Contact lens structure

Abstract

The present invention relates to a contact lens structure (100) comprising: a housing (110) having a front layer (113) and a rear layer (114), where the front layer determines a rear vertex power of the contact lens structure (100); and an air chamber (120) located within the housing between the front layer (113) and the rear layer (114) of the housing (110). The contact lens structure further comprises a planar assembly (130) disposed at least partially within the air chamber (120) in the optical region (100a) of the contact lens structure (100).

Description

Technical Field

[0001] The present disclosure relates to the field of optics, and more particularly to contact lens structures. Background Art

[0002] Smart contact lenses are contact lenses embedded with electronic components and may also contain other materials to increase functionality. It is a known fact that contact lenses need to be oxygen permeable because the cornea is a tissue that is oxygenated by interaction with its environment. Using contact lenses that are not sufficiently oxygen permeable may cause corneal edema, resulting in symptoms such as irritation, blurred vision, and redness of the eyes.

[0003] The electronic components and materials embedded in smart contact lenses are typically not permeable to oxygen. When these smart components occupy a relatively large surface area, conventional contact lenses embedded with these components cannot provide sufficient oxygen permeability and cannot be used by patients.

[0004] Further, electronic components in smart contact lenses are typically small and are donut-shaped or curved to mimic the shape of conventional contact lenses so that these components can fit into typical spherical contact lens designs. When large planar components are introduced into contact lenses, the approach of embedding the platform in a rigid gas permeable (RGP) material using the shape of a conventional lens does not work because the resulting contact lens is too thick and heavy for patient comfort and significantly reduces the oxygen permeability of the lens.

[0005] Some other methods have been disclosed to increase the oxygen permeability of smart contact lenses or scleral lenses. Patent document US9039171 B2 introduces a contact lens assembly, which includes a proximal layer formed of a gas permeable material, a distal layer having an optical element, an air cavity arranged between the proximal layer and the distal layer, and a gas delivery area surrounding the air cavity. In patent document US10095051 B2, the method adopted is to provide an air shaft passing through the non-permeable core of the contact lens, thereby directly connecting the environment with the tear fluid between the scleral lens and the cornea. Patent document EP 3893045 A2 provides a scleral lens having a plurality of annularly distributed openings in its optical zone, and having two or more bags in a bag annular zone on the rear surface of the optical zone. Another method is the method adopted in patent document US 8087777, in which a microchamber is arranged in the optical zone in the rear surface of the scleral lens. In patent document WO 2020097205A1, an impermeable core surrounding a contact lens is provided with an outer air cavity and an inner air cavity, and an air path is provided through the core to connect the two cavities. Finally, in patent document US 9869884 B2, water transmission rate maximization and oxygen permeability minimization are achieved by a single lens material of a predetermined lens thickness or by using two or more material layers.

[0006] Therefore, there is a need for a contact lens structure that can be used in a smart platform while allowing sufficient oxygen permeability and desired optical properties. Summary of the invention

[0007] The present disclosure addresses the shortcomings of existing solutions through a contact lens structure that embeds a planar component while maintaining oxygen permeability.

[0008] The invention is defined by the accompanying independent claims, embodiments are set forth in the accompanying dependent claims, in the following description and in the drawings.

[0009] According to a first aspect of the present invention, there is provided a contact lens structure, the contact lens structure comprising: a housing having a front layer and a rear layer, wherein a rear vertex power of the contact lens structure is generated by the optical power of the front layer and the rear layer; and an air chamber, the air chamber being completely located within the housing, between the front layer and the rear layer of the housing. The contact lens structure further comprises a planar component, the planar component being at least partially arranged within the air chamber, in an optical zone of the contact lens structure.

