Method for manufacturing an ophthalmic article having at least one microstructured surface and the resulting ophthalmic article

Abstract

The present invention relates to a method for producing an ophthalmic article having at least one microstructured surface, and the ophthalmic article obtained thereby. The method is for producing an ophthalmic article having a major front surface and a major rear surface, at least one of which is a microstructured surface, and includes the steps of: a) providing an ophthalmic substrate (10) having a substrate surface that is either hydrophobic or hydrophilic; b) patterning the substrate surface to create a surface wetting pattern on the substrate surface, the surface including a two-dimensional array of spaced-apart hydrophilic microdomains and at least one hydrophobic zone separating the hydrophilic microdomains from one another; c) coating the two-dimensional array with a hydrophilic liquid capable of forming a scratch-resistant coating in a dried and / or cured state to form spaced-apart droplets (D) of the hydrophilic liquid that are anchored by their wetting properties to the hydrophilic microdomains; and d) drying and / or curing the hydrophilic liquid droplets (D) to produce therefrom a three-dimensional array of microlenses that form the at least one microstructured surface.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an ophthalmic article having at least one microstructured surface and an ophthalmic article obtained thereby. The present invention applies particularly to ophthalmic lenses comprising a three-dimensional array of microlenses configured to control the progression of myopia when the ophthalmic article is a curved prescription ophthalmic lens, although the ophthalmic article may alternatively be incorporated into a smart eyewear device. [Background technology]

[0002] Ophthalmic articles, such as lenses, generally include a base lens substrate shaped to provide a desired optical power and an abrasion-resistant coating (also known as an abrasion-resistant or hard coating) that covers at least one surface of the base lens substrate to prevent it from being damaged by scratches.

[0003] For some applications, it has been found desirable to provide a plurality of microlenses on a base lens substrate in order to locally vary the power of the optical article. For example, US Patent Application Publication No. 2017 / 0131567 A1 discloses a lens comprising a plurality of microlenses formed on the surface of the lens, which allows the microlenses to provide a local variation in power, thereby slowing down the progression of myopia.

[0004] Microlens arrays are therefore used to add a defocusing effect to the periphery of corrective ophthalmic lenses to control the progression of myopia in children. Indeed, today some ophthalmic lenses are specially designed and manufactured for this purpose. However, this approach limits the scalability of this technology to some materials, and certain manufacturing processes (typically using molds) involve additional costs and investments.

[0005] In fact, existing molding processes for microlenses require the delicate microlens surfaces to be protected with other coating materials, which involves the design and fabrication of expensive, precise molds. In particular, in such known processes, a thermoplastic or thermosetting resin is typically injected into a master mold containing a surface replica of the microlens array with an inverted profile. To protect the microlens array and ensure the long-term ophthalmic effect of the ophthalmic article, the molded microlenses are coated with the aforementioned coating material in a subsequent manufacturing step, so that the focal lenses defined by the microlens array are corrected by the refractive index of the specific coating material. Furthermore, this subsequent step is particularly sensitive to control.

[0006] Apart from the fact that known molding manufacturing processes for prescription ophthalmic lenses are complex and costly, another drawback associated with these processes is that such processes are not readily feasible for all ophthalmic lens materials, thereby limiting their versatility and the range of molded ophthalmic articles that are available.

[0007] International Publication No. 2020 / 078964 A1 brochure a base lens substrate having an anterior surface and a posterior surface; - a scratch-resistant coating covering at least one of the front and rear surfaces, the scratch-resistant coating having a first surface at an interface with a base lens substrate and a second surface opposite the first surface; - at least one optical element protruding from one of the first and second surfaces of the scratch-resistant coating, the optical element being made from a material suitable for forming a scratch-resistant coating and capable of being formed from the same scratch-resistant coating by additive manufacturing, photolithography, hot embossing or injection molding; The present invention relates to an optical article comprising:

[0008] The paper "Characterization of a polymer microlens fabricated by use of the hydrophobic effect," by Daniel M. Hartmann, Osman Kibar, and Sadik C. Esener, July 1, 2000, Vol. 25, No. 13, OPTICS LETTERS 975, describes a method for creating hydrophilic domains on a hydrophobic background by lithographically patterning an adhesive hydrophobic layer. Polymer microlenses were fabricated using a dip-coating technique on a variety of inorganic substrates (e.g., SiO2, SiN, GaAs, InP), with sizes ranging from 2 μm to 500 μm in diameter.

[0009] It should be noted that this paper is directed to optical systems in optical-based applications and does not disclose ophthalmic articles such as ophthalmic lenses or eyewear articles. Summary of the Invention [Problem to be solved by the invention]

[0010] It is an object of the present invention to overcome at least the above-mentioned drawbacks by providing a method for manufacturing an ophthalmic article having an anterior major surface and a posterior major surface, at least one of which is a microstructured surface, by a simple additive process that allows for the adaptation of existing ophthalmic articles of any material and geometry, such as curved prescription lenses, with an array of microlenses having high mechanical resistance, so that the supply of a wide variety of myopia control lenses is simplified, without modifying either the underlying lens blank or the supply chain for finished lenses. [Means for solving the problem]

[0011] According to the present invention, the manufacturing method comprises: a) providing an ophthalmic substrate having a substrate surface that is either hydrophobic or hydrophilic; b) patterning the substrate surface to create a surface wettability pattern on the substrate surface, the surface wettability pattern comprising a two-dimensional array of spaced apart hydrophilic microdomains and at least one hydrophobic zone separating the hydrophilic microdomains; c) coating the two-dimensional array with a hydrophilic liquid capable of forming a scratch-resistant coating in a dried and / or cured state to form spaced apart droplets of the hydrophilic liquid that are anchored to the hydrophilic microdomains by their wettability; d) drying and / or curing (e.g., UV or thermal curing) the spaced apart droplets of hydrophilic liquid to produce therefrom a three-dimensional array of microlenses forming at least one microstructured surface; Includes.

[0012] It should be noted that this "post-manufacturing" according to the present invention of an array of microlenses on the anterior and / or posterior major surfaces of an ophthalmic article by adding a scratch-resistant coating in steps c) and d) is fully compliant with prescription and technical standards.

[0013] It should also be noted that the manufacturing method of the present invention allows for the formation of patterns of microlens arrays on existing ophthalmic articles, such as prescription lenses, without modifying the manufacturing process for lenses, which may be made of any lens material and have any geometric shape, as described above. As a result, the overall process can be advantageously carried out at a lower cost compared to existing processes, allowing for individualization of the microlenses at a later stage.

[0014] It will also be noted that a major advantage of the manufacturing method of the present invention is that the array of microlenses can be formed from any existing scratch-resistant (i.e. hard-coat) material with high mechanical resistance, and therefore these microlenses do not require any other protective layer thereon (although optionally additional layers such as anti-reflective coatings, among others, can be applied on the outer surface of the microlenses).

