Contact lenses

Abstract

During use, the contact lens (10) forms a hollow space between its concave inner surface and the convex outer surface of the eye, and due to the presence of multiple microprotrusions (13), the contact lens (10) contacts the corneal epithelium only on a portion of its inner surface facing the eye, and the microprotrusions (13) allow the contact lens (10) to be raised a few micrometers relative to the corneal surface.

Description

Technical Field

[0001] The embodiments described herein relate to contact lenses designed to compensate for the most common vision defects, such as myopia, hyperopia, astigmatism, and presbyopia. Background Technology

[0002] As we all know, there are many types of contact lenses available today, which can be broadly categorized into the following two main types:

[0003] - Soft contact lenses;

[0004] - Rigid gas permeable (RGP) contact lenses.

[0005] Soft contact lenses are the most common type. They adapt more easily to the cornea, remain stable in the position of use under any conditions, and are characterized by the presence of an aqueous component in their structure, which varies by volume between 36% and 65%.

[0006] The presence of hydrophilic materials allows soft contact lenses to absorb the tear film, creating a "sponge effect" that promotes oxygen flow from the front surface of the lens to the back surface, thereby nourishing the cornea.

[0007] On the other hand, if soft contact lenses are not adequately and continuously moistened by the tear film, they will dry out, leading to corneal dehydration and malnutrition.

[0008] Another drawback is that as soft contact lenses dry out, the material becomes less flexible, resulting in a smaller base radius value for the lens itself (which is narrower), making them less comfortable to wear.

[0009] The hydrophilic properties of soft contact lenses also lead to the retention of bacteria, viruses, and various dirt inside the lens itself, which can cause various serious eye infections.

[0010] In short, soft contact lenses can correct almost all visual refractive errors, but are particularly suitable for good or excellent tearing and require careful cleaning.

[0011] Another type of contact lens is represented by rigid gas permeable (RGP) lenses, which are less flexible than soft lenses and therefore maintain their shape once worn.

[0012] Even with irregular corneas, this unique feature can achieve good visual quality.

[0013] RGP contact lenses are made of hydrophobic materials that prevent the "sponge effect" typical of soft contact lenses and allow the tear film, which remains between the posterior surface and the anterior surface of the cornea, to better oxygenate the cornea itself.

[0014] In addition, once RGP contact lenses are worn, they do not come into complete contact with the corneal epithelium, but rather float on the surface formed by the tear film layer, thus providing greater respect for the physiological environment of the eye.

[0015] In addition, RGP contact lenses with reduced wettability are better from a hygiene perspective because they do not absorb or allow foreign substances deposited on their surface to pass through, thus reducing the risk of infection.

[0016] However, the main drawback of RGP contact lenses is that they are made of rigid materials, which leads to lower tolerance and comfort compared to soft contact lenses, especially during first-time use.

[0017] In short, RGP contact lenses can correct almost all visual refractive errors. RGP contact lenses are suitable for cases of corneal irregularities and even moderate tearing, but RGP contact lenses are not very comfortable.

[0018] Several solutions have been proposed. For example, document US5044742 describes a contact lens with disc-shaped protrusions on its inner surface. In order to accommodate the tear film, these protrusions form cavities to increase the amount of tear film between the lens and the eye.

[0019] Document GB1173515 describes a contact lens with millimeter-sized annular protrusions on its eye-facing surface to retain a large amount of tear film. However, these annular protrusions alter the normal distribution of the tear film.

[0020] US2015 / 153588 describes a lens with nanoprotrusions on its inner surface, intended to increase the lubricity of the silicone hydrogel lens.

[0021] US7878650 discloses a lens with hemispherical protrusions on its inner surface for underwater use, capable of resisting the capture of microorganisms on the eye surface covered by the lens, thereby reducing the probability of microbial infection of the eye. Therefore, the lens in this document can be worn for extended periods, especially in aquatic environments.

[0022] The above technical solutions cannot fully meet the needs of the industry.

[0023] Therefore, there is a need to improve a contact lens that can overcome at least one of the shortcomings of existing technologies.

[0024] In particular, one object of the present invention is to provide a contact lens similar to currently known soft contact lenses, adapted to the structure of the cornea, and improving use tolerance and comfort under any circumstances.

