surface 20 can match the upper side of the eyeball 9, the second quadrant can match the nasal side of the eyeball 9, the third quadrant can match the lower side of the eyeball 9, and the fourth quadrant can match the temporal side of the eyeball 9. Among them, the upper side can be the side of the eyeball 9 close to the superior rectus muscle, the lower side can be the side of the eyeball 9 close to the inferior rectus muscle (far from the superior rectus muscle), the nasal side can be the side of the eyeball 9 close to the medial rectus muscle, and the temporal side can be the side of the eyeball 9 close to the lateral rectus muscle (far from the medial rectus muscle).

[0080] Specifically, the landing area 60 in the first quadrant of the inner surface 20 can be designed based on the shape of the upper-side eyeball 9, the landing area 60 in the second quadrant can be designed based on the shape of the nasal-side eyeball 9, the landing area 60 in the third quadrant of the inner surface 20 can be designed based on the shape of the lower-side eyeball 9, and the landing area 60 in the fourth quadrant of the inner surface 20 can be designed based on the shape of the temporal-side eyeball 9.

[0081] In some examples, the first quadrant of the inner surface 20 can match the superonasal side of the eyeball 9, the second quadrant can match the inferonasal side of the eyeball 9, the third quadrant can match the inferotemporal side of the eyeball 9, and the fourth quadrant can match the superotemporal side of the eyeball 9. Among them, the superonasal side can be the side of the eyeball 9 close to the superior rectus muscle and the medial rectus muscle, the inferonasal side can be the side of the eyeball 9 close to the medial rectus muscle and the inferior rectus muscle, the superotemporal side can be the side of the eyeball 9 close to the lateral rectus muscle and the superior rectus muscle, and the inferotemporal side can be the side of the eyeball 9 close to the lateral rectus muscle and the inferior rectus muscle.

[0082] Specifically, the landing area 60 in the first quadrant of the inner surface 20 can be designed based on the morphology of the eyeball 9 on the upper nasal side, the landing area 60 in the second quadrant can be designed based on the morphology of the eyeball 9 on the lower nasal side, the landing area 60 in the third quadrant of the inner surface 20 can be designed based on the morphology of the eyeball 9 on the lower temporal side, and the landing area 60 in the fourth quadrant of the inner surface 20 can be designed based on the morphology of the eyeball 9 on the upper temporal side.

[0083] In some other examples, the optical zone 30 and the mid-peripheral zone 40 in each quadrant of the inner surface 20 can also be designed in a quadrant-specific manner.

[0084] In some examples, for the consideration of improving accuracy, the scleral lens 1 as a whole can also be divided into more quadrants to further improve the matching degree with the eyeball 9. For example, the inner surface 20 can also include a fifth quadrant and a sixth quadrant, a seventh quadrant and an eighth quadrant, etc., which are not listed one by one here.

[0085] In some examples, the landing area 60 can also have rotational symmetry. In other words, the landing area 60 may not have quadrant specificity. The corresponding parameters of the landing area 60 are mainly adjusted according to the situation of the eyeball 9.

[0086] Figure 6 Fig. shows a bottom view of the inner surface 20 of the scleral lens 1 involved in the examples of the present disclosure.

[0087] In some examples, as described above, the scleral lens 1 may include an optical zone 30 (see Figure 6 ). The optical zone 30 can be located at the center of the scleral lens 1. That is to say, the optical zone 30 can be the central area of the lens through which external light enters the pupil. In some other examples, the optical zone 30 can provide the effect of correcting vision. In addition, in some examples, the optical zone 30 may not have the function of correcting vision. In this case, the scleral lens 1 can be used to treat corneal 91 diseases.

[0088] In some examples, optionally, the diopter of the optical zone 30 can be adjusted by the sagittal height of the outer surface 10 and / or the inner surface 20. Thus, the needs of various vision correction effects can be met.

[0089] In some examples, the diameter of the optical zone 30 can be determined according to factors such as pupil size, anterior chamber depth, and the thickness of the tear layer between the optical zone 30 and the cornea 91. In addition, in some examples, for the purpose of reducing the impact on vision, preferably, the optical zone 30 can completely cover the pupil. That is to say, the diameter of the optical zone 30 can be the same as or slightly larger than the diameter of the pupil.

[0090] In some examples, the optical zone 30 can match the central region of the cornea 91. In other words, the optical zone 30 can correspond to the central region of the cornea 91. Additionally, in some examples, the elevation of the optical zone 30 can match the depth of the central region of the cornea 91 of the eyeball 9. Thereby, the optical zone 30 can be designed and formed for the central region of the cornea 91, enabling the scleral lens 1 to better match the cornea 91.