[0015] It will be further noted that in the case of inorganic ophthalmic substrates, the surface of the inorganic ophthalmic substrate can be rendered either hydrophobic or hydrophilic by appropriate treatment, and that steps b), c) and d) above can be applied to any inorganic or organic ophthalmic substrate in an uncoated state ("neat substrate" or modified substrate surface), provided that the ophthalmic substrate has a sufficiently high scratch resistance.

[0016] According to a first embodiment of the present invention, step a) comprises rendering an ophthalmic substrate made of an inorganic material either hydrophobic or hydrophilic on the surface of said substrate (i.e., it is not necessarily necessary to provide the ophthalmic substrate with a separate hydrophilic or hydrophilic coating in step a).

[0017] According to a second embodiment of the invention, step a) comprises providing an ophthalmic substrate made of an organic material, which is either hydrophobic or hydrophilic and has a first scratch-resistant coating defining the surface of said substrate, the scratch-resistant coating forming the microlenses after steps c) and d) therefore representing a second scratch-resistant coating.

[0018] The thickness of the first scratch-resistant coating is generally in the range of 1 micrometer to 10 micrometers, preferably 2 to 6 micrometers.

[0019] It may be noted that, although not required, such a first scratch-resistant coating may also be applied to inorganic ophthalmic substrates.

[0020] It will be further noted that, as detailed below, the three-dimensional array of microlenses obtained in step d) according to the first and second embodiments above can be removed, for example by immersion in an appropriate removal bath while protecting the first scratch-resistant coating, to selectively restore the ophthalmic substrate coated with the first scratch-resistant coating. This may advantageously allow the ophthalmic substrate provided with the first scratch-resistant coating to be recoated with another three-dimensional array of microlenses in order to modify the optical properties of the ophthalmic article according to the wearer's progression of myopia. This may also be useful when the yield is low during the creation of the first three-dimensional array of microlenses, since removal allows for a second application, which is difficult to achieve with polymer microlenses made by an injection process.

[0021] According to another feature of the above second embodiment of the present invention, in step c), the hydrophilic liquid may be selected such that the second scratch-resistant coating forming the microlenses preferably has a Bayer value equal to or greater than the Bayer value of the first scratch-resistant coating, both Bayer values ​​being measured in accordance with the ASTM F735-81 standard and preferably equal to or greater than 2, more preferably between 3 and 25, even more preferably between 4 and 15 depending on the material used for the second scratch-resistant coating.

[0022] This Bayer gradient between the first and second scratch-resistant coatings makes it possible to endow the microlenses with particularly sufficient mechanical resistance.

[0023] Advantageously, according to any of the aforementioned features of the first and second embodiments above, in step c), the hydrophilic liquid may be a polar liquid selected from a solution in a polar solvent and an emulsion comprising a polar phase.

[0024] It will be noted that these solutions or emulsions in polar solvents, which may be highly polar, comprise mixtures of highly polar liquids, and such exemplary hydrophilic liquids may contain small amounts of water.

[0025] It will also be noted that the hydrophilic liquid may further be selected to exhibit a sufficiently low viscosity and a sufficiently high surface tension to minimize viscous fluid resistance and maximize capillary forces to prevent wetting of the at least one hydrophobic zone by the hydrophilic liquid.

[0026] It will be further noted that the hydrophilic liquid composition may further be selected based on the desired refractive index for the array of microlenses.

[0027] Preferably, according to the above first and second embodiments, the hydrophilic liquid used in step c) comprises at least one inorganic oxide of a metal or a non-metal selected from colloidal silica, titania, zirconia, antimony oxide, and mixtures or composite oxides thereof, the hydrophilic liquid being selected from polar solutions comprising alcohols, ketones and / or ester solvents, the hydrophilic liquid comprising a silane or alkoxysilane hydrolysate / condensate, at least one inorganic oxide and a catalytic amount of a curing catalyst preferably selected from an aluminum-based catalyst and an organometallic complex of zirconium, titanium, iron or nickel.

[0028] Alternatively, the hydrophilic liquid composition may be free of colloidal oxide particles, in which case the hydrophilic liquid composition may essentially comprise a silane or alkoxysilane hydrolysate / condensate in a polar solvent.

[0029] More preferably, the hydrophilic liquid comprises an epoxytrialkoxysilane and a dialkyldialkoxysilane hydrolysate / condensate, colloidal silica, and a catalytic amount of a curing catalyst. Exemplary usable compositions are disclosed in French Patent No. 2702486 A1 or its equivalents, U.S. Patent Application Publication No. 2003 / 165698 A1 and International Publication No. 2020 / 078964 A1. The remainder of the hydrophilic liquid composition may consist essentially of solvents conventionally used in formulating such hydrophilic liquids. Even more preferably, the hydrolysate / condensate is a γ-glycidoxypropyltrimethoxysilane (GLYMO) and dimethyldiethoxysilane (DMDES) hydrolysate / condensate or a GLYMO and triethylorthosilicate (TEOS) hydrolysate / condensate.

[0030] Exemplary aluminum-based curing catalysts are those of the following two formulas (I) or (II): [ka] (In the formula, R and R' are linear or branched alkyl groups having 1 to 10 carbon atoms, R'' is a linear or branched alkyl group having 1 to 10 carbon atoms, a phenyl group, [ka] group, where R has the above meaning, and - n is an integer from 1 to 3 The compound may be selected from aluminum chelates or compounds having one of the following formulas:

[0031] Aluminum chelates, as is known, are compounds formed by reacting aluminum alcoholates or acylates with nitrogen- and sulfur-free sequestering agents that contain oxygen as a coordinating atom.

[0032] Preferably, the aluminum chelate has the formula (III): AlXv Y 3-v (III) (In the formula, X is an OL group, L is an alkyl group having 1 to 10 carbon atoms, Y is represented by the following formula (1) or (2): M 1 COCH2COM 2 (1) M 3 COCH2COOM 4 (2) (In the formula, M 1 , M 2 , M 3 and M 4 is an alkyl group having 1 to 10 carbon atoms, and v takes the value 0, 1, or 2. and at least one coordination product obtained from a compound having the formula The compound is selected from compounds having the formula:

[0033] Examples of compounds having formula (III) are aluminum acetylacetonate, aluminum ethylacetoacetate bisacetylacetonate, aluminum bisethylacetoacetate acetylacetonate, aluminum di-n-butoxide monoethylacetoacetate and aluminum diisopropoxide monomethylacetoacetate.

[0034] Preferred compounds having formula (I) or (II) are those in which R' is an isopropyl or ethyl group and R and R'' are methyl groups.

[0035] One or more compounds having formula (I), (II), or (III) may be used as an aluminum-based curing catalyst, which may be used in a proportion to cure the hydrophilic liquid at a temperature of around 100°C for several hours, generally 0.1% to 5% by weight of the hydrophilic liquid composition.