[0025] Another object of the present invention is to provide a non-hydrophilic contact lens that, once worn, allows the tear film to remain within the gap created between the cornea and the lens itself without being absorbed (without the “sponge effect”), thus maintaining tearing in its natural state in a manner similar to but better than that of known RGP contact lenses.

[0026] Another objective is to provide a contact lens that, once worn, allows the tear film to move freely between the cornea and the lens, at least during eye movements or eyelid blinking.

[0027] Another object of the present invention is to provide a contact lens that does not allow any possible foreign matter to pass through its surface, thereby greatly reducing the risk of infection and simplifying daily maintenance.

[0028] Finally, an object of the present invention is to provide a contact lens whose production cost is not lower than that of known contact lenses, but is comparable to that of known contact lenses.

[0029] In short, one object of the present invention is to provide a contact lens that allows for the combination of all the advantages of currently available contact lenses (i.e., the aforementioned soft contact lenses and rigid gas permeable (RGP) contact lenses), characterized by the absence of relative disadvantages and a significant reduction in problems caused by current lenses.

[0030] The applicant has designed, tested and implemented the present invention to overcome the disadvantages of the prior art and to obtain these and other objectives and advantages. Summary of the Invention

[0031] The invention is set forth and characterized in the independent claims. The dependent claims describe other features of the invention or variations of the main inventive concept.

[0032] For the aforementioned purpose, a contact lens made of a non-hydrophilic material is provided, the contact lens being concave in shape and comprising an inner, outer, completely smooth surface, within which an inner region and a recessed outer peripheral region are defined, the outer peripheral region being completely outside the inner region. During use, both regions face the eye.

[0033] Contact lenses consist of multiple micro-protrusions that face the eye during use, allowing the lens to be raised a few micrometers relative to the corneal surface, for example, by an amount between 7 and 10 micrometers.

[0034] According to some embodiments of the lens, the microprotrusions are only located within the peripheral region as described above.

[0035] These microprotrusions form from the base and connect to the lens, especially away from the inner surface of the lens. The microprotrusions extend upwards in height, adapted to maintain contact with the corneal epithelium.

[0036] According to one variation, the contact lens may also include multiple pores in the peripheral region, with microprotrusions scattered throughout.

[0037] Advantageously, contact lenses have a reduced thickness compared to lenses currently included in the prior art.

[0038] Due to the presence of microprotrusions and / or the possible presence of pores, and due to the reduced thickness and being made of a non-hydrophilic material, the limitations of the prior art can be overcome and the defects present in the prior art can be eliminated.

[0039] In particular, a contact lens has been developed that does not alter the natural and physiological hydration and nutrition of the cornea, provides high comfort under any usage conditions, carries a very low risk of eye infection, and is simple to maintain daily.

[0040] Furthermore, the manufacturing cost is comparable to that of existing contact lenses.

[0041] Furthermore, the contact lenses in question are characterized by a medium to low surface contact angle, between 10° and 60°. Advantageously, this surface contact angle allows for a lens in which fluid can easily flow through the space defined between the microprotrusions, while also minimizing friction between the lens and the eyelid, thus providing the user with a very comfortable lens to wear. Attached Figure Description

[0042] These and other aspects, features, and advantages of the invention will become apparent from the following description of some embodiments, which are given by way of non-limiting example with reference to the accompanying drawings, wherein:

[0043] - Figure 1 This is a top view of the recess of a contact lens according to an embodiment described herein;

[0044] - Figure 1a It shows Figure 1 Magnified details of a portion of the outer peripheral area of ​​the contact lens;

[0045] - Figure 2a , 2b 2c is based on possible embodiments, Figure 1a A magnified perspective view of detail A shown;

[0046] - Figure 3a , 3b 3c and 3d show details of the contact lens according to possible embodiments;

[0047] - Figure 4 The illustrations show the different possible constructions. Figure 3c Details;

[0048] - Figure 5 Details of contact lenses according to different embodiments are illustrated schematically.

[0049] For ease of understanding, the same reference numerals are used to identify the same common elements in the figures where possible. It will be understood that elements and features of one embodiment can be readily incorporated into other embodiments without further explanation. Detailed Implementation

[0050] We will now refer in detail to possible embodiments of the invention, one or more of which are illustrated in the accompanying drawings. Each embodiment is provided by way of illustration and should not be construed as limiting the invention. For example, one or more features shown or described, as they are part of one embodiment, may be changed or adopted in other embodiments, or combined with other embodiments to produce further embodiments. It should be understood that the invention should include all such possible modifications and variations.