[0091] In some examples, when the scleral lens 1 is worn, there can be a gap between the inner surface 20 corresponding to the optical zone 30 and the cornea 91, which helps to form the tear space 8.

[0092] In some examples, the elevation of the optical zone 30 gradually decreases from the center to the edge of the optical zone 30. Thereby, it is beneficial for the concave inner surface 20. In other examples, the amplitude of the decrease in the elevation of the optical zone 30 from the center to the edge of the optical zone 30 increases. Thereby, it is beneficial for forming the concave inner surface 20. Additionally, in some examples, the optical zone 30 can be a curved surface. In other words, the optical zone 30 can be a curved surface formed by a curve. Thereby, it helps to provide an optical effect for correcting vision in the central region.

[0093] In some examples, the gap between the optical zone 30 and the cornea 91 can remain substantially unchanged from the center to the edge of the optical zone 30. In this case, the tear fluid between the lens and the cornea 91 in the optical zone 30 can be evenly distributed, thus providing a better optical correction effect.

[0094] In some examples, the scleral lens 1 can further include a limbal zone 50 formed between the mid-peripheral zone 40 and the landing zone 60 and in a ring shape (see Figure 6 ). The limbal zone 50 can smoothly connect the mid-peripheral zone 40 and the landing zone 60, enabling the inner surface 20 corresponding to the mid-peripheral zone 40 in a sectional shape to smoothly transition to the inner surface 20 corresponding to the landing zone 60 in a spherical shape.

[0095] In some examples, the limbal zone 50 can match the limbus of the cornea 91. In other words, the limbal zone 50 can correspond to the limbus of the cornea 91. Additionally, in some examples, the elevation of the limbal zone 50 can match the depth of the limbus of the cornea 91 of the eyeball 9. Thereby, the limbal zone 50 can be designed for the limbus of the cornea 91, enabling the scleral lens 1 to better match the cornea 91.

[0096] In some examples, the range of the limbus of the cornea 91 can be obtained based on the corneal topography map collected.

[0097] In some examples, when worn, there can be a gap between the limbal zone 50 and the anterior surface of the limbus of the cornea 91. Thereby, it helps to form the tear space 8.

[0098] In some examples, the sagittal height of the limbal region 50 may gradually decrease from the junction of the mid-peripheral region 40 and the limbal region 50 to the junction of the limbal region 50 and the landing region 60.

[0099] In some examples, the limbal region 50 may be a straight surface. In other words, the limbal region 50 may be a curved surface formed by a straight line. That is, in the cross-section of the scleral lens 1 along the sagittal height passing through the center of the scleral lens 1, the limbal region 50 may be formed in a straight line shape. Thereby, it is beneficial for the limbal region 50 to match the cornea 91. That is, the limbal region 50 can better match the limbus of the cornea 91.

[0100] In some examples, optionally, the gap between the limbal region 50 and the cornea 91 may gradually decrease from the junction of the mid-peripheral region 40 and the limbal region 50 to the junction of the limbal region 50 and the landing region 60 (see Figure 1 ). In this case, the tear space 8 can be reduced, so that the amount of tears stored in the tear space 8 can be reduced. Furthermore, both the lens displacement of the scleral lens 1 and the generation of bubbles under the lens can be reduced.

[0101] In some examples, the sagittal height of the limbal region 50 may gradually decrease from the junction of the mid-peripheral region 40 and the limbal region 50 to the junction of the limbal region 50 and the landing region 60 and the decreasing amplitude may decrease.

[0102] In some examples, as described above, the scleral lens 1 may include a mid-peripheral region 40 disposed on the outer periphery of the optical region 30 (see Figure 6 ).

[0103] In some examples, in the longitudinal cross-section along the sagittal height direction of the scleral lens 1, the inner surface 20 of the mid-peripheral region 40 is in a straight line shape. In other words, the inner surface 20 of the mid-peripheral region 40 may be a curved surface formed by a straight line. Thereby, it is beneficial for the mid-peripheral region 40 to match the cornea 91. That is, the mid-peripheral region 40 can better match the peripheral region of the cornea 91.

[0104] In some examples, optionally, the gap between the mid-peripheral region 40 and the cornea 91 gradually decreases from the edge of the optical region 30 to the junction of the limbal region 50 and the landing region 60. In this case, the tear space 8 can be reduced, so that the amount of tears stored in the tear space 8 can be reduced. Furthermore, both the lens displacement of the scleral lens 1 and the generation of bubbles under the lens can be reduced.