[0036] According to a preferred embodiment of the present invention common to the first and second embodiments described above, step c) is carried out by dip coating, by immersing the ophthalmic substrate with the patterned substrate surface (and therefore with the first scratch-resistant coating according to the second embodiment) in a bath of hydrophilic liquid and then controlling the withdrawal of the immersed ophthalmic substrate from the bath, the withdrawal being controlled to obtain the desired radius of curvature and / or volume for each of the microlenses obtained in step d). In fact, the radius of curvature of each droplet results from the volume of the droplet, which is itself directly related to the withdrawal speed, provided that this speed is lower than the critical speed. Furthermore, the volume of the droplet also depends on the dimensions of each hydrophilic microdomain formed in step b) and on the dimensions of at least one zone.

[0037] It should be noted that although this dip-coating technique is preferred for coating the two-dimensional array with the hydrophilic liquid, other coating techniques such as spin-coating, spray-coating or roll-coating may alternatively be used.

[0038] In the dip coating preferably performed in step c), the maximum allowable withdrawal speed can be determined by measuring the critical transition speed at which, after immersion and withdrawal, a film of the hydrophilic liquid is not dragged onto at least one hydrophobic zone, and controlled withdrawal of the immersed ophthalmic substrate from the bath is performed at an adjusted withdrawal speed selected to be below said critical transition speed.

[0039] According to a general feature of the invention, which may relate to any of the foregoing, including the first and second embodiments described above, in particular when step c) is carried out by dip coating, steps b) and c) are carried out in such a way that the microlenses obtained in step d) are - when the ophthalmic article is a curved prescription ophthalmic lens, at least one larger lateral dimension, such as a diameter greater than 500 μm, preferably between 1 mm and 2 mm, if the micro-lenses are designed to control the progression of myopia; and / or The shape of the resulting microlenses is not particularly limited, but may be at least one shape selected from the group consisting of spherical, cylindrical, elliptical, and combinations thereof; and / or - different refractive indices and / or different colors (and optionally haze) The eigenvalues ​​may be implemented to have the following:

[0040] It should be noted that the shape and size of the droplets deposited in step c) of the method of the present invention determine the radius and focus parameters of the array of microlenses after subsequent drying and / or hardening in step d). Indeed, the final shape of the droplets will differ from the drop shape immediately after withdrawal due to evaporation of the solvent used in the scratch-resistant coating for the droplets. Furthermore, the dry content of this coating liquid can also be a controlling parameter for the final geometry of the microlenses.

[0041] It should also be noted that variations in the conventional spherical shape of the microlenses can be easily achieved by varying the geometry of the hydrophilic microdomains in step b), including different sizes and / or shapes that can be easily combined for the resulting microlenses on the same surface in step d), resulting in, for example, astigmatic microlenses and / or microlenses with different optical powers (e.g., two types of spherical microlenses to generate two optical powers).

[0042] According to a general feature of the invention, which may relate to any of the foregoing, including the first and second embodiments above, in particular when step c) is carried out by dip coating, The ophthalmic substrate may be made of an inorganic material or an organic material that is thermoset, photocurable or thermoplastic; The method consists of the following steps A) and B): A) before step a), coating the ophthalmic substrate with a primer coating, which primer coating is itself coated with the substrate surface (i.e., coated with the first scratch-resistant coating in the second embodiment); and B) An ophthalmic substrate comprising a patterned substrate surface on an existing curved lens (e.g., based on either a thermoplastic or a thermosetting material and already provided with or without a scratch-resistant coating), - between step b) and step c), laminating an ophthalmic substrate with said substrate surface patterned according to a surface wettability pattern, or - after step d), laminating the patterned substrate surface (i.e. the patterned first scratch-resistant coating in the second embodiment) and the ophthalmic substrate comprising the three-dimensional array of microlenses; laminating by a molding technique carried out by It may further include at least one of:

[0043] In a second embodiment, between steps a) and b), lamination of the ophthalmic substrate with the first scratch-resistant coating, still unpatterned, can instead be performed as a variant of step B).

[0044] Also in relation to the second embodiment, the first scratch-resistant coating may be selected from a solution containing at least one inorganic oxide selected from metal and non-metal oxides.

[0045] Thermoplastic materials that can be used for the ophthalmic substrate include, for example, polyamides, polyimides, polysulfones, polycarbonates and their copolymers, polyethylene terephthalate, and (meth)acrylic (co)polymers, particularly polymethyl methacrylate (PMMA). Cyclic olefin copolymers (COC), cyclic olefin polymers (COP), and cellulose acetates, such as tricellulose acetate (TAC), can also be included.

[0046] Examples of thermosetting materials that can be used for ophthalmic substrates include: - homopolymers and copolymers of allyl carbonates of linear or branched aliphatic or aromatic polyols, such as homopolymer of diethylene glycol bis(allyl carbonate) (CR 39®); - homopolymers and copolymers of (meth)acrylic acid and its esters, optionally derived from bisphenol A; - homopolymers and copolymers of thio(meth)acrylic acid and its esters, optionally homopolymers and copolymers of allyl esters derived from allylic aromatic compounds such as bisphenol A or phthalic acid and styrene, - urethane and thiourethane copolymers, - Epoxy homopolymers and copolymers, and - Homopolymers and copolymers of sulfides, disulfides and episulfides may be mentioned.

[0047] Examples of substrates that may be used in the present invention include those derived from MR6®, MR7®, MR8®, MR174® and MR10® resins (thermosetting polythiourethane resins), CR39® and Trivex®.

[0048] The first scratch-resistant coating used in the second embodiment of the organic ophthalmic substrate (this coating is optional in the first embodiment of the inorganic ophthalmic substrate) can have a composition similar to that described above for the hydrophilic liquid designed to form the second scratch-resistant coating, i.e., the metal or non-metal oxide is selected from colloidal silica, titania, zirconia, antimony oxide, and mixtures thereof, and the first scratch-resistant coating is obtained from a polar solution containing an alcohol, ketone, and / or ester solvent and an epoxysilane hydrolyzate, at least one inorganic oxide, and a catalytic amount of a curing catalyst (preferably an aluminum-based curing catalyst selected from one of the formulas (I), (II), or (III) above). Nevertheless, the first scratch-resistant coating is preferably selected to exhibit a Bayer value greater than or equal to 2 and preferably less than or equal to the Bayer value of the second scratch-resistant coating, both values ​​being measured according to ASTM F735-81.