[0010] The contact lens structure is embedded with a planar component (such as a planar component of a smart contact lens) while still making the patient feel comfortable and maintaining oxygen permeability. The planar component can be a basic planar component. A planar component can refer to a component having a substantially flat extension in one plane. The planar component can have a top surface and a bottom surface, and these surfaces can be parallel to at least a large portion (>50%) of the extension of the planar component, or at least 70%, at least 80%, at least 90% or 100% of the extensions of the two surfaces can be parallel. The planar component, which is typically large and centrally positioned within the contact lens structure, can be housed in an air chamber, which typically can at least cover the optical zone of the contact lens structure and allow air to flow adjacent to the planar component. The planar component can also interface with the front layer. The planar component can be a planar electronic component.

[0011] The ability to embed a planar component can provide the functionality of a smart contact lens that houses the component. Embedding a planar component within a contact lens structure can be advantageous because its manufacturability is simplified. It is easier to manufacture a planar component than a curved component. Further, a planar component may not have to be customized for a specific person.

[0012] The planar component can be generally centrally positioned within the air chamber and within the optical zone of the contact lens structure. The presence of a large central planar component in the contact lens structure would impede oxygen flow if there were not an air chamber that allowed oxygen to flow therein along the planar component. The planar component can be a substantially planar component. The oxygen present in the air chamber can be distributed in a uniform manner over an extension of the air chamber. Thus, the oxygen can reach the user's eyes via the air chamber and through the air permeable rear layer over the entire optical zone. Oxygen can enter the air chamber from the environment through the air permeable front layer at a location outside the optical zone. The air chamber can then evenly distribute the oxygen over the entire optical zone, through the rear layer, to the eye.

[0013] Being arranged at least partially in the air chamber may mean that the planar component may be arranged to the rear surface of the front layer, thereby partially extending into the air chamber. Thus, the planar component may be arranged at the interface between the front layer and the air chamber.

[0014] The rear layer may have a rear surface that is curved substantially to follow the shape of the human eye. When used on a human eye, the rear surface may face the eye. The rear layer may have an optical power that is attributed to the optical power of the contact lens structure.

[0015] The front layer can be understood as the portion of the housing that is included within the outermost surface of the housing and the front surface of the air chamber. The front layer can include or be made of a contact lens material. The front layer can have an optical power that is attributed to the optical power of the contact lens structure and, in turn, to the optical power of the smart contact lens that includes such a contact lens structure.

[0016] The manner in which the optical power of the contact lens structure is provided or the manner in which the back vertex power is determined in the present invention can allow for greater flexibility in defining the radius of curvature of components in the optical zone, which can be used to reduce the mass and center thickness of the contact lens structure, thereby increasing patient comfort. In general, the radius of curvature of the front surface of the proposed contact lens structure can be significantly larger than the front radius of curvature typically encountered in contact lenses. This can be due to the enclosing of an air chamber in the housing.

[0017] In some embodiments, the front layer may include a front surface that includes at least a planar portion or a substantially planar portion. The planar portion of the front surface of the housing may allow a substantially planar component to be placed within the air chamber, adjacent to or even attached to the (substantially) planar portion. Furthermore, such a configuration in which the planar component is arranged at the outermost position within the air chamber may be advantageous because the gross weight and material of the contact lens structure may be reduced. The presence of the air chamber may provide that only a small curvature (i.e., a large radius of curvature) is required to achieve the desired refractive properties of the lens. Thus, the weight reduction may be a result of the presence of the air chamber and the small volume of the front layer of the housing due to the small curvature of the front surface.

[0018] The diameter of the planar portion may be 5 mm to 9 mm. In some embodiments, the planar portion may extend over substantially the entire planar component.

[0019] The optical power or back vertex power of the contact lens structure may be provided by the front and back layers of the housing, particularly by a planar or substantially planar portion of the front surface.

[0020] In some embodiments, the radius of curvature of the planar portion of the front surface can be at least twice the radius of curvature of the front surface of a standard contact lens. That is, the radius of curvature of the substantially planar portion is much greater than the radius of curvature of the outermost surface of any standard contact lens, the latter radius of curvature can be in the range of 6 mm to 10 mm. In some embodiments, the absolute value of the radius of curvature of the substantially planar portion can be greater than 20 mm. The radius of curvature of the substantially planar portion can be greater than the radius of curvature of other portions of the front surface. Such other portions can be portions radially outside of the planar portion, and / or zones radially outside of the optical zone of the contact lens structure. Such one or more zones can be transition zones and / or landing zones as further discussed below.

