Lens blanks for ophthalmic elements

Abstract

A polymeric front optical element blank is provided which may be laminated to a rear optical element blank. The polymeric front blank comprises an optical element having an exterior convex surface and an interior concave surface, with an edge between the exterior convex surface and the interior concave surface. The optical is provided with at least two projections which extend away from and higher than the edge on a side of the optical element having the concave surface. These projections assist in aligning an back optical element during lamination so that the two lenses will not move out of optical registry during lamination, especially where centrifugal forces are used to spread an adhesive between the front and rear lenses. It is preferred that there are at least three projections extending away from and higher than the edge on a side of the optical element having the concave surface. A particularly desirable and preferred process for using these lenses comprises the steps of: a) positioning a first optical element blank according to the invention having an interior surface and an exterior surface, b) applying a photopolymerizable adhesive composition on the interior surface of the optical element blank, the photopolymerizable adhesive composition being curable by UV radiation having a wavelength of between 385 and 410 nm, and the maximum spectral sensitivity of the photopolymerizable composition being within 15 nm of said UV radiation having a wavelength of between 385 and 410 c) positioning a second optical element blank having an interior surface and an exterior surface on the polymerizable adhesive composition with an interior face in contact with the polymerizable adhesive composition to form a prelaminated association, wherein at least one of the first and second optical element blanks absorbing at least 95% of any ultraviolet radiation component between 180 and 380 nm of incident radiation and allows at least 30% transmittal of at least one wavelength of ultraviolet radiation between 385 and 410 nm, and d) irradiating the prelaminated association with UV radiation having a significant component between 385 and 410 nm through at least one of the first and second optical element blanks to cure the adhesive and to laminate the first and second optical elements.

What is claimed:  
     
         1 . A pair of ophthalmic lens blanks comprising a front lens blank and a rear lens blank nested against each other with a liquid, photocurable adhesive between said front lens blank and said rear lens blank, at least one of said front lens blank and said rear lens blank having topography above a surface of at least one of said lens blanks which prevents the other of said lens blanks from slipping out of nesting contact with said at least one of said lens blanks.  
     
     
         2 . The pair of ophthalmic lens blanks of    claim 1    in which said topography is selected from the group consisting of: 
 a) roughness of a portion of a surface of one of said lens blanks, which portion of a surface is outside of a significant optical area of one of said lens blanks, and which roughness increases the static coefficient of friction between said two lens blanks;  
 b) at least two protrusions extending from a concave surface of one of said lenses, the other of said lenses nesting within said concave surface, said at least two protrusions extending high enough from said concave surface to make contact with an edge of said other lens nesting within said concave surface; and  
 c) protrusions extending away from a convex side of one of said lens blanks and over an edge of a lens blank nested against said convex side of one of said lens blanks.  
 
     
     
         3 . A method for forming a laminated optical element comprising the steps of: 
 a) positioning a pair of ophthalmic lens blanks into nesting contact according to    claim 1   , with said front lens having an interior surface and an exterior surface,    b) applying a photopolymerizable adhesive composition on said interior surface of said front lens blank, said photopolymerizable adhesive composition being curable by UV radiation having a wavelength of between 385 and 410 nm, and the maximum spectral sensitivity of said photopolymerizable composition being within 15 nm of said UV radiation having a wavelength of between 385 and 410 nm,    c) positioning a second ophthalmic lens blank having an interior surface and an exterior surface on said polymerizable adhesive composition with an interior face in contact with said polymerizable adhesive composition to form a prelaminated association, wherein at least one of said first and second ophthalmic lens blanks absorbing at least 95% of any ultraviolet radiation component between 180 and 380 nm of incident radiation and allows at least 30% transmittal of at least one wavelength of ultraviolet radiation between 385 and 410 nm, and    d) irradiating said prelaminated association with UV radiation having a significant component between 385 and 410 nm through said at least one of said front and rear ophthalmic lens blanks to cure said adhesive and to laminate said first and second ophthalmic lens blanks.    
     
     
         4 . The method of    claim 3    wherein said first and second ophthalmic lens blanks are laminated to form a segmented or continuous lens.  
     
     
         5 . The method of    claim 4    wherein said adhesive comprises a (m)ethacrylic polymerizable composition.  
     
     
         6 . The method of    claim 3    wherein at least one of said first and second ophthalmic lens blanks has a UV absorbing coating on at least one surface thereof.  
     
     
         7 . The method of    claim 4    wherein at least one of said first and second ophthalmic lens blanks has a UV absorbing coating on at least one surface thereof.  
     
     
         8 . The method of    claim 5    wherein at least one of said first and second ophthalmic lens blanks has a UV absorbing coating on at least one surface thereof.  
     
     
         9 . The method of    claim 4    wherein said adhesive is spread in a continuous film between said first and second ophthalmic lens blanks before photopolymerization of the adhesive.  
     
     
         10 . The method of    claim 7    wherein said adhesive is spread in a continuous film between said first and second ophthalmic lens blanks before photopolymerization of the adhesive.  
     
     
         11 . The method of    claim 8    wherein said adhesive is spread in a continuous film between said first and second ophthalmic lens blanks before photopolymerization of the adhesive.  
     
     
         12 . The method of    claim 9    wherein said spreading is performed by spinning said prelaminated association before photopolymerization of said adhesive.  
     
     
         13 . The method of    claim 10    wherein said spreading is performed by spinning said prelaminated association before photopolymerization of said adhesive.  
     
     
         14 . The method of    claim 11    wherein said spreading is performed by spinning said prelaminated association before photopolymerization of said adhesive.  
     
     
         15 . A method for laminating two optical element blanks