Creation of microstructured spectacle lenses in prescription lens production

Abstract

A method for providing spectacle lenses that have a microstructure on at least one side. A procedure is described, in which the structure is introduced into a face of the lens after the processing of the face of the lens. Processing steps used to achieve the optical quality of the corresponding surface can be omitted. The back face of a spectacle lens may be microstructured by CNC-controlled turning after a first shaping processing, wherein the polishing step is omitted.

1 . A method for producing a lens, comprising:
 providing a lens blank; and   machining at least one lens surface of the lens blank to create a prescription lens surface of the lens, the machining of the at least one lens surface comprising creation of a diffractive microstructure.   
     
     
         2 . The method as claimed in  claim 1 , wherein the lens is a spectacle lens and the prescription lens surface is the back surface of the spectacle lens. 
     
     
         3 . The method as claimed in  claim 1 , wherein the machining of the at least one lens surface for the creation of the prescription surface comprises removal of material with a thickness of at least partially at least about 20 μm. 
     
     
         4 . The method as claimed in  claim 1 , wherein the machining of the at least one lens surface for the creation of a prescription lens surface comprises at least one of milling, turning, and grinding, and the creation of the microstructure takes place after the at least one of milling, turning, and grinding, without any interim polishing of the at least one lens surface. 
     
     
         5 . The method as claimed in  claim 4 , wherein the roughness of the prescription surface before the creation of the microstructure has at least partially an R z  value of one of at least about 5 μm, at least about 10 μm, and at least about 20 μm, and/or an R a  value of one of at least about 0.5 μm, at least about 1 μm, at least about 2 μm, and at least about 5 μm. 
     
     
         6 . The method as claimed in  claim 1 , wherein the creation of the diffractive microstructure comprises machining with material removal that is at least partially greater than the structure size of the diffractive microstructure in the direction of removal. 
     
     
         7 . The method as claimed in  claim 6 , wherein the creation of the microstructure comprises removal of material with a thickness of at least partially at least about 20 μm. 
     
     
         8 . The method as claimed in  claim 1 , wherein the provision of the lens blank comprises molding. 
     
     
         9 . The method as claimed in  claim 1 , wherein the method comprises, prior to the machining of the at least one lens surface, fastening a lens holding block on the lens surface that is facing away from the lens surface that is to be machined, the lens holding block only being removed again after the creation of the diffractive microstructure. 
     
     
         10 . The method as claimed in  claim 1 , wherein the diffractive microstructure is formed in the material of the lens blank. 
     
     
         11 . The method as claimed in  claim 1 , wherein the machining of the at least one lens surface for the creation of the prescription surface comprises removal of material with a thickness of at least partially at least about 20 μm. 
     
     
         12 . The method as claimed in  claim 1 , wherein the machining of the at least one lens surface for the creation of the prescription surface comprises removal of material with a thickness of at least partially at least at least about 0.1 mm. 
     
     
         13 . The method as claimed in  claim 1 , wherein the machining of the at least one lens surface for the creation of the prescription surface comprises removal of material with a thickness of at least partially at least about 0.5 mm. 
     
     
         14 . The method as claimed in  claim 1 , wherein the machining of the at least one lens surface for the creation of the prescription surface comprises removal of material with a thickness of at least partially at least about 2 mm. 
     
     
         15 . The method as claimed in  claim 6 , wherein the creation of the microstructure comprises removal of material with a thickness of at least about 0.1 mm. 
     
     
         16 . The method as claimed in  claim 6 , wherein the creation of the microstructure comprises removal of material with a thickness of at least about 0.5 mm. 
     
     
         17 . The method as claimed in  claim 6 , wherein the creation of the microstructure comprises removal of material with a thickness of at least about 2 mm.