[0021] In some embodiments, the contact lens structure may include a transition zone and / or a landing zone, wherein the transition zone and the landing zone are zones radially outside the optical zone, and wherein the radius of curvature of the planar portion of the front surface may be greater than the radius of curvature of the portion of the front surface at the transition zone and / or the landing zone.

[0022] In some embodiments, the back vertex power of a contact lens structure can depend on the curvature (radius of curvature) of a flat or substantially planar portion.

[0023] In some embodiments, the housing can be made entirely of contact lens material, such as any commercially available contact lens material.

[0024] In some embodiments, the rear layer of the housing may have a rear surface that may be curved substantially following the shape of a human eye. The radius of curvature of the rear surface may be between 6 mm and 10 mm.

[0025] In some embodiments, the air chamber can be centrally located within the housing. This configuration provides symmetry, which is particularly suitable for certain applications of contact lenses.

[0026] In some embodiments, the center thickness of the front layer can be between 100 μm and 800 μm. A front layer having such a thickness range can provide a contact lens structure with a wide range of optical powers by providing the front layer with a certain range of curvature radii at least at the optical zone of the contact lens structure. The thickness of the front layer can be provided at least at the optical zone of the contact lens structure.

[0027] In some embodiments, the air chamber can cover at least the optical zone of the contact lens structure, and in some embodiments can also cover at least a portion of the transition zone of the contact lens structure, thereby improving oxygen permeability. The transition zone can be defined as a zone radially outside of the optical zone of the contact lens structure and adjacent to the optical zone.

[0028] In some embodiments, the air chamber may also cover a portion of the landing zone of the contact lens structure, which may further improve the overall oxygen permeability of the contact lens structure. The landing zone may be defined as a zone radially outside of the optical zone and at the radial ends of the contact lens structure, and / or radially outside of the transition zone of the contact lens structure.

[0029] In some embodiments, the air chamber can be a single air chamber, which can improve oxygen delivery within the contact lens structure. Further, a single air chamber can enable a large planar component, which may be necessary in certain applications, such as when the planar component is an LCD.

[0030] In some embodiments, the size of the air chamber can be determined so that the solid angle covered when viewed from the center of curvature of the back surface is between 0.5*π and 0.9*π, preferably between 0.6*π and 0.8π, and more preferably between 0.65*π and 0.7*π. In this way, it can be ensured that the air chamber covers at least the standard complete cornea of ​​the human eye. It should be taken into account that the standard diameter of the cornea of ​​a male Caucasian is about 11-13 mm and the standard diameter of the cornea of ​​a female Caucasian is about 10.5-12 mm, both for adults. Racial deviations and age can also be taken into account, as the standard diameter for children is smaller. The solid angle can provide a cone angle that defines the extension of the curvature of the air chamber along the contact lens structure.

[0031] In some embodiments, the contact lens structure may include a permeable zone of the front layer. The permeable zone may be formed as a portion of the front layer outside the planar assembly and adjacent to the air chamber. At the permeable zone, oxygen can be transported to the air chamber through the air-permeable front layer. The permeable zone may be substantially located outside the optical zone. In the radial direction, the permeable zone may end where the air chamber ends. The permeable zone may be located outside the portion of the front layer covering the planar assembly. The permeable zone may be arranged adjacent to the optical zone. In some embodiments, the permeable zone may extend from the radial end of the planar assembly at the front layer along the radial extension of the air chamber.

[0032] In some embodiments, the contact lens structure includes a component platform, which includes a planar component. The component platform may further include an annular component portion extending radially outward from the planar component. The component platform may include at least one opening between the annular component portion and the planar component. The opening in the component platform may form a permeability zone of the front layer, and oxygen may be transported to the air chamber through the permeability zone. Similar to the planar component, the annular portion may be arranged in the air chamber, adjacent to the front layer. The component platform may have a radial extension corresponding to the radial extension of the air chamber. For the component platform, the permeability zone may extend from the radial end of the planar component to the radial inner edge of the annular component portion at the front surface.