[0049] With respect to any additional steps A) and B) above, - step A) of coating the ophthalmic substrate with a primer coating having a high surface tension before step a) may make it possible to improve the adhesion of the scratch-resistant coating on some substrates and to impart impact resistance to the finished ophthalmic article; Step B) may include the case where the microlenses are made of a film obtained by the sequence of steps a) to d), which film is then laminated onto an existing ophthalmic article (e.g., laminated onto a curved prescription lens with or without a hard coat), which may optionally already be provided with a scratch-resistant coating. It may be noted that

[0050] According to another general feature of the invention, which may relate to any of the foregoing, including the first and second embodiments above, in particular when step c) is carried out by dip coating, the method comprises: e) removing the three-dimensional array of microlenses obtained in step d) by immersion in a removal bath in order to selectively restore the ophthalmic substrate comprising the substrate surface, and optionally providing said substrate surface (i.e. the first scratch-resistant coating in the second embodiment) with a protective masking means; f) first carrying out the sequence of steps c) and d) and optionally step b) at least once to obtain another three-dimensional array of microlenses forming at least one microstructured surface (indeed, step b) need not necessarily be carried out again in step f) if the removal of the microlenses results in a surface with hydrophilic properties); It may further include:

[0051] Depending on the respective compositions of the first and second scratch-resistant coatings, immersion in the removal bath may undesirably remove both coatings, as may occur in particular in the case of caustic baths (which may be used in the removal bath), and therefore it may be noted that the protective masking means is intended to protect the first scratch-resistant coating during this immersion, for example in a caustic bath, in order to remove only the second scratch-resistant coating. Nevertheless, if the first scratch-resistant coating is damaged, it may be desirable to remove both coatings. The entire process can then be carried out again.

[0052] It may also be noted that said protective masking means may be retained for subsequent application of another array of microlenses in step f).

[0053] According to another general feature of the present invention, which may relate to any of the foregoing, including the above first and second embodiments, particularly when step c) is performed by dip coating, step a) may be performed by using an ophthalmic lens selected from a finished ophthalmic lens and an optionally edged ophthalmic lens blank, preferably a curved prescription ophthalmic lens, as an ophthalmic substrate comprising said substrate surface (i.e. the first scratch-resistant coating in the second embodiment).

[0054] According to another general feature of the present invention, which may relate to any of the foregoing, including the first and second embodiments above, in particular when step c) is performed by dip coating, step b) may be performed by a mask-assisted or maskless technique selected from chemical etching, laser ablation or etching (in maskless laser etching, the pattern is digitally formed by laser scanning of the surface), low pressure or atmospheric pressure plasma or corona etching, UV or ozone etching and reactive ion etching (RIE), chemical grafting of molecules having hydrophilic or hydrophobic functional groups, to create hydrophilic microdomains and at least one hydrophobic zone on the substrate surface (i.e. on the first scratch-resistant coating in the second embodiment).

[0055] Step b) is a mask-assisted technique, (i) patterning the substrate surface (i.e. the first scratch-resistant coating in the second embodiment) selected to be hydrophobic by chemical etching techniques, preferably assisted by a flexible mask applied under pressure onto the substrate surface; or (ii) in step a), previously providing a substrate surface (i.e., the first scratch-resistant coating in the second embodiment) having an outer surface that is either already hydrophilic or is made hydrophilic between steps a) and b), and in step b), creating at least one hydrophobic zone via the mask-assisted technique by treating the unmasked areas with the molecules having hydrophobic functional groups; This can be implemented by a mask-assisted technique using

[0056] Alternatively, step b) may be preferably carried out by maskless surface ablation techniques using power laser scanning (e.g. excimer laser with picosecond or femtosecond techniques) or maskless techniques (such as photolithography) instead of techniques using contact or projection image masks.

[0057] More preferably, according to the second embodiment, step b) is carried out in case (i) by providing a flexible mask having an array of through-holes, optionally with different shapes and / or dimensions, preferably with a diameter of 1 mm to 2 mm, and immersing the first scratch-resistant coating in a caustic bath of NaOH or KOH; and In case (ii), the outer surface of the first scratch-resistant coating is advantageously subjected to the following treatment between steps a) and b): at least one of chemical etching, laser ablation or etching, low-pressure or atmospheric plasma or corona etching, UV or ozone etching and reactive ion etching (RIE) and chemical grafting of molecules with hydrophilic functional groups, or depositing on the first scratch-resistant coating layer a hydrophilic layer comprising at least one inorganic oxide of a metal or non-metal selected from silica, titania, zirconia, antimony oxide and mixtures thereof; can be made hydrophilic by

[0058] In the above case (ii), the same pattern of hydrophilic micro-domains and hydrophobic zones are formed starting from the hydrophobic first scratch-resistant coating, - first using a hydrophilic material for the first scratch-resistant coating, or - mask-assisted or maskless techniques selected from chemical etching, laser ablation or etching, low-pressure or atmospheric plasma or corona etching, UV or ozone etching, RIE and chemical grafting of molecules with hydrophilic functional groups, or adding said hydrophilic layer, for example of silica or titanium oxide It may be noted that this may be formed, for example, by using an outer surface of the first scratch-resistant coating that is completely hydrophilic or by making the outer surface of the first scratch-resistant coating completely hydrophilic.

[0059] Therefore, the above case (ii) can be useful when the first scratch-resistant coating is not sufficiently hydrophobic, for example, according to the above case (i), so that sufficient wettability contrast cannot be created between the hydrophilic microdomains and at least one hydrophobic zone. Alternatively, the case (i) can be implemented by first adding a specific highly hydrophobic coating to the slightly hydrophobic first scratch-resistant coating in step a), so that the wettability contrast is increased in step b).

[0060] An ophthalmic article according to the present invention is obtainable by the method defined above, wherein the ophthalmic article has a front major surface and a rear major surface, at least one of which is a microstructured surface, and wherein the ophthalmic article comprises: - an ophthalmic substrate, preferably organic, comprising a patterned substrate surface (i.e. the first scratch-resistant coating in the second embodiment) patterned according to a surface wettability pattern comprising hydrophilic microdomains spaced apart from one another and at least one hydrophobic zone separating the hydrophilic microdomains from one another; a three-dimensional array of microlenses forming at least one microstructured surface and respectively attached only to the hydrophilic microdomains, the microlenses being based on a scratch-resistant coating coating the patterned substrate surface; Includes.

[0061] When the ophthalmic substrate is made of the organic material according to the second embodiment, the substrate surface is defined by a first scratch-resistant coating that is patterned according to the surface wettability pattern, and the scratch-resistant coating forms a second scratch-resistant coating that coats the patterned first scratch-resistant coating, preferably having a Bayer value equal to or greater than the Bayer value of the first scratch-resistant coating, both Bayer values ​​being measured according to the ASTM F735-81 standard.