[0051] Before describing these embodiments, we must also clarify that this specification is not limited to its application to the details of the construction and arrangement of the components as described in the following description using the accompanying drawings. This specification may provide other embodiments and may be obtained or implemented in various other ways. We must also clarify that the wording and terminology used herein are for descriptive purposes only and should not be considered limiting.

[0052] The accompanying drawings illustrate some embodiments of contact lenses, which are designated by reference numeral 10.

[0053] refer to Figure 1 The contact lens 10 according to the invention includes an inner region 11 extending within a visible diameter Dv, the visible diameter Dv being smaller than the outer diameter De of the contact lens 10. This inner region 11 is smooth and faces the eye during use.

[0054] Advantageously, in all embodiments described below and shown in the accompanying drawings, the contact lens 10 is made of a combination of non-hydrophilic, biocompatible polymeric materials known in the art, such as poly(methyl acrylate) (PMA).

[0055] The contact lens 10 is concave in shape, so the internal region 11 also has the same concave shape.

[0056] Here and throughout this specification, the term “smooth” is intended to refer to the surface finish of the inner region 11, which has a high degree of smoothness on one side, having a surface finish suitable for contact with the eye, and on the other side is completely free of any protrusions from the surface of the inner region toward the eye.

[0057] The visible diameter Dv is preferably determined by the maximum size of the contour projection related to the maximum expansion of the pupil on the concave surface of the contact lens 10 facing the eye.

[0058] Referring to the human eye and according to a preferred embodiment, the inner region 11 is defined by a circle of diameter Dv that is concentric with the circumference of diameter De.

[0059] The visible diameter Dv has a maximum value that is indicatively equal to 8 mm, and its typical preferred value is between 4.5 mm and 5 mm, while the outer diameter De of the contact lens 10 is indicatively between 9 mm and 13 mm.

[0060] Furthermore, the contact lens 10 includes an outer peripheral region 12 that is completely outside the inner region 11 and therefore completely outside the visible diameter Dv, and the outer peripheral region 12 extends at most to the outer diameter De. This annular outer peripheral region 12 extends between the visible diameter Dv and the outer diameter De, configured as a natural continuation of the inner region 11; for this purpose, the outer peripheral region 12 is also generally concave.

[0061] According to one variant, in Figure 2a As can be seen in the magnified image, the contact lens 10 consists of only a plurality of micro-protrusions 13, which are configured to face the eye during use.

[0062] According to some embodiments described herein, these microprotrusions 13, which may also be referred to as “pillars” or “micropillars”, are formed in the peripheral region 12.

[0063] According to a preferred embodiment, the microprotrusions 13 are disposed on the entire inner surface of the outer peripheral region 12 and are configured to extend from the visible diameter Dv to the outer diameter De.

[0064] Preferably, the microprotrusions 13 are uniformly distributed on the entire inner surface of the peripheral region 12, for example, according to a geometric pattern defined by multiple rows radially away from the center of the contact lens 10.

[0065] The microprotrusion 13 advantageously includes a base 14 and a top 15, the base 14 being connected to the peripheral region 12 of the contact lens 10, and the top 15 being configured and adapted to rest on and maintain contact with the cornea of ​​the eye. Advantageously, the microprotrusion 13 is integrated with the contact lens 10 as a single piece and made of the same material as the contact lens 10.

[0066] According to some preferred embodiments, in a non-limiting manner and with particular reference, Figure 3a , 3b 3c and 3d, microprotrusion 13 has a crown-like structure ( Figure 3a ), or has a structure based on a hemispherical shape ( Figure 3b ), or it may also have a structure based on a cylindrical shape ( Figure 3c ), or has a construction based on the shape of a truncated cone ( Figure 3d ).

[0067] In other possible non-preferred embodiments, the microprotrusions 13 have elliptical, parabolic, or prismatic shapes; for example, they are typically shaped as parallelepipeds, truncated pyramids, or polyhedra.

[0068] It should be noted that in the example shown in the attached figure, the microprotrusions have a symmetrical structure, but asymmetrical structures can also be provided for the microprotrusions. This applies to any shape that can be given to the microprotrusions.