[0033] In some embodiments, the contact lens structure may further include a component platform, which includes a planar component and an annular component arranged radially outside the planar component. At least one opening may be formed between the planar component and the annular component, and oxygen may be configured to pass through the front layer to the air chamber through the at least one opening. The component platform may be airtight. At least one opening between the planar component and the annular component may enable oxygen to pass through the air permeable front layer to the air chamber. The component platform may further include a connecting member extending between the planar component and the annular component. The at least one opening may be formed between the connecting members.

[0034] In some embodiments, the planar component can be arranged at a distance of 20 μm and 200 μm from the rear layer at the center of curvature of the rear surface. The planar component is at least partially arranged in the air chamber, in the optical zone. Further, the planar component can be arranged adjacent to the front layer. Thus, the air chamber extends along the planar component between the planar component and the rear layer. The distance between the planar component (i.e., the surface of the planar component facing the rear layer) and the rear layer (i.e., the surface of the rear layer facing the air chamber) can be between 20 μm and 200 μm. This distance can be located at the center of curvature of the rear surface, thereby providing a minimum distance between the planar component and the rear layer along the extension of the planar component. This distance can pass through the air chamber, and the thickness of the air chamber can be set at the center of curvature of the rear surface.

[0035] The contact lens structure according to any of the embodiments may be applied to RGP, scleral and / or corneal contact lenses.

[0036] The different aspects and embodiments defined above may be combined with each other as long as they are compatible with each other.

[0037] Additional advantages and features of the present disclosure will become apparent from the following detailed description and will be particularly pointed out in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to complete the description and to provide a better understanding of the present disclosure, a set of drawings is provided. The drawings form an integral part of the description and illustrate one or more embodiments, which should not be interpreted as limiting the scope of the present disclosure, but only as examples of how the present disclosure can be implemented. The drawings include the following figures:

[0039] Figure 1 A cross-sectional view of a contact lens structure according to an embodiment of the present invention is shown.

[0040] Figure 2 A cross-sectional view of a contact lens structure according to an embodiment of the present invention is shown.

[0041] Figure 3 A perspective view of an assembly platform according to an embodiment of the present invention is shown.

[0042] Figure 4 A conventional scleral lens is shown schematically.

[0043] Figure 5 The structures of a conventional scleral lens and a contact lens according to an embodiment of the present invention are schematically shown, both of which have a planar component embedded therein.

[0044] Figure 6 A cross-sectional view showing the structure of a contact lens according to an embodiment of the present invention.

[0045] Figure 7 A cross-sectional view of a contact lens structure according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0046] The following description should not be taken in a limiting sense, but is given merely for the purpose of describing the broad principles of the present disclosure.

[0047] The contact lens structure is embedded with relatively large components while maintaining oxygen permeability. The center thickness and total mass of the contact lens structure are significantly less than the center thickness and total mass of a standard contact lens with the same application, thereby making it comfortable for patients to wear. In addition, as will be explained below, the contact lens structure can be shaped so that it provides correction for myopia or hyperopia, astigmatism, and higher-order aberrations.

[0048] Figure 1 A contact lens structure 100 is shown. Figure 1 The example shown in FIG. 1 is a scleral contact lens. The contact lens structure 100 includes an outer shell 110 made of a rigid gas permeable (RGP) material, and a single gas chamber 120. The contact lens 100 has a smart platform having a large central planar component 130 embedded therein.

[0049] In this disclosure, terms such as "outer", "outermost", "above", "top", "upper", and "front" refer to the direction away from the eye of a patient wearing the contact lens, while "inner", "innermost", "lower", "bottom", "lower", and "back" refer to the direction of the patient's eye.

[0050] Figure 1 Definitions of the various surfaces of the contact lens structure 100 are provided. These surfaces may be defined as:

[0051] - a housing front surface 111 and a housing rear surface 112 corresponding to the outermost surface and the innermost surface of the housing 110, respectively;

[0052] - An air chamber front surface 121 and an air chamber rear surface 122 corresponding to the outer surface and the inner surface of the air chamber 120 respectively.