[0062] Advantageously, the ophthalmic article comprises: - ophthalmic lenses, including finished ophthalmic lenses and optionally edged ophthalmic lens blanks, preferably curved prescription lenses for controlling myopia progression, wherein the microlenses have at least one shape selected from spherical, cylindrical, elliptical and combinations thereof and at least one larger lateral dimension, such as a diameter, greater than 500 μm, preferably between 1 mm and 2 mm; and - Smart Eyewear Devices may be selected from:

[0063] As explained above, ophthalmic articles according to the present invention, such as ophthalmic lenses for eyeglasses, may include microlenses that may have different refractive indices and / or different colors, may optionally be hazy, and may be variously coated, such as at least one coating selected from an antireflective coating, an antistatic coating, a conductive coating, an anti-fog coating, an anti-fouling coating, a photochromic coating, an electrochromic coating, a polarizing coating, and combinations thereof.

[0064] It will be noted that the ophthalmic article may be usable not only as a corrective lens usable to treat or control myopia, but also to treat or control hyperopia, astigmatism and / or presbyopia. [Brief explanation of the drawings]

[0065] [Figure 1]1 is a schematic side view of a hydrophilic microdomain illustrating the theory of complete wetting of the domain by a hydrophilic liquid. [Figure 2] FIG. 1 is a schematic side view of a partially hydrophobic zone illustrating the theory of partial wetting of a zone by a hydrophilic liquid by showing the contact angle θ as a function of the solid-gas, solid-liquid, and liquid-gas interfacial energies γ, γ, and γ, respectively. [Figure 3] FIG. 1 is a schematic side view of a highly hydrophobic zone illustrating poor wetting of the zone by hydrophilic liquids, as indicated by a contact angle of greater than 90°. [Figure 4] 1 is a schematic side view of a surface wettability pattern according to the present invention, comprising a two-dimensional array of hydrophobic zones and hydrophilic microdomains covered with a hydrophilic liquid that forms spaced apart droplets that are anchored to the hydrophilic microdomains by its complete wetting. [Figure 5] 1 is a schematic top view of a droplet of hydrophilic liquid surrounded by a hydrophobic zone, the droplet configured to form an asymmetric microlens. [Figure 6] 1 is a diagrammatic representation for calculating the sag of a hemispherical microlens for controlling myopia, which may be formed in accordance with the present invention, based on the radius of curvature R and diameter d of the microlens. [Figure 7] 3 is a diagrammatic representation for visualizing and measuring the advancing and receding contact angles θa and θr when performing the dip-coating technique in step c) of the manufacturing method of the present invention, showing three states a to c. [Figures 8a-8c] Figures 8a to 8c show schematically three different regimes that emerge when the withdrawal speed U from the dip coating bath is successively increased, only Figure 8a, where U is below the critical speed Uc, is in accordance with the present invention. [Figure 9] 1 is a diagrammatic representation showing an exemplary embodiment of the implementation of steps a) and b) of the method of the present invention, which is applied to a hydrophobic first scratch-resistant coating with a mask-assisted etching technique to obtain a surface wettability pattern comprising a two-dimensional array. [Figure 10]10 is a diagrammatic representation showing an exemplary embodiment of the implementation of step c) of the method of the invention by dip-coating and withdrawing the two-dimensional array obtained in FIG. 9 into a hydrophilic liquid. [Figure 11] Photograph of a mask made of flexible plastic film with a pattern of micro-holes that can be used in the mask-assisted etching technique of step b), which is laminated to a flat lens. [Figure 12] Photograph of another mask made of flexible plastic film with a pattern of micro-holes that can be used in the mask-assisted etching technique of step b), which is laminated onto the curved surface of the ophthalmic lens blank. [Figure 13] 1 is a photograph of a curved ophthalmic lens incorporating a three-dimensional array of microlenses obtained by the mask and method according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0066] As used herein, the terms "comprise" (and its grammatical variants such as "comprises" and "comprising"), "have" (and its grammatical variants such as "has" and "having"), "contain" (and its grammatical variants such as "contains" and "containing"), and "include" (and its grammatical variants such as "includes" and "comprising") are open-ended linking verbs. They are used to specify the presence of stated features, integers, steps, or components or groups thereof, but do not exclude the presence or addition of one or more other features, integers, steps, or components or groups thereof. Consequently, a method or step in a method that "comprises," "has," "contains," or "includes" one or more steps or elements is not limited to having only those one or more steps or elements.

[0067] Unless otherwise specified, all numbers or expressions relating to amounts of ingredients, ranges, reaction conditions, etc. used herein are understood to be modified in all cases by the term "about." Unless otherwise specified, in accordance with the present invention, expressions relating to intervals of values, such as "X to Y" or "between X and Y," also mean to include the values ​​of X and Y.

[0068] Full and partial wettability of hydrophilic and hydrophobic regions / zones on surfaces As shown in Figures 1 and 2, a hydrophilic liquid that completely (Figure 1) or partially (Figure 2) covers a wettable area can be thermodynamically described by a wetting parameter S, where S = γ SG -γ LG -γ LS (where γ SG , γ LS and γ LG represent the solid-gas, solid-liquid, and liquid-gas interfacial energies, respectively).

[0069] When S>0, which is complete wetting in Figure 1, the liquid spreads completely on the surface and the macroscopic contact angle is equal to 0, whereas when S<0, which is partial wetting in Figure 2, the liquid only spreads partially on the surface and forms droplets with a macroscopic contact angle θ less than 90°. The macroscopic contact angle θ is a general indicator of the surface ability to be partially or completely wetted by a liquid, and the wetting parameter S depends only on the interfacial surface energy of the system.

[0070] A surface is said to be hydrophilic if the contact angle is less than 90°, preferably less than 80°, more preferably less than 70°, and is said to be almost completely wettable if the contact angle is, for example, less than 20°, which is the case for each hydrophilic microdomain patterned in step b) and coated in step c) according to the method of the present invention.

[0071] If the contact angle is greater than 90°, the surface is said to be non-wettable (i.e., hydrophobic), although physically partially wettable (ultra-hydrophobic or non-wettable surfaces typically have contact angles greater than 120°), which is the case for at least one hydrophobic zone interconnecting the hydrophilic microdomains, as shown in Figure 3.

[0072] 4 shows an exemplary surface wettability pattern obtained in step b) according to the present invention, which pattern comprises spaced apart hydrophilic microdomains 1, each configured to form a droplet D after step c), and at least one hydrophobic zone 2 interconnecting the hydrophilic microdomains 1 to form a two-dimensional array 3 and resulting pattern. As the volume of each droplet D increases, the contact line approaches a critical contact angle θ at which the droplet D begins to spread beyond the boundary. c is blocked by the hydrophilic boundary between microdomain 1 and zone 2 until

[0073] This limiting contact angle θ c gives the maximum radius of curvature of each microlens considering the base diameter for each droplet D and assuming a perfect spherical shape.

[0074] The basal diameter of the droplet is the capillary radius l c If the distance between the droplets D and the surface of the liquid is less than twice the distance between the droplets D and the surface of the liquid, the shape of each droplet D is not affected by gravity.