[0069] In any case, preferably, the microprotrusions 13 have a flat or convex outer surface, i.e., they do not have cavities. In particular, at least the surface of the top 15, which serves as the surface in contact with the eye, is flat or convex.

[0070] As shown in the figure, the microprotrusions 13 therefore have a micropillar structure. They do not have, for example, annular shapes that have a central cavity that retains a portion of the tear film.

[0071] According to some embodiments, purely as a non-limiting example, some reference manufacturing values ​​are given below regarding the geometry of the microprotrusions 13 disposed on the contact lens 10.

[0072] Given that the maximum thickness of the tear film is indicatively between 8.5 μm and 9.5 μm, the heights H1, H2, H3 and H4 of each microprotrusion 13 are indicatively between 5 μm and 25 μm in a non-limiting manner, preferably and advantageously equal to about 10 μm.

[0073] Furthermore, the base diameters D1, D2, D3, and D4 of each microprotrusion 13 are between 5 μm and 255 μm in a non-restrictive manner.

[0074] Specifically, refer to the hemispherical shape ( Figure 3b ) and cylindrical shape ( Figure 3c The base diameters D2 and D3 are in a non-limiting manner between 5 μm and 250 μm, preferably equal to about 50 μm. Finally, referencing the truncated cone shape ( Figure 3d The base diameter D4 is between 7 μm and 255 μm in a non-limiting manner, preferably equal to about 54 μm.

[0075] In addition, especially reference Figure 3c and Figure 3d , Figure 3c and Figure 3d These involve microprotrusions having cylindrical and truncated conical shapes, respectively, with the top 15 defining a circular or convex surface that contacts the eye. In other words, a curved surface corresponding to the top 15 of the microprotrusion 13 is defined, with its radii of curvature Rb3, Rb4 being in a non-limiting manner between 30 μm and 13,000 μm, preferably equal to about 500 μm.

[0076] The top 15 is further characterized by the presence of inclined surfaces sm3 and sm4 connecting the top 15 to the base 14. By way of a non-limiting example, the inclined surfaces sm3 and sm4 have an angle of inclination relative to the plane of the base 14 parallel to the micro-protrusion 13, which is between 10° and 50°, preferably equal to about 25°.

[0077] According to some embodiments, each microprotrusion 13 has its own longitudinal axis, which, depending on its orientation, defines the tilt angle of the microprotrusion 13 itself relative to the surface of the peripheral region 12 of the contact lens 10 extending from the microprotrusion 13 (see [reference]). Figure 4 (A cylindrical microprotrusion is shown as a non-limiting example). Specifically, the tilt angle α is non-limitingly between α1 = 80° and α2 = 100°, preferably α = 90°, under which condition the axis of the microprotrusion 13 is perpendicular to the surface of the outer peripheral region 12 of the contact lens 10. See also... Figure 4 The three structures in the image show angles α = 90°, α1 = 80°, and α2 = 100° from left to right.

[0078] According to some embodiments, as a whole, the microprotrusions 13 having the above-described geometric features preferably occupy between 6% and 50% of the extended area corresponding to the peripheral region 12 of the contact lens 10, which extends in an annular crown between the visible diameter Dv and the outer diameter De. More preferably, the microprotrusions 13 occupy at least 20% of the extended area corresponding to the peripheral region 12 of the lens, particularly occupying a portion between 35% and 50% of that area.

[0079] Furthermore, the micro-protrusions 13 are preferably arranged in a uniform and orderly manner in the outer peripheral region 12 according to a circular and / or elliptical orientation.

[0080] refer to Figure 5 According to an exemplary embodiment, two microprotrusions 13, one adjacent to the other and having a cylindrical and / or truncated cone shape, have a spacing p2 between 30 μm and 500 μm, preferably equal to 100 μm.

[0081] Based on the above description of "steps", refer to Figure 5 In the embodiments, we refer to the radial distance between the centers of the microprotrusions 13.

[0082] Refer again Figure 5 The configurations of microprotrusions 13 with a spherical cap shape and a spacing p1, and those with a hemispherical shape and a spacing p2, represent possible non-preferred embodiments. It is assumed that the contact surface between the microprotrusions 13 and the cornea is merely punctual, thus the stability of the contact lens 10 during movement is not optimal. Furthermore, if the microprotrusions 13 have a spherical cap shape, the hollow space created between the contact lens 10 and the cornea in the area outside the visible diameter Dv is quite limited, impairing optimal tear film circulation.