[0105] In some examples, the sagittal height of the mid-peripheral region 40 may gradually decrease from the edge of the optical region 30 to the junction of the mid-peripheral region 40 and the limbal region 50 and the decreasing amplitude may increase or decrease.

[0106] In some examples, the shape of the outer surface 10 can be substantially the same as that of the inner surface 20. That is to say, the outer surface 10 of the scleral lens 1 can be designed to be parallel to the inner surface 20. In other examples, the shape of the outer surface 10 can be different from that of the inner surface 20. For example, the outer surface 10 can be a spherical surface or the like. In this case, it is beneficial to improve the wearing comfort of the scleral lens 1.

[0107] In some examples, the thicknesses of the optical zone 30, the mid-peripheral zone 40, the limbal zone 50, and the landing zone 60 can be different. In other examples, the thicknesses of the mid-peripheral zone 40 and the limbal zone 50 can be greater than the thickness of the optical zone 30.

[0108] In some examples, the thickness of the scleral lens 1 can gradually increase from the optical zone 30 to the limbal zone 50. In other words, the thickness of the scleral lens 1 can gradually increase from the center of the optical zone 30 to the outer edge of the limbal zone 50 (the edge away from the connection of the mid-peripheral zone 40 and the limbal zone 50). Thereby, it is beneficial to support the scleral lens 1 to span across the cornea 91.

[0109] In addition, in some examples, the thickness of the landing zone 60 can gradually decrease. That is to say, the thickness of the landing zone 60 can gradually decrease from the connection of the limbal zone 50 and the landing zone 60 to the outer edge of the landing zone 60. Thereby, it is beneficial to improve the wearing comfort of the scleral lens 1.

[0110] In some examples, the thicknesses of the optical zone 30, the mid-peripheral zone 40, and the limbal zone 50 can be substantially the same. In other examples, the thickness of the limbal zone 50 can be greater than the thicknesses of the optical zone 30 and the mid-peripheral zone 40.

[0111] In some examples, the thickness of the optical zone 30 can be from 0.01 mm to 0.1 mm. For example, the thickness of the optical zone 30 can be 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, or 0.1 mm.

[0112] In some examples, the thickness of the mid-peripheral zone 40 can be from 0.05 mm to 0.2 mm. For example, the thickness of the mid-peripheral zone 40 can be 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, or 0.2 mm.

[0113] In some examples, the thickness of the limbal region 50 can be from 0.15 mm to 0.3 mm. For example, the thickness of the limbal region 50 can be 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.2 mm, 0.21 mm, 0.22 mm, 0.23 mm, 0.24 mm, 0.25 mm, 0.26 mm, 0.27 mm, 0.28 mm, 0.29 mm, or 0.3 mm.

[0114] In some examples, the thickness of the landing zone 60 is from 0.01 mm to 0.3 mm. For example, the thickness of the landing zone 60 can be 0.01 mm, 0.03 mm, 0.05 mm, 0.07 mm, 0.1 mm, 0.13 mm, 0.15 mm, 0.17 mm, 0.2 mm, 0.23 mm, 0.25 mm, 0.27 mm, or 0.3 mm. Thus, it is beneficial to improve the wearing comfort of the scleral lens 1.

[0115] In some examples, the ranges of the optical zone 30, the mid-peripheral zone 40, the limbal region 50, and the landing zone 60 can be obtained according to the corneal topographic map of the eyeball 9 collected. Thus, the corresponding dimensions of the scleral lens 1 in which each region is adapted to the eyeball 9 can be obtained, and the adaptability of the scleral lens 1 to the eyeball 9 can be improved.

[0116] In some examples, the scleral lens 1 can be made of a biocompatible material. Additionally, in some examples, the scleral lens 1 can be made of a hydrophilic material. In other examples, the scleral lens 1 can be made of a hydrophobic material.

[0117] In some examples, the scleral lens 1 can be a breathable rigid scleral lens 1. In some examples, the scleral lens 1 can be made of a rigid material. Thus, a rigid scleral lens 1 can be formed. Additionally, in some examples, the scleral lens 1 can be made of a rigid high-oxygen-permeable material. In this case, the scleral lens 1 can have good oxygen permeability, and the abrasion resistance of the scleral lens 1 can be improved and it is beneficial to the production of the scleral lens 1.