[0053] In addition, Figure 1 Three zones or areas of the contact lens 100 have been distinguished, as are commonly distinguished for scleral lenses: an optical zone 110a, which substantially coincides with a central portion of the contact lens and where light is collected, altered or generated and sent to the retina of the eye; a landing zone 100c, which substantially coincides with an outer portion or periphery of the contact lens and where the contact lens contacts the sclera of the eye; and a transition zone 100b, which connects the optical zone 100a to the landing zone 100c.

[0054] The contact lens structure 100 further defines a permeable zone 100d. The permeable zone 100d includes a region of the front layer 113 that is free of electronic components (eg, planar components), thereby facilitating the flow of oxygen within the contact lens to the air chamber 120.

[0055] The front surface 111 has a plane portion 111f having a radius of curvature greater than the radius of curvature of other portions of the front surface 111. The plane portion 111f extends over the entire or at least substantially the entire optical zone 100a. The plane portion 111f extends over the entire or at least substantially the entire plane component 130. The plane portion 111f is shaped to provide the desired back vertex power of the contact lens structure 100. The absolute value of the radius of curvature of the plane portion 111f is greater than 20 mm. Since the radius of curvature of the plane portion 111f is larger than that of a conventional contact lens structure having a radius of curvature substantially equal to the radius of curvature of the entire shell, the contact lens structure 100 of the present invention enables a compact design of the contact lens structure 100, wherein the embedded plane component 130 and the desired back vertex power are substantially determined by the radius of curvature of the plane portion 111f of the front surface 111. The back vertex power can also be provided by the shape of the plane portion 111f in combination with the air chamber 120 and / or the back surface 112.

[0056] The air chamber 120 is included in the shell 110 and is substantially located in the center of the contact lens structure 100, thereby covering the optical zone 110a and at least a portion of the transition zone 100b. In some embodiments, the air chamber 120 further extends into a portion of the landing zone 100c. The air chamber 120 is included in the front layer 113 and the back layer 114 of the shell 110. Therefore, the front layer 113 is included in the shell front surface 111 and the air chamber front surface 121; the back layer 114 is included in the shell back surface 112 and the air chamber back surface 122.

[0057] In this embodiment, the smart platform includes only a planar component 130, which is centrally located in the contact lens 100 and, as just explained, adjacent to and / or attached to the rear surface of the front layer 113 of the housing. The smart platform can be smaller, equal to, or larger than the optical zone 100a of the contact lens structure 100. Typical dimensions of the smart platform (planar component 130) are between 1 mm and 10 mm in diameter. The planar component 130 also has a front or outer surface 131 and a rear or inner surface 132.

[0058] Planar component 130 can be a device that modulates light entering the optical zone of the contact lens structure, such as a switchable spectral filter, an artificial iris, or a switchable Fresnel lens. Planar component 130 of the smart platform can also be a display that generates light (such as a microLED display), or a combination of the two, such as a transparent OLED display with an active modulator. Planar component 130 can be the only component embedded in contact lens 100, such as Figure 1 As in the example.

[0059] The smart platform may also include not only the central plane component 130, but also other components, such as other electronic devices that are not necessarily completely flat. Figure 2 This is shown schematically in . Figure 3 An example embodiment of a smart platform or platform assembly is illustrated in FIG. The platform assembly includes a planar assembly 130 and an annular assembly 133. The annular assembly extends radially outward from the planar assembly 130. There may be at least one opening 134 between the planar assembly 130 and the annular portion 133. The at least one opening 134 may provide a permeable zone 100d through which oxygen may move through the front layer 113 to reach the air chamber 120. The air chamber 120 and the platform including the planar assembly 130 and the annular portion 133 may have a common radial extension. There may be a plurality of connecting members 135 connecting the planar assembly 130 to the annular assembly 133 between the planar assembly 130 and the annular assembly 133, and the opening 134 is formed between the plurality of connecting members.