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[0075] The capillary radius is generally about 1 mm, and the droplet diameter according to the present invention is less than 2 mm if the droplet is spherical, since the shape is governed by capillary forces. Droplet diameters greater than 2 mm may be slightly flattened by gravity and are therefore not preferred according to the present invention.

[0076] Dynamic droplet formation by dip coating technology The formation of droplets on the surface wettability pattern 3 obtained in step b) (comprising hydrophilic microdomains 1 and at least one hydrophobic zone 2 on the first scratch-resistant coating) occurs when this pattern 3 is lifted from the bath of hydrophilic liquid, after which at least one hydrophobic zone 2 remains dry and the droplets D are finally fixed to the hydrophilic microdomains 1.

[0077] In the partially wettable zone (hydrophobic zone 2, hence S<0), the maximum speed of lift is related to the transition speed U. If the viscous drag force is greater than the capillary force, the contact line is no longer stable and the metastable film that forms can lead to uncontrolled dewetting from the hydrophobic zone. This situation, which is uncontrollable and does not provide sufficient control over the droplet volume uniformity, is avoided in the present invention, as explained below.

[0078] To perform step c) of the method of the present invention, the advancing and receding contact angles during dip coating (which are different and whose difference defines the contact angle hysteresis) are considered and measured as illustrated in Figure 7. Specifically, dip coating involves a receding contact angle, which is measured with common equipment (e.g., a needle as seen in both of the middle figures in Figure 7 or a tilt technique as seen in the bottom figure c in Figure 7).

[0079] This contact angle should be high enough to leave the hydrophobic zones completely unwetted after slow withdrawal of the patterned surface 3 from a bath of hydrophilic liquid. Indeed, for partially wetting liquids, two regimes exist, depending on the physical phenomena due to complex fluid dynamics: - if the surface 3 is completely dry, the liquid film is not drawn to the surface, or The surface 3 draws the liquid away and then either forms an undesirably continuous film or breaks up into small droplets.

[0080] According to the present invention, in order to reliably form an array of microlenses in steps c) and d), the partially wettable portions (i.e., hydrophobic zones 2) must remain dry after dip-coating, and the inventors have confirmed that this occurs only below a determined transition rate that is not easily predictable but is easily measured.

[0081] Qualitatively, the inventors have determined that the higher the contact angle on the partially wettable portion or hydrophobic zone 2, the higher the allowable lift-off transition speed. For productivity, a high contact angle (greater than 70°, preferably greater than 80°, more preferably greater than 90°, and even more preferably equal to or greater than any of the following values ​​95° and 100°) is preferred, but is not absolutely required for the hydrophobic zone 2.

[0082] Because the liquid film formed only locally on the surface of the wettable regions, the withdrawal rate determined the amount of liquid left behind at these fully wetted spots (hydrophilic microdomains 1).

[0083] Returning to Figure 4, assuming a zero contact angle on the wettable hydrophilic microdomains 1, the maximum droplet size is limited by the advancing and receding contact angles at the partially wettable portions (hydrophobic zones 2) of the patterned surface 3.

[0084] The larger the contact angle between the liquid and the solid in the partially wettable hydrophobic zone 2, the smaller the minimum droplet radius.

[0085] Maximum droplet contact angle θ c was the advancing contact angle for the partially wettable region of the lens surface. c If the droplet D is significantly larger than 1000 Å, the droplet D will spread over the partially wettable zone 2, which is undesirable for the method of the present invention.

[0086] As can be seen in Figure 8, if the pull rate is too high, excess liquid remains on the surface 3, which does not meet the above criteria for droplet stability.

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[0087] This number compares viscous drag forces with surface tension forces.

[0088] As shown in the left panel of Figure 8, below the critical transition velocity U, the partially wettable hydrophobic zone 2 remained dry, the liquid was not dragged onto zone 2, and the contact line was stable, which was the only example of well-controlled lifting according to the present invention.

[0089] As shown in the right panel of Figure 8, above the critical transition velocity U, the contact line rose significantly, resulting in an undesirable dragging of the liquid layer on the surface.

[0090] Finally, the hydrophilic liquid droplets D adhered well only to the hydrophilic microdomains 1 with the highest solid / liquid interfacial energy (with wetting parameter S > 0) (fully wettable). Here, a higher pulling speed resulted in a larger volume and a smaller radius of curvature for each droplet D.

[0091] Microstructured Surface of Ophthalmic Articles According to the Invention Herein, the microstructured surface forming the front and / or rear major surfaces of the ophthalmic substrate 10 comprising the first scratch-resistant coating comprises lenslets in the form of microlenses that form convex portions separated by concave portions at the major surfaces on which they are disposed. The outer shape of the lenslets may be round or polygonal, e.g., circular, elliptical, or hexagonal, although any outer shape may be envisioned for the droplets D, and the microlenses may be spherical, toric, or aspherical, rotationally symmetric (i.e., axisymmetric or non-axisymmetric), although any shape may also be envisioned for the microlenses. Each microlens may have a single focal or cylindrical power, or no focal point.

[0092] In the exemplary embodiment of Figure 5, which illustrates a non-circular boundary for droplet D, capillary forces cause the droplet surface to assume a shape that minimizes its air / surface area, i.e., an elliptical profile (approximating a toric surface if the radii are small enough) that defines a semi-elliptical shape with two different orthogonal radii or curvatures in this example. This semi-elliptical shape forms two focal points. These profiles and shapes may be numerically calculable, and this boundary condition may be precisely controlled by the methods of the present invention.

[0093] In preferred embodiments, lenslets or microlenses can be used to prevent the progression of myopia or hyperopia, where the base lens substrate comprises a base lens that provides optical power to correct myopia or hyperopia, and the microlenses or lenslets can provide optical power greater than that of the base lens when the wearer is myopic, or less than that of the base lens when the wearer is hyperopic, respectively.

[0094] When the microlenses are designed to control the progression of myopia, the lenslets may have a contour shape that can be inscribed in a circle having a diameter of 500 μm or more, preferably 1 mm to 2 mm.

[0095] The lenslets may have a height, measured in a direction perpendicular to the major surface on which they are disposed, that is greater than or equal to 0.1 μm and less than or equal to 50 μm.

[0096] The major surface may be defined as a surface that may be planar, spherical, spherocylindrical, or even a complex surface that includes the center points of all microstructures. This major surface may be a virtual surface if the microstructures are embedded in the lens, or may be close to or identical to the physical outer surface of the ophthalmic lens if the microstructures are not embedded. The height of the microstructures may therefore be determined using an axis locally perpendicular to this major surface by calculating, for each point of the microstructure, the difference between the maximum positive deviation minus the minimum negative deviation relative to the major surface along the axis.