[0118] In some examples, the scleral lens 1 can be made of a rigid high-oxygen-permeable material with an oxygen permeability coefficient (DK value) of not less than 100. In other examples, the scleral lens 1 can be made of a rigid high-oxygen-permeable material with an oxygen permeability coefficient of 100 to 200. For example, the oxygen permeability coefficient of the rigid high-oxygen-permeable material can be 100, 125, or 141.

[0119] In some examples, the rigid high-oxygen-permeable material can be selected from at least one of siloxane methacrylate, fluorosiloxane methacrylate, perfluoroether, and fluorinated siloxane.

[0120] In some examples, the center of the scleral lens 1 (e.g., the part including the optical zone 30) can be made of a rigid material, and the periphery of the scleral lens 1 (e.g., the part including the mid-peripheral zone 40 and the landing zone 60) can be made of a soft material. Thus, a hybrid scleral lens 1 can be formed. Additionally, in some examples, only the center of the scleral lens 1 can be made of a rigid high-oxygen-permeable material. In other examples, only the center of the scleral lens 1 can be made of a soft high-oxygen-permeable material.

[0121] In some examples, the material forming the scleral lens 1 can also have anti-precipitation properties. Thus, the ability of the scleral lens 1 surface to resist protein precipitation can be enhanced, thereby extending the lifespan of the scleral lens 1.

[0122] In some examples, the surface of the scleral lens 1 can be processed to increase the hydrophilicity of the scleral lens 1 lens. Thus, the wettability of the scleral lens 1 surface can be improved, thereby improving the wearing comfort. For example, the surface of the scleral lens 1 can be plasma-treated, or a hydrophilic coating can be applied to the surface of the scleral lens 1, etc.

[0123] In some examples, the thickness of the scleral lens 1 can be from 0.2 mm to 1.2 mm. Thus, both the deformation of the scleral lens 1 lens can be alleviated, and the scleral lens 1 can be prevented from being too heavy. For example, the thickness of the scleral lens 1 can be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, or 1.2 mm, etc.

[0124] In the present embodiment, the diameter of the scleral lens 1 can be selected according to the actual situation of the eyeball 9. For example, in some examples, the diameter of the scleral lens 1 can be from 14.5 mm to 16.5 mm. Thus, it can span the cornea 91 and contact the sclera 92. Additionally, the edge of the large-diameter scleral lens 1 can be hidden under the eyelid, thereby reducing the lens sliding caused by eyelid movement. Additionally, in some examples, the diameter of the scleral lens 1 can be 14.5 mm, 15 mm, 15.5 mm, 16 mm, or 16.5 mm.

[0125] In some examples, the oxygen permeability coefficient (DK value) of the scleral lens 1 can be from 100 to 200. Thus, it can have good oxygen permeability, enabling the tear fluid to provide sufficient oxygen to the cornea 91, and further being beneficial to maintaining the health of the cornea 91. For example, the oxygen permeability coefficient of the scleral lens 1 can be 100, 105, 110, 115, 120, 125, 130, 135, 141, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, or 200.

[0126] In some examples, the scleral lens 1 can be applicable to patients with corneal 91 diseases to improve normal corneal 91 function and vision, relieve pain, reduce light sensitivity, etc. In other examples, the scleral lens 1 can be used for refractive correction of irregular corneas 91 and for diseases such as exposure keratitis 91 and severe corneal 91 xerosis.

[0127] In some examples, the scleral lens 1 can be applicable to dry eye, corneal 91 injury, microphthalmia, ocular pemphigus, keratoconus 91, corneal 91 ectasia, Stevens-Johnson syndrome, Sjogren's syndrome, aniridia, neurotrophic keratitis 91, irregular astigmatism, complications after corneal 91 transplantation, distorted corneal 91 implants, etc.

[0128] In some examples, when wearing the scleral lens 1, the scleral lens 1 can be filled with normal saline or therapeutic liquid before wearing. Thereby, the generation of bubbles under the lens can be reduced.

[0129] According to the scleral lens 1 involved in the present disclosure, it can fit well with the sclera 92 during wearing and can evenly disperse the pressure borne by the sclera 92.

[0130] In the second aspect of the present disclosure, a fitting method for a scleral contact lens is directed to the fitting method for the scleral contact lens involved in the first aspect of the present disclosure. In the present disclosure, the fitting method for the scleral contact lens can be abbreviated as the "first fitting method".

[0131] Hereinafter, with reference to the drawings, the first fitting method involved in the second aspect of the present disclosure will be described.

[0132] Figure 7 It is a flowchart showing the first fitting method involved in the examples of the present disclosure.