[0060] The air chamber 120 has several functions, which determine the size of the air chamber. First, the air chamber is used as a highly oxygen permeable reservoir, which compensates for the oxygen impermeability of the planar component 130. The air chamber 120 also allows the lens geometry required for the embedding of the planar component 130. It is known that the diffusion of oxygen in air is more than 1000 times that in the most oxygen permeable RGP material. Therefore, the air chamber 130 can be considered as an oxygen isobaric volume, and the obstacle it poses to oxygen permeability is negligible. As a result, the air chamber 120 allows the geometry of the contact lens structure 100 to be changed so as to embed a large planar component without compromising oxygen permeability. In addition, since the size of the air chamber 120 is determined to cover the entire corneal tissue in this case, the air chamber can also oxygenate the central corneal tissue of the contact lens wearer despite the presence of the oxygen impermeable planar component 130 covering the eye tissue. This is due to the fact that the contact lens structure 100 includes a permeability zone 100d, through which oxygen is transported from the front layer 113 of the shell toward the back layer 114 of the shell. In the absence of the air chamber 120, such oxygen delivery is not possible because the oxygen permeability of the RGP material is too low to allow effective oxygen delivery within the contact lens. Therefore, when a large oxygen-impermeable component such as a smart platform covers the corneal tissue, the absence of the air chamber 120 will result in severe corneal edema. The planar component 130 (and optionally other electronic devices) may include one or more openings 134 or perforations to enable oxygen delivery through the otherwise oxygen-impermeable planar component 130.

[0061] Due to the above reasons and in order to obtain satisfactory optical properties, the air cell should cover the entire optical zone, which means that there is a distance between the planar component and the RGP back layer at the center of the lens. The typical distance is between 20μm and 200μm, which is beneficial to the optical performance of the lens. Figure 6 A portion of a contact lens structure 100 is illustrated, wherein a separation distance D is indicated between the front surface 122 of the rear layer 114 and the rear surface 132 of the planar component 130. This separation distance D at the center of the rear surface 112 of the housing is preferably between 20 μm and 200 μm.

[0062] Another advantage of the contact lens structure 100 is that because the air chamber 120 does not increase the mass of the resulting contact lens structure, the thickness of the contact lens structure can be increased so that the planar component 130 can be embedded without increasing the overall mass of the lens, which makes the lens comfortable for the patient. Conventional scleral designs without air chambers would be too heavy and uncomfortable when embedded in a large planar component.

[0063] The air chamber 120 further serves as an optical material that helps reduce the center thickness and overall mass of the scleral lens. In conventional scleral lenses, the back vertex power P of the contact lens is determined by the sum of the respective optical powers F1 and F2 of the front and back surfaces, and has a correction factor due to the thickness t of the lens:

[0064]

[0065]

[0066]

[0067] n is the refractive index of the RGP material, r1 and r2 are the radii of curvature of the front and back surfaces, respectively (see Figure 4 ). The above formula makes r1 close to r2. As an example, for a conventional contact lens with a refractive index close to 1.45, a thickness equal to 500 μm, a back vertex power of 10D, and a back curvature r2 equal to 7.8 mm, r1 will be close to 6.75 mm (see Figure 4 , which represents a conventional +10D scleral lens 200, r1 and r2 are defined as the radii of curvature of the front center surface and the back center surface, respectively).

[0068] In the contact lens structure 100 of the present invention, the air chamber 120 is introduced as a part of the contact lens structure 100. The optical zone 100a of the contact lens structure is a stack composed of the RGP front layer 113, the planar component 130, the air chamber 120 and the RGP rear layer 114. The back vertex power of the stack can be changed similar to a conventional scleral lens by modifying the back vertex power of the RGP rear layer 114 determined by the curvature radius of the RGP rear surface 112 and the air chamber rear surface 122, and can also be changed by changing the curvature radius of the RGP front layer 113. This allows a lot of flexibility in defining the center thickness of the scleral lens. As an example, the RGP rear layer 114 can be considered to be afocal (no light focal length), that is, the curvature radius of the air chamber rear surface 122 is equal to the sum of the curvature radius of the RGP rear surface 112 and the center thickness of the RGP rear layer 114 scaled in proportion. In this case, the back vertex power of the lens is determined only by the curvature radius of the RGP front layer 113 and the optical path length of the entire stack. To achieve back vertex powers between -20D and 20D, the radius of curvature of the RGP front surface should be less than -20mm (negative power) and greater than 20mm (positive power). This in turn allows the center thickness of the RGP front layer 113 to be less than 400μm for the power. Patient comfort is better due to the reduced mass and reduced center thickness of the RGP front layer compared to a conventional scleral lens embedded with the same assembly.