[0097] The lenslets may have a periodic or quasi-periodic layout, but may also be arranged at random locations. Exemplary layouts for the lenslets may be a lattice with a constant lattice spacing, a honeycomb layout, multiple concentric circles, or a continuous arrangement with no gaps between the microstructures, for example.

[0098] These structures can provide optical wavefront modification in intensity, curvature, or light deflection, where wavefront intensity is configured such that the structures can be absorptive and can locally absorb wavefront intensity in the range of 0% to 100%, curvature is configured such that the structures can locally modify wavefront curvature in the range of + / - 20 diopters, and light deflection is configured such that the structures can locally scatter light at angles in the range of + / - 1° to + / - 30°.

[0099] The distance between structures can range from 0 (continuous) to 3 times the structure (separate microstructures).

[0100] As seen in FIG. 6, the method of the present invention for manufacturing an ophthalmic article for controlling the progression of myopia with a three-dimensional array of microlenses used microlenses having a diameter d of about 1-2 mm and an optical power of 3 diopters.

[0101] The sag (also called "arrow") of a microlens is given by the well-known formula: SAG=R-√(R 2 -(d / 2) 2 (wherein R represents the radius of curvature and d represents the diameter) It can be calculated from

[0102] The sag was at most a few microns, and the contact angle of the droplet was very small. At small angles, tan θ ~ θ, so θ was close to a few mrad (1 mrad is approximately 0.06°). This angle was so small that this factor was found to be non-limiting in practice. [Example]

[0103] The following examples illustrate the invention in more detail but are not limiting.

[0104] Process carried out for dip coating of surface wettability patterns As explained above, to limit viscous drag and maximize capillary forces, the surface wettability pattern was immersed in a hydrophilic liquid, preferably of low viscosity and high surface tension, and the partially wettable surface defined by hydrophobic zone 2 was inhibited from being wetted by the liquid (the hydrophilic liquid was repelled).

[0105] The volume of each resulting droplet was so small that dilution of the coating material actually allowed for good control of the final volume of droplet D and the resulting microlens after evaporation of the solvent. The solvent was chosen to reduce the viscosity of the hydrophilic liquid and increase its surface tension, thereby promoting very low fluid resistance. For the solvent-based hydrophilic coatings tested, subsequent drying caused droplet D to change slightly in volume, becoming more flattened (and thus causing a change in radius of curvature), but this change was easily predicted.

[0106] After slowly withdrawing the surface wettability pattern from the hydrophilic bath, the withdrawal speed was increased slightly and the transition withdrawal speed (where the liquid (film or droplet) was not withdrawn from the partially wettable surface) was measured. This was done on an unpatterned surface, but preferably the transition withdrawal speed should also be measured on an actual surface wettability pattern.

[0107] This transition speed value was the limiting maximum withdrawal speed for the dip-coating process, i.e., the critical transition speed at which the liquid begins to adhere only to the fully wettable hydrophilic microdomains 1. The withdrawal speed and dry content of the liquid were adjusted accordingly to obtain the desired droplet and microlens height after solvent evaporation and drying / hardening. The actual withdrawal speed never exceeded the critical speed thus measured.

[0108] The three-dimensional array of microlenses obtained in step d) can be dried and then cured, if desired, for example by UV radiation or heat.

[0109] Exemplary implementations of steps a), b), c) and d) thereon A 90 μm thick vinyl stencil-type masking film was cut into a hole pattern that represented the final microlens array in two dimensions (see the photograph in Figure 11). The holes had a diameter of 1 mm to 2 mm, in view of the ophthalmic design to be manufactured. The following main steps were then performed:

[0110] The masking film was then cold pressed onto a major surface of a curved ophthalmic lens consisting of a CR 39® lens substrate with a first scratch-resistant coating that defined this major surface, which was hydrophobic (see Figure 12). The first scratch-resistant coating used in the first and second experiments was that disclosed in Example 3 of French Patent No. 2 702 486 A1 (or its equivalent, US Patent Application Publication No. 2003 / 165698 A1), and exhibited a Bayer value of 2 to 4, measured according to the ASTM F735-81 standard.

[0111] The low modulus of the masking film facilitated this pressing operation, but slight heating with hot air could also be used to prevent wrinkling.

[0112] A second film was applied to the other major surface of the ophthalmic substrate opposite the first scratch-resistant coating to protect the substrate from subsequent chemical treatments.

[0113] The entire lens thus protected was then immersed in a bath of the mildly etching caustic chemical NaOH (alternatively, KOH was used in other experiments) for mild chemical etching of the surface of the first scratch-resistant coating. The lens was then washed and the second film was removed. The purpose of the caustic etching was to remove the fluorinated surfactant present on the surface of the first scratch-resistant coating and to create a surface wettability pattern, achieved in step b) of the method of the present invention, having a two-dimensional array of hydrophilic microdomains 1 obtained by this caustic etching through the holes in the masking film and hydrophobic zones 2 (not treated with caustic etching) interconnecting the microdomains 1.

[0114] The lens was then immersed in a bath of a hydrophilic liquid designed to form a second scratch-resistant coating, which was approximately the same as the formulation of the first scratch-resistant coating, except that the hydrophilic liquid did not contain any surfactants (whereas the first scratch-resistant coating contained a fluorinated surfactant to enhance its wetting on the substrate).

[0115] As explained above, the hydrophilic liquid was withdrawn from the liquid bath at a rate below the critical withdrawal speed so that the liquid did not wet the hydrophobic zones 2 and adhered only to the hydrophilic microdomains 1. A three-dimensional array of microlenses was then spontaneously formed, followed by drying and curing. The second scratch-resistant coating had a Bayer value of 2-4 as measured according to the ASTM F735-81 standard.

[0116] FIG. 13 shows a photograph of an ophthalmic lens incorporating a three-dimensional array of microlenses obtained by the method of the present invention.

Claims

1. 1. A method of manufacturing an ophthalmic article having a front major surface and a rear major surface, at least one of which is a microstructured surface, comprising: a) providing an ophthalmic substrate (10) having a substrate surface that is either hydrophobic or hydrophilic; b) patterning the substrate surface to create a surface wettability pattern thereon comprising a two-dimensional array (3) of spaced apart hydrophilic microdomains (1) and at least one hydrophobic zone (2) separating said hydrophilic microdomains (1); c) coating said two-dimensional array (3) with a hydrophilic liquid capable of forming a scratch-resistant coating in a dried and / or cured state to form spaced apart droplets (D) of said hydrophilic liquid that are anchored to said hydrophilic microdomains (1) by their wettability; d) drying and / or hardening the spaced apart droplets (D) of the hydrophilic liquid to produce therefrom a three-dimensional array of microlenses forming the at least one microstructured surface; A method comprising:

2. 10. The method of claim 1, wherein step a) comprises rendering the ophthalmic substrate (10) made of inorganic material either hydrophobic or hydrophilic on the substrate surface.