[0133] In this embodiment, referring to Figure 7 , the first fitting method may include the following steps: presetting the included angle α to 36° to select a preset scleral lens 1 (step 1); after coloring at least one mark on the outer edge of the inner surface 20 or the outer surface 10 of the scleral lens 1, trying it on the user (step 2); enabling the user to blink at a frequency of 2 times / second to 5 times / second for at least 3 times, and observing whether the scleral lens 1 rotates by observing the mark (step 3); when the scleral lens 1 does not rotate, reducing the included angle α in steps of 1° or 2° to select a new scleral lens 1, and then repeating steps 2 to S40; when the scleral lens 1 rotates and the position of the scleral lens 1 is different after each blink, increasing the included angle α in steps of 1° or 2° to select a new scleral lens 1, and then repeating steps 2 to S40; when the scleral lens 1 rotates and the positions of the marks on the scleral lens 1 are basically the same after at least two blinks, determining the parameters of the scleral lens 1 to complete the fitting (step 4).

[0134] In the first spectacle fitting method related to the second aspect of the present disclosure, since the scleral angle of the average human eye is in the range of 31.4°–44.6°, by presetting the included angle α of the scleral lens 1 in its initial form to 36° in step 1, it is beneficial to reduce the number of times the degree of the included angle α needs to be adjusted in subsequent steps and improve the fitting efficiency; in step 2, by adding marks on the lens, it is convenient to observe the rotation amplitude of the lens in subsequent steps; in steps 3 and 4, the matching degree (i.e., the tightness degree) between the scleral lens 1 and the eyeball 9 is judged by observing the rotation amplitude of the lens, and appropriate adjustments are made according to the actual situation; when the positions of the marks on the scleral lens 1 are basically the same after the blink ends, that is, when the included angle α of the scleral lens 1 is basically the same as the scleral angle of the eyeball 9, the parameters of the scleral lens 1 with a moderate tightness degree matching the eyeball 9 can be obtained, and the fitting is completed; in addition, the first spectacle fitting method of the present disclosure is also helpful for fitting the scleral lens 1 to the irregular cornea 91, and can also solve problems such as inaccurate curvature caused by damage to the cornea 91 to a certain extent.

[0135] When wearing the scleral lens 1, if the landing zone 60 of the scleral lens 1 has a high matching degree with the eyeball 9 and a moderate tightness degree, after the user blinks, the scleral lens 1 will rotate with a small amplitude (the small rotation may reset after blinking again, so it does not affect the use of the scleral lens 1), and there will be no large rotation / deviation, nor will there be a situation of not rotating at all.

[0136] Therefore, in step 4, when it is observed that the scleral lens 1 does not rotate, it means that the scleral lens 1 is too tight relative to the eyeball 9, and the landing zone 60 overly compresses the sclera 92. At this time, by reducing the included angle α, a flatter landing zone 60 can be obtained, thereby reducing the compression of the landing zone 60 on the sclera 92 until the landing zone 60 matches the sclera 92.

[0137] In step 4, when it is observed that the scleral lens 1 rotates with a large amplitude, it means that the scleral lens 1 is too loose relative to the eyeball 9, and the fitting degree between the landing zone 60 and the sclera 92 is not high. At this time, by increasing the included angle α, a steeper landing zone 60 can be obtained, thereby increasing the fitting degree between the landing zone 60 and the sclera 92 until the landing zone 60 matches the sclera 92.

[0138] In some examples, in step 4, the situation where the scleral lens 1 does not rotate or rotates greatly may also be due to an incorrect wearing position of the scleral lens 1 during wearing. Specifically, in the scleral lens 1 of the present disclosure, the inner surface 20 of the landing zone 60 may have non-rotational symmetry, that is, the inner surface 20 of the landing zone 60 may have different forms in each quadrant (for example, different included angles α, vault heights c, and / or radial distances d). At this time, if the scleral lens 1 is not worn in accordance with the preset meridian direction, the above situation may also occur.

[0139] In some examples, in step 3, the time interval between two adjacent blinks can be set between 0.5 seconds and 2 seconds. In this case, since the average person blinks about 10 - 20 times per minute, when wearing a scleral lens, a foreign body sensation may cause an increase in the blinking frequency. At this time, by setting the time interval between two adjacent blinks between 0.5 seconds and 2 seconds, it is possible to simulate the situation where the lens rotates / displaces under the conditions of daily wearing of the scleral lens and / or frequent use of the eyes, so as to further obtain the parameters of the scleral lens 1 adapted to the eyeball 9. For example, in step 3, the time interval between two adjacent blinks can be 0.5 seconds, 0.8 seconds, 1 second, 1.5 seconds, 1.8 seconds, or 2 seconds, etc.