[0069] Figure 5A conventional scleral lens 200 (top image) and a scleral contact lens structure 100 (bottom image) embedded in the same 7.5 mm planar component 130 are shown. The contact lens material (RGP in this case) used in both lenses is the same. The proposed design has an air chamber 120, which is located behind the planar component 130. Both lenses have the same RGP rear surface, the same landing zone and provide a +10D rear vertex power. It should be understood that the center thickness of the contact lens structure 100 is much smaller than the center thickness of a conventional scleral lens. In addition, the introduction of the air chamber reduces the mass of the contact lens structure, both because there is no material in the transition zone 100b and because the need for a thick RGP front layer in the optical zone 100a is avoided. The reduced center thickness and reduced overall mass both increase the lens comfort for the patient.

[0070] The function of the housing 110, typically made of RGP material, is first to embed the planar component 130 and optionally the larger platform component 133. The housing 110 also provides mechanical strength for the scleral contact lens. Additional functions are defined by the functions of the front and rear layers of the RGP.

[0071] The RGP front layer 113 basically has two functions:

[0072] 1. It is due to the back vertex power of the lens, as described above.

[0073] 2. It allows oxygen to penetrate from the environment to the air chamber 120. This penetration mainly occurs in the area 100d (i.e., the permeable area 100d) outside the planar component 130 and at the interface between the RGP front layer 113 and the air chamber 120. The thickness of the RGP front layer 113 in the permeable area 100d is derived from the trade-off between the efficient oxygen permeability and mechanical strength of the complete scleral lens, and is in the range of 50 μm to 500 μm.

[0074] The RGP back layer 114 has the following basic functions.

[0075] The RGP posterior surface 112 is customized for the patient to allow for a good fit with the eye. In general, the radius of curvature of the optical zone 100a, the overall sagittal depth of the lens, the overall diameter of the lens, and the landing zone 100c definition are selected by a trained fitter to allow the lens to be properly fitted to the eye. In addition, the landing zone 100c can be complex, i.e., have different radii of curvature along two orthogonal meridians, or be quadrant specific to allow for a better fit. In general, the center radius of curvature of the posterior surface is typically between 6.0 mm and 10.0 mm. The overall diameter of the lens depends largely on the embedded planar component 130 and can be between 14.5 mm and 25 mm. Variations in the sagittal depth and landing zone definitions depend largely on the lens diameter selected.

[0076] Furthermore, the RGP rear layer 114 allows oxygen to penetrate from the air chamber 120 to the fornix between the cornea and the lens. This penetration occurs along the optical zone 100a and the portion of the transition zone 100b covering the corneal tissue. The thickness of the rear layer 114 in these zones 100a, 100b is derived from a trade-off between efficient oxygen permeability and mechanical strength of a complete scleral lens and is in the range of 50 μm to 500 μm.

[0077] Finally, the RGP rear layer 114 can but need not contribute to the back vertex power of the lens. When the radius of curvature of the air chamber rear surface 122 is selected so that the RGP rear layer 114 is non-focal, the rear layer contributes to the back vertex power of the lens. This can help reduce the absolute radius of curvature of the RGP front surface 111 to achieve a more comfortable fit for the patient. For example, in the case of a desired -20D lens, the afocal RGP rear layer 114 results in a radius of curvature of approximately -20mm. The concave RGP front surface 111 may cause discomfort to the patient. However, when the radius of curvature of the RGP rear surface 112 and the air chamber rear surface 122 are selected so that the RGP rear layer achieves -20D optical power, a flat RGP front surface 111 can be selected, which may be more comfortable for the patient.

