Method for obtaining an ophthalmic lens comprising a surface utility microstructure and resulting ophthalmic lenses

Abstract

The invention concerns a method for obtaining an ophthalmic lens comprising a surface utility microstructure, in particular antiglare. The method for obtaining an ophthalmic lens comprising a surface utility microstructure consists in a step for transferring the microstructure into the lens surface from a mould whereof the internal surface bears the microstructure and has a sight correcting geometric design, the microstructure being initially determined by an interferential process. The invention is useful for making ophthalmic lenses.

1 . Process for producing an ophthalmic lens comprising a surface antiglare utility microstructure, said process comprising a step for transferring the microstructure in a surface of the lens from a mould an internal surface of which supports the microstructure and has a sight-correcting geometry, the microstructure geometry being initially determined by an interferential process.  
     
     
         2 . Process according to  claim 1 , wherein the microstructure geometry is periodical.  
     
     
         3 . Process according to  claim 2 , wherein the periodical microstructure has a period comprised between 100 and 300 nm.  
     
     
         4 . Process according to any of  claims 1  to  3 , wherein the sight-correcting geometry surface is a progressive geometry surface.  
     
     
         5 . Process according to any of  claims 1  to  4 , wherein the bending radius of the surface is comprised between 40 and 100 nm.  
     
     
         6 . Process according to any of  claims 1  to  5 , wherein the mould is an integral mould and the microstructure is formed directly on the mould internal surface with the correcting geometry.  
     
     
         7 . Process according to  claim 6 , wherein the mould is formed with plastic, metal or mineral glass.  
     
     
         8 . Process according to any of  claims 1  to  5 , wherein the mould is a composite mould having at least two layers one of which supports at the surface thereof the utility microstructure.  
     
     
         9 . Process according to any of  claims 1  to  5 , wherein the microstructure is formed on one face with an insert, said insert suiting to the mould surface having the sight-correcting geometry.  
     
     
         10 . Process according to  claim 9 , wherein the insert has a shape corresponding to this of the sight-correcting geometry surface of the mould and is secured with this surface.  
     
     
         11 . Process according to  claim 9 , wherein the insert has an initially plane shape and is distorted to suit to the correcting geometry surface of the mould.  
     
     
         12 . Process according to  claim 10  or  11 , wherein the insert is secured with the correcting geometry surface of the mould through an adhesive.  
     
     
         13 . Process according to  claim 8 , wherein the microstructured layer is formed by application of a material layer onto the correcting geometry surface of the mould, said material being adapted to allow the development of a microstructure on its surface opposed to the correcting geometry surface of the mould.  
     
     
         14 . Process according to any of preceding claims, wherein the ophthalmic lens is obtained by casting into the mould of a composition of optical monomers that are thermosettable and/or can be hardened by an actinic radiation.  
     
     
         15 . Process according to any of  claims 1  to  14 , wherein the ophthalmic lens is obtained by injection into the mould of a settable optically transparent thermoplastic material.  
     
     
         16 . Process according to any of  claims 9  to  12 , wherein the microstructure is formed on a face with a deformable plane insert, said insert being distorted in the mould to suit to the correcting geometry surface of the mould.  
     
     
         17 . Process according to  claim 16 , wherein the insert is distorted in the mould by creation of a vacuum on a face of the insert opposed to the insert face supporting the utility microstructure.  
     
     
         18 . Process according to  claim 16 , wherein the insert is distorted in the mould by creation of a pressure on the insert face supporting the utility microstructure.  
     
     
         19 . Process according to  claim 18 , wherein the pressure is the casting pressure of a composition of optical monomers.  
     
     
         20 . Process according to  claim 18 , wherein the pressure is the injection pressure of an optical thermoplastic material.  
     
     
         21 . Process according to any of  claims 1  to  5 , wherein the transfer step for the utility microstructure is carried out by die-stamping of a layer of an optical composition that is thermosettable and/or settable with an actinic radiation.  
     
     
         22 . Process according to any of  claims 1  to  5 , wherein the transfer step for the utility microstructure is carried out by overmoulding a layer of an optical composition or material that is thermosettable and/or settable with an actinic radiation, onto an ophthalmic lens preform.  
     
     
         23 . Process according to  claim 22 , wherein the overmoulding consists in casting a composition of optical monomers into the mould containing the preform.  
     
     
         24 . Process according to  claim 22 , wherein the overmoulding consists in injecting an optical thermoplastic material into the mould containing the preform.  
     
     
         25 . Process according to any of  claims 1  to  5 , wherein the transfer step consists in: 
 forming in the mould a layer of a first optical material a surface of which supports a replica of the utility microstructure supported by the internal face of the mould,  
 hardening the layer of the first optical material in the mould,  
 introducing between the surface of the hardened layer of the first optical material opposed to the surface supporting the microstructure and a mould wall, a second settable optical material,  
 hardening the second optical material, and  
 dismantling the mould to recover an ophthalmic lens comprising a substrate formed with the second optical material a surface of which is covered with the hardened layer of the first optical material supporting the utility microstructure.  
 
     
     
         26 . Process according to  claim 25 , wherein the layer of the first settable optical material is obtained by applying a liquid composition of optical monomers onto the mould.  
     
     
         27 . Process according to  claim 24  or  25 , wherein the layer of the first settable optical material is formed by injection of a thermoplastic material.  
     
     
         28 . Process according to any of  claims 25  to  27 , wherein the substrate made of the second settable optical material is obtained either by casting a liquid composition of optical monomers or by injection of an optical thermoplastic material.  
     
     
         29 . Process according to any of  claims 25  to  28 , wherein the hardened layer of the first optical material is a hard coating having abrasion-resistance properties.  
     
     
         30 . Ophthalmic lens comprising an antiglare utility microstructure initially determined by an interferential process imparted into a surface of the lens with a sight-correcting geometry.  
     
     
         31 . Lens according to  claim 30 , wherein the surface comprising the utility microstructure is an abrasion-resistant layer.  
     
     
         32 . Lens according to  claim 30  or  31 , wherein the utility microstructure has antiglare effects.  
     
     
         33 . Lens according to any of  claims 31  to  33 , wherein the surface comprising the utility microstructure has a refraction index equal to or higher than 1.55, preferably equal to or higher than 1.6.