[0140] In some examples, in step 3, the next blink can be performed after the scleral lens 1 stops rotating. In this case, it is convenient to observe the actual rotation amplitude of the scleral lens 1, so as to further obtain the parameters of the scleral lens 1 adapted to the eyeball 9.

[0141] According to the first spectacle fitting method related to the second aspect of the present disclosure, it is possible to obtain the parameters of the scleral lens 1 with a moderate tightness degree matching the eyeball 9, so that the scleral lens 1 suitable for the user can be configured according to the parameters.

[0142] In the third aspect of the present disclosure, a spectacle fitting method for the scleral lens 1 is directed to the spectacle fitting method for the scleral lens 1 related to the first aspect of the present disclosure. In the present disclosure, the spectacle fitting method for the scleral lens 1 can be abbreviated as the "second spectacle fitting method".

[0143] Hereinafter, with reference to the drawings, the second spectacle fitting method related to the third aspect of the present disclosure will be described.

[0144] Figure 8 It is a flowchart showing the second spectacle fitting method involved in the examples of the present disclosure.

[0145] In this embodiment, refer to Figure 8, the second fitting method may include the following steps: preset the included angle α to 36° to select the scleral lens 1 in its initial form (step 10); try on the scleral lens 1 on the user (step 20); after waiting for a predetermined time, observe under a slit lamp whether any one of the following phenomena occurs at the edge of the user's sclera 92 corresponding to the scleral lens 1: a significant change in blood vessel diameter, blood vessel cutoff, a circular white and shiny sclera 92, or a circular black shadow (step 30); when any one of the phenomena of a significant change in blood vessel diameter, blood vessel cutoff, or a circular white and shiny sclera 92 occurs, reduce the included angle α by at least 1° to select a new scleral lens 1, and then repeat steps 20 to 40; when a circular black shadow appears, increase the included angle α by 1° or 2° to select a new scleral lens 1, and then repeat steps 20 to 40; when none of the phenomena of a significant change in blood vessel diameter, blood vessel cutoff, a circular white and shiny sclera 92, or a circular black shadow is found, determine the parameters of the scleral lens 1 to complete the fitting (step 40).

[0146] In the second fitting method related to the third aspect of the present disclosure, since the scleral angle of the average human eye is in the range of 31.4° - 44.6°, by presetting the included angle α of the scleral lens 1 in its initial form to 36° in step 10, it is beneficial to reduce the number of times the degree of the included angle α needs to be adjusted in subsequent steps and improve the fitting efficiency; in steps 30 and 40, the condition of the user's sclera 92 can be clearly observed through a slit lamp, and the degree of the included angle α is adjusted based on the condition of the sclera 92. When the sclera 92 shows no abnormality after adjustment, the parameters of the scleral lens 1 with a moderate tightness matching the eyeball 9 can be obtained to complete the fitting. At this time, the included angle α of the scleral lens 1 is basically the same as the scleral angle of the eyeball 9. In addition, the second fitting method of the present disclosure is also helpful for fitting the scleral lens 1 for an irregular cornea 91 and can also alleviate problems such as inaccurate curvature caused by corneal 91 damage.

[0147] In some examples, in step 30, the predetermined time may be not less than 1 hour. Thus, the wearing effect of the scleral lens 1 fully settling on the sclera 92 during daily wearing can be simulated, so as to obtain parameters of the scleral lens 1 that are further adapted to the eyeball 9.

[0148] Figure 9 is a schematic diagram showing various scleral states under a slit lamp related to the examples of the present disclosure. It should be noted that the respective adapted states shown in this figure have a corresponding relationship with the landing area 60 of the scleral lens 1 according to the present invention. When wearing a scleral lens 1 with a landing area 60 of other forms and the Figure 9 various states shown occur, Figure 9 it does not indicate that the scleral lens 1 with a landing area 60 of other forms has corresponding tightness or looseness problems.

[0149] In some examples, in step 40, when any one of the phenomena of significant change in blood vessel diameter, blood vessel interruption, or a circular white and shiny sclera 92 occurs, it indicates that the scleral lens 1 is too tight relative to the eyeball 9, and the landing area 60 excessively compresses the sclera 92, resulting in the blood vessels on the sclera 92 being compressed at the edge of the scleral lens 1, showing a decrease in blood vessel diameter and / or blood vessel interruption. At this time, by reducing the angle α, a flatter landing area 60 can be obtained, thereby reducing the compression of the landing area 60 on the sclera 92 until it is adjusted to match the sclera 92 with the landing area 60.