[0078] Figure 7 The diagram shows Figure 1 An alternative embodiment of the compact lens structure 100 compared to the embodiment in , in which the air chamber 120 only partially extends into the transition zone 100b, and does not extend into the landing zone 100c. The permeable zone 100d is thus narrower, but can still provide a desired level of air permeability into the air chamber 120.

[0079] The present disclosure is obviously not limited to the specific embodiments described herein, but also covers any changes (e.g., regarding the selection of materials, dimensions, components, configurations, etc.) that a person skilled in the art may consider within the general scope of the present disclosure defined by the claims.

[0080] In this document, the terms "comprise", "include" and their derivatives (such as "comprising", "including", etc.) should not be understood as exclusive, that is, these terms should not be interpreted as excluding the possibility that the described and defined content may include additional elements, steps, etc.

Claims

1. A contact lens structure (100), comprising: - a housing (110) having a front layer (113) and a rear layer (114), wherein the rear vertex power of the contact lens structure is generated at least by the optical power of the front layer (113) and the rear layer (114); and - an air chamber (120) located entirely within the shell (110) and between the front layer (113) and the rear layer (114) of the shell (110); The contact lens structure further comprises a planar component, which is at least partially arranged in the air chamber (120) and in the optical zone (100a) of the contact lens structure (100).

2. The contact lens structure (100) according to claim 1, wherein: The front layer (113) comprises a front surface (111) comprising at least a substantially planar portion (101).

3. The contact lens structure (100) according to claim 2, wherein: The planar portion (101) extends substantially over the entire planar component.

4. The contact lens structure (100) according to claim 2 or 3, wherein: The curvature radius of the planar portion (101) is greater than the curvature radius of other portions of the front surface (111).

5. The contact lens structure (100) according to any one of claims 2 to 4, wherein: The absolute value of the curvature radius of the plane portion (111f) is greater than 20 mm.

6. The contact lens structure (100) according to any one of claims 2 to 5, wherein: The contact lens structure includes a transition zone and / or a landing zone, wherein the transition zone and / or the landing zone are zones radially outside the optical zone (100a), and wherein the radius of curvature of the planar portion (111f) of the front surface is greater than the radius of curvature of the portion of the front surface at the transition zone and / or the landing zone.

7. The contact lens structure (100) according to any one of claims 2 to 6, wherein: The back vertex power of the contact lens structure depends on the curvature of the planar portion (101).

8. A contact lens structure (100) as claimed in any preceding claim, wherein: The planar component (130) extends substantially across the entire optical zone (100a).

9. A contact lens structure (100) as claimed in any preceding claim, wherein: The thickness of the front layer is between 100 μm and 400 μm.

10. The contact lens structure (100) according to claims 3 and 4, wherein: The planar component (130) is disposed adjacent to the planar portion (111f).

11. The contact lens structure (100) of any one of the preceding claims, further comprising a permeable zone (100d), wherein: The permeable zone is the portion of the front layer (113) outside the optical zone (100a).

12. A contact lens structure (100) as claimed in any preceding claim, wherein: The air chamber (120) is dimensioned to cover a solid angle between 0.5*π and 0.9*π when viewed from the center of curvature of the rear surface.

13. A contact lens structure (100) as claimed in any one of the preceding claims, wherein: The planar component is arranged at a distance of between 20 μm and 200 μm from the rear layer at the center of curvature of the rear surface.

14. The contact lens structure (100) according to claim 13, wherein: The distance is the distance through the air chamber (120).

15. The contact lens structure (100) as claimed in any preceding claim, further comprising a component platform, the component platform comprising the planar component (130) and an annular component (133) arranged radially outward of the planar component, and wherein, At least one opening (134) is formed between the planar component (130) and the annular component (133), and oxygen is configured to pass through the front layer (113) and reach the gas chamber (120) through the at least one opening (134).

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