[0083] Advantageously, the material used to manufacture the lens is selected from materials known in the prior art and is biocompatible, non-hydrophilic, and more preferably has a medium / low surface contact angle, i.e., a medium / high wettability value, so as to generate stable adhesion between the corneal epithelium, tear film, lens surface, and walls of microprotrusions. In this way, the tear film can be uniformly and stably distributed in the hollow space between the cornea and the lens.

[0084] Finally, in a non-limiting manner, a preferred embodiment that ensures complete comfort for the contact lens wearer consists of a cylindrical shape ( Figure 3c ) and truncated cone shape ( Figure 3d The contact lens 10 is represented by the microprotrusion 13. In fact, through these two approaches, ideal conditions for tear exchange and excellent stability of the contact lens are advantageously obtained, which is due to the contact surface formed at the top 15 of the microprotrusion 13.

[0085] Using the shape, size, and arrangement of the cylindrical and truncated cone-shaped microprotrusions 13 described above, the total number of microprotrusions 13 that each contact lens 10 may contain is between 300 and 65,000 in a non-limiting manner, preferably between 5,000 and 20,000, and more preferably between 8,000 and 15,000.

[0086] According to the reference Figure 1a and 2b In the described alternative embodiment, the contact lens 10 includes a plurality of microprotrusions 13 and a plurality of holes 16 or micropores in the peripheral region 12, outside the visible diameter Dv, the holes being formed on the lens surface, the holes being positioned such that they can be inserted into the nearby different microprotrusions 13 (e.g. Figure 2b Between the four micro-protrusions in the middle. Figure 1 and Figure 1a The magnified view of the contact lens 10 shows the presence of both microprotrusions 13 and apertures 16. However, it is clear that... Figure 1a It also shows according to Figure 2a The enlarged view shows a variant of contact lens 10 without holes 16, because the size and number of holes 16 do not change the overall appearance of the lens, even though the lens does not have holes 16.

[0087] According to another embodiment, which is not included within the scope of protection of this patent application, such as... Figure 2c As shown in the enlarged schematic diagram, a contact lens 10 can be provided that has no microprotrusions 13 and only has a plurality of micropores 16 inside.

[0088] According to other preferred embodiments, the hole 16 is disposed within the outer peripheral region 12, starting from the visible diameter Dv and extending to the outer diameter De.

[0089] According to other preferred embodiments, the holes 16 are distributed uniformly and neatly in a non-limiting manner, for example, in a radial pattern starting from the center of the lens, or in a circular and / or elliptical orientation.

[0090] Hole 16 is a through hole that connects the inner surface of lens 10 with the outer surface of lens 10, and is designed to contact the eyelid and tear film.

[0091] Advantageously, the presence of these pores 16 increases the circulation and exchange of tears and increases the oxygenation of the cornea.

[0092] According to some embodiments, the diameter of the hole 16 is between 3 μm and 20 μm in a non-limiting manner, preferably equal to about 10 μm.

[0093] Therefore, each contact lens 10 having microprotrusions 13 may include holes, the total number of which is in a non-limiting manner between 100 and 1000, preferably between 400 and 600.

[0094] Advantageously, the contact lens 10 having microprotrusions 13 and / or pores 16 is made of a non-hydrophilic biocompatible material and simultaneously possesses excellent properties of adaptability to the corneal surface and a medium / low surface contact angle. In particular, the thickness of the obtained contact lens 10 is indicatively between 60 μm and 150 μm, which is thinner than soft contact lenses (thickness between 100 μm and 200 μm) and RGP contact lenses (thickness between 170 μm and 250 μm).

[0095] Therefore, the properties of the materials used to produce the contact lenses 10 with microprotrusions 13 and / or holes 16 according to the present invention allow for the acquisition of contact lenses 10 with excellent durability, wearing comfort and hygiene.

[0096] In fact, due to the presence of the microprotrusions 13, approximately 85% of natural tearing is maintained. Simultaneously, the non-hydrophilic material used to manufacture the contact lens 10 with the microprotrusions 13 prevents the lens from becoming hydrophilic, eliminating the so-called "sponge effect" and preventing dirt from penetrating the lens surface. Ultimately, a contact lens 10 with a significantly reduced risk of infection and requiring simple daily maintenance is obtained.