[0150] In some examples, as Figure 9 shown, state 1 is an example of a significant change (narrowing) in blood vessel diameter; state 2 is an example of a circular white and shiny sclera 92; state 3 is an example of blood vessel interruption and a circular white and shiny appearance, and at this time, the circumferential sclera 92 is subjected to a strong compressive force.

[0151] In some examples, in step 40, when a significant change in blood vessel diameter occurs, the angle α can be reduced in steps of 1° or 2° to select a new scleral lens 1, and then steps 20 to 40 are repeated; and / or when blood vessel interruption is found, the angle α is reduced in steps of 3° or 4° to select a new scleral lens 1, and then steps 20 to 40 are repeated; and / or when a circular white and shiny sclera 92 is found, the angle α is reduced in steps of 5° or 6° to select a new scleral lens 1, and then steps 20 to 40 are repeated. In this case, the reduction step of the angle α can be adaptively adjusted according to the sclera 92 conditions of different severities, thereby improving the fitting efficiency.

[0152] In step 40, when a circular black shadow appears, it indicates that the scleral lens 1 is too loose relative to the eyeball 9, and the fitting degree between the landing area 60 and the sclera 92 is not high. At this time, by increasing the angle α, a steeper landing area 60 can be obtained, thereby increasing the fitting degree between the landing area 60 and the sclera 92 until it is adjusted to match the sclera 92 with the landing area 60. It should be noted that the circular black shadow actually appears on the sclera 92. Since the scleral lens 1 is too loose, the scleral lens 1 is "floating" on the surface of the eyeball 9 as a whole, and a black shadow is formed on the sclera 92 under the action of external light.

[0153] As Figure 9 shown, state 4 is an example of a circular black shadow appearing, and at this time, the fitting degree between the landing area 60 and the sclera 92 is not high.

[0154] According to the second spectacle fitting method related to the third aspect of the present disclosure, parameters of the scleral lens 1 with a moderate tightness degree matching the eyeball 9 can be obtained, so that the scleral lens 1 suitable for the user can be configured according to the parameters. It should be noted that although the present disclosure provides two spectacle fitting methods, the landing area 60 in the scleral lens 1 related to the first aspect of the present invention is designed with an inverse circular arc and has good adaptability to scleras 92 of various shapes, which can simplify the spectacle fitting process. And through the two spectacle fitting methods provided by the present disclosure, the scleral lens 1 can be further adjusted to make its tightness degree and the circular arc surface of the landing area 60 more adaptable to the eyeball 9, which does not mean that the scleral lens 1 of the present disclosure can only be spectacle-fitted according to the above two spectacle fitting methods.

[0155] In summary, according to the scleral lens 1 of the present disclosure, it is sufficient to ensure that the spectacle fitter can quickly spectacle-fit a scleral lens 1 for the patient, which has good matching with the sclera 92 and can evenly disperse the pressure borne by the sclera 92 and has high wearing comfort. In addition, according to the spectacle fitting method of the present disclosure, the spectacle fitter can quickly spectacle-fit the adaptability effect of the scleral lens 1.

[0156] Although the present disclosure has been specifically described above in combination with the drawings and embodiments, it can be understood that the above description does not limit the present disclosure in any form. Those skilled in the art can deform and change the present disclosure according to needs without departing from the essence and scope of the present disclosure, and these deformations and changes all fall within the scope of the present disclosure.

Claims

1. A scleral contact lens, characterized in that, The scleral contact lens includes an optical zone formed successively from the inside outwards, a mid-peripheral zone surrounding the outer periphery of the optical zone, and a landing zone surrounding the outer periphery of the mid-peripheral zone. When the scleral contact lens is worn, a tear lens for accommodating tears to correct vision is formed between the optical zone and the cornea. The inner surface of the landing zone contacts the sclera. In a longitudinal section along the sagittal height direction of the scleral contact lens, the inner surface of the landing zone is an arc curve with the center of the circle located on the outer surface side of the scleral contact lens, and the arc curve satisfies: Wherein, r is the radius of the arc curve, c is the arch height of the arc curve, d is the radial distance between the two ends of the arc curve in the radial direction of the scleral contact lens, and α is the angle between the straight line segment defined by the two ends of the arc curve and the radial direction of the scleral contact lens, and the angle α satisfies: 28° ≤ α ≤ 50°.