3. 2. The method of claim 1, wherein step a) comprises providing the ophthalmic substrate (10) made of an organic material, the ophthalmic substrate (10) being either hydrophobic or hydrophilic and having a first scratch-resistant coating defining the substrate surface, and wherein preferably in step c) the hydrophilic liquid is selected such that the scratch-resistant coating forming the microlenses or a second scratch-resistant coating has a Bayer value equal to or greater than the Bayer value of the first scratch-resistant coating, both Bayer values ​​being measured in accordance with the ASTM F735-81 standard and preferably equal to or greater than 2.

4. 4. The method according to any one of claims 1 to 3, wherein in step c) the hydrophilic liquid is a polar liquid selected from a solution in a polar solvent and an emulsion comprising a polar phase.

5. 5. The method of claim 4, wherein in step c), the hydrophilic liquid comprises at least one inorganic oxide of a metal or a non-metal selected from colloidal silica, titania, zirconia, antimony oxide, and mixtures thereof, and the hydrophilic liquid is selected from polar solutions comprising alcohol, ketone, and / or ester solvents, and the hydrophilic liquid comprises an epoxy silane hydrolyzate, the at least one inorganic oxide, and a catalytic amount of an aluminum-based curing catalyst.

6. 6. The method according to any one of claims 1 to 5, wherein step c) is performed by dip-coating by immersing the ophthalmic substrate (10) with the substrate surface after patterning in a bath of the hydrophilic liquid and then controlling the withdrawal of the immersed ophthalmic substrate (10) from the bath, the withdrawal being controlled to obtain a desired radius of curvature and / or volume for each of the microlenses obtained in step d).

7. In the dip coating step c), the maximum allowable withdrawal speed is determined by measuring the critical transition speed at which, after immersion and withdrawal, a film of the hydrophilic liquid is not dragged onto the at least one hydrophobic zone (2), 7. The method of claim 6, wherein the controlled withdrawal of the immersed ophthalmic substrate (10) from the bath is performed at a regulated withdrawal rate selected to be equal to or less than the critical transition rate.

8. 8. The method according to claim 6 or 7, wherein steps b) and c) are carried out such that when the ophthalmic article is a curved prescription ophthalmic lens, the microlenses obtained in step d) have at least one larger lateral dimension, such as a diameter, of more than 500 μm, preferably between 1 mm and 2 mm, if the microlenses are designed to control the progression of myopia.

9. the ophthalmic substrate (10) is made of an inorganic material or an organic material that is thermosetting, photocurable or thermoplastic; said method comprising steps A) and B): A) prior to step a), coating the ophthalmic substrate (10) with a primer coating, the primer coating itself comprising the substrate surface; and B) placing the ophthalmic substrate with the patterned substrate surface on an existing curved lens; - between steps b) and c), laminating said ophthalmic substrate (10) with said substrate surface patterned according to said surface wettability pattern (3), or - after step d), laminating said ophthalmic substrate (10) comprising said patterned substrate surface and said three-dimensional array of microlenses; laminating by a molding technique carried out by The method of any one of claims 1 to 8, further comprising at least one of:

10. e) removing the three-dimensional array of microlenses obtained in step d) by immersion in a removal bath in order to selectively restore the ophthalmic substrate (10) comprising the substrate surface, and optionally providing the substrate surface with a protective masking means; f) performing the sequence of steps b), c) and d) at least once to obtain another three-dimensional array of microlenses forming said at least one microstructured surface; The method of any one of claims 1 to 9, further comprising:

11. 11. The method according to any one of claims 1 to 10, wherein step a) is performed by using an ophthalmic lens selected from finished ophthalmic lenses and optionally edged ophthalmic lens blanks, preferably curved prescription ophthalmic lenses, as the ophthalmic substrate (10) comprising the substrate surface.

12. 12. The method according to any one of claims 1 to 11, wherein step b) is carried out by a mask-assisted or maskless technique selected from chemical etching, laser ablation or etching, low pressure or atmospheric plasma or corona etching, UV or ozone etching, reactive ion etching (RIE) and chemical grafting of molecules with hydrophilic or hydrophobic functional groups to create the hydrophilic microdomains (1) and the at least one hydrophobic zone (2) on the substrate surface.

13. Step b) is performed by a mask-assisted technique, (i) patterning the substrate surface, which is selected to be hydrophobic, by chemical etching techniques, preferably assisted by a flexible mask (20) applied under pressure onto the substrate surface; or (ii) in step a) providing in advance the substrate surface having an outer surface that is either already hydrophilic or that is made hydrophilic between steps a) and b), and in step b) creating the at least one hydrophobic zone (2) via the mask-assisted technique by treating unmasked areas with the molecules having hydrophobic functional groups; The method of claim 12, wherein the method is performed by

14. Step a) comprises providing the ophthalmic substrate (10) made of an organic material that is hydrophobic and has a first scratch-resistant coating defining the substrate surface; Step b) is carried out in case of (i) by providing said flexible mask (20) with an array of through-holes, optionally with different shapes and / or sizes, preferably with a diameter of 1 mm to 2 mm, and immersing said first scratch-resistant coating in a caustic bath of NaOH or KOH; In case (ii), the outer surface of the first scratch-resistant coating is subjected to the following steps between steps a) and b): at least one of chemical etching, laser ablation or etching, low pressure or atmospheric plasma or corona etching, UV or ozone etching and reactive ion etching (RIE) and chemical grafting of molecules with hydrophilic functional groups, or depositing on said first scratch-resistant coating a hydrophilic layer comprising at least one inorganic oxide of a metal or non-metal selected from silica, titania, zirconia, antimony oxide and mixtures thereof; The method of claim 13 wherein the surface is rendered hydrophilic by

15. An ophthalmic article obtainable by the method of any one of claims 1 to 14, having a front major surface and a rear major surface, at least one of which is a microstructured surface; and an ophthalmic substrate (10) comprising a patterned substrate surface patterned according to a surface wettability pattern (3) comprising hydrophilic microdomains (1) spaced apart from one another and at least one hydrophobic zone (2) separating said hydrophilic microdomains (1); a three-dimensional array of microlenses forming said at least one microstructured surface and respectively attached only to said hydrophilic microdomains (1), said microlenses being based on a scratch-resistant coating coating said patterned substrate surface; wherein, when the ophthalmic substrate (10) is made of an organic material, the substrate surface is defined by a first scratch-resistant coating that is patterned according to the surface wettability pattern (3), and the scratch-resistant coating is a second scratch-resistant coating that coats the patterned first scratch-resistant coating, preferably the second scratch-resistant coating having a Bayer value equal to or greater than the Bayer value of the first scratch-resistant coating, both Bayer values ​​being measured in accordance with the ASTM F735-81 standard.

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