[0097] Therefore, the contact lens 10 with microprotrusions 13 according to the present invention allows for the elimination of problems that often lead patients to abandon contact lenses as an aid to compensate for vision defects (e.g., reduced comfort and risk of infection).

[0098] It is obvious that modifications and / or additions can be made to the above-described contact lenses without departing from the scope and range of the invention as defined by the claims.

[0099] It is also obvious that, although the invention has been described with reference to some specific examples, those skilled in the art will certainly be able to implement many other equivalent forms of contact lenses having the features described in the claims, and all of these are therefore within the scope of protection defined by the claims.

[0100] In the following claims, the references in parentheses serve only for readability: they shall not be regarded as limiting factors on the scope of protection claimed in any particular claim.

Claims

1. A contact lens (10) made of a non-hydrophilic material, characterized in that, The contact lens (10) includes a plurality of microprotrusions (13) which are configured to face the eye during use and to contact the corneal epithelium, thereby raising the contact lens (10) by a few micrometers relative to the corneal surface. The microprotrusions (13) are characterized in that the height (H1, H2, H3, H4) extending from the base (14) to the top (15) of the microprotrusions (13) is between 5 μm and 25 μm. The total number of microprotrusions (13) included in each contact lens (10) is between 300 and 65,000.

2. The contact lens (10) according to claim 1, characterized in that, The contact lens (10) includes an inner region (11) that is smooth and faces the eye during use, the inner region (11) extending within a visible diameter (Dv) smaller than the outer diameter (De) of the contact lens (10), and an outer peripheral region (12) disposed outside the inner region (11) in a ring shape, the outer peripheral region (12) extending between the visible diameter (Dv) and the outer diameter (De).

3. The contact lens (10) according to claim 2, characterized in that, The microprotrusions (13) correspond only to the peripheral region (12).

4. The contact lens (10) according to any one of the preceding claims, characterized in that, The microprotrusion (13) has a base (14) and a top (15), the microprotrusion (13) is integrated with the lens, and the microprotrusion (13) has a cylindrical, truncated cone, elliptical, parabolic or prism shape.

5. The contact lens (10) according to claim 4, characterized in that, The microprotrusion (13) has a cylindrical or truncated cone shape, and the top (15) defines a convex contact surface with the eye, which is conformed to a surface with a radius of curvature (Rb3, Rb4) between 30 μm and 13000 μm.

6. The contact lens (10) according to claim 4, characterized in that, The cylindrical microprotrusions (13) have a base diameter (D3) between 5 μm and 250 μm.

7. The contact lens (10) according to claim 4, characterized in that, The truncated cone-shaped microprotrusions (13) have a base diameter (D4) between 7 μm and 255 μm.

8. The contact lens (10) according to claim 4, characterized in that, Two microprotrusions (13) adjacent to each other and having a cylindrical or truncated cone shape have a spacing (p2), which is understood to be the radial distance between the centers of the microprotrusions, between 30 μm and 500 μm.

9. The contact lens (10) according to claim 2, characterized in that, The microprotrusions (13) are uniformly distributed on the entire inner surface of the peripheral region (12) according to a geometric pattern defined by multiple rows radially away from the center of the lens. The total area of ​​the microprotrusions (13) occupies between 35% and 50% of the area corresponding to the extension of the peripheral region (12).

10. The contact lens (10) according to claim 2, characterized in that, The contact lens (10) includes a plurality of holes (16) in the peripheral region (12), the diameter of which is between 3 μm and 20 μm, and the holes are formed on the surface of the lens, and are positioned such that they are inserted between different microprotrusions (13) arranged in adjacent locations.

11. The contact lens (10) according to claim 1, characterized in that, The contact lens (10) has a medium / low surface contact angle between 10° and 60°.

12. The contact lens (10) according to claim 4, characterized in that, The microprotrusion (13) has a cylindrical or truncated cone shape, and the top (15) defines a convex contact surface with the eye, which is conformed to a surface with a radius of curvature (Rb3, Rb4) of 500 μm.

13. The contact lens (10) according to claim 2, characterized in that, The contact lens (10) includes a plurality of holes (16) in the peripheral region (12), the diameter of the holes being equal to 10 μm, and the holes are formed on the surface of the lens, the holes being positioned such that they can be inserted between different microprotrusions (13) arranged in adjacent locations.

Images