2. The scleral contact lens according to claim 1, characterized in that, The radial distance d between the two ends of the arc curve satisfies: 1.3 mm ≤ d ≤ 1.7 mm, and the arch height c of the arc curve satisfies: 0.020 mm ≤ c ≤ 0.075 mm.

3. The scleral contact lens according to claim 1, wherein The radius r of the arc curve satisfies: 4.1 mm ≤ r ≤ 31.1 mm.

4. The scleral contact lens according to claim 1, characterized in that, The central angle θ of the arc curve satisfies: 4.4° ≤ θ ≤ 22°.

5. The scleral contact lens according to any one of claims 1-4, characterized in that, The distance between the center of the scleral contact lens and the center of the landing zone in the radial direction of the scleral contact lens is 6.3 mm to 8.3 mm.

6. The scleral contact lens according to any one of claims 1-5, characterized in that, The landing zone is non-rotationally symmetric.

7. The scleral contact lens according to claim 1, wherein In a longitudinal section along the sagittal height direction of the scleral contact lens, the inner surface of the mid-peripheral zone is linear.

8. The scleral contact lens according to claim 1, wherein It further includes a limbal zone formed between the mid-peripheral zone and the landing zone and in a ring shape.

9. The scleral contact lens according to claim 8, wherein The radius of curvature of the inner surface of the limbal zone is greater than the radius of curvature of the inner surface of the landing zone.

10. The scleral contact lens according to claim 6, characterized in that, Adjust the angle α so that when the user wears the scleral contact lens, the scleral contact lens contacts the user's sclera at the central position of the arc curve.

11. A method for fitting a scleral contact lens according to any one of claims 1-10, characterized in that, The fitting method includes the following steps: Step 1, preset the angle α to 36° to select a preset scleral contact lens; Step 2, after coloring at least one mark on the outer edge of the inner surface or the outer surface of the scleral contact lens, try it on the user; Step 3, let the user blink at a frequency of 2 times / second to 5 times / second for at least 3 times, and observe whether the scleral contact lens rotates by observing the mark; Step 4, when the scleral contact lens does not rotate, reduce the angle α in steps of 1° or 2° to select a new scleral contact lens, and then repeat steps 2 to 4; When the scleral contact lens rotates and the position of the scleral contact lens is different after each blink, increase the angle α in steps of 1° or 2° to select a new scleral contact lens, and then repeat steps 2 to 4; When the scleral contact lens rotates and the position of the mark of the scleral contact lens is basically the same after at least two blinks, determine the parameters of the scleral contact lens to complete the fitting.

12. A spectacle fitting method as claimed in claim 11, characterized in that, The time interval between two adjacent blinks is set between 0.5 seconds and 2 seconds.

13. A spectacle fitting method as described in claim 11, characterized in that, After the scleral contact lens stops rotating, the next blink is performed.

14. A method for fitting a scleral contact lens according to any one of claims 1-10, characterized in that, The spectacle fitting method includes the following steps: Step 10, preset the included angle α to 36° to select the scleral contact lens in the initial form; Step 20, try on the scleral contact lens on the user; Step 30, after waiting for a predetermined time, observe under a slit lamp whether any one of the following phenomena occurs at the edge of the user's sclera corresponding to the scleral contact lens: obvious change in blood vessel diameter, blood vessel interruption, annular white and shiny sclera, or annular black shadow; Step 40, when any one of the phenomena of obvious change in blood vessel diameter, blood vessel interruption, or annular white and shiny sclera occurs, reduce the included angle α by at least 1° to select a new scleral contact lens, and then repeat steps 20 to 40; When an annular black shadow appears, increase the included angle α by 1° or 2° to select a new scleral contact lens, and then repeat steps 20 to 40; When none of the phenomena of obvious change in blood vessel diameter, blood vessel interruption, annular white and shiny sclera, or annular black shadow is found, determine the parameters of the scleral contact lens and complete the fitting.

15. A spectacle fitting method as described in claim 14, characterized in that, The predetermined time is not less than 1 hour.

16. A spectacle fitting method as described in claim 14, characterized in that, When an obvious change in blood vessel diameter occurs, reduce the included angle α by 1° or 2° to select a new scleral contact lens, and then repeat steps 20 to 40; and / or When blood vessel interruption is found, reduce the included angle α by 3° or 4° to select a new scleral contact lens, and then repeat steps 20 to 40; and / or When an annular white and shiny sclera is found, reduce the included angle α by 5° or 6° to select a new scleral contact lens, and then repeat steps 20 to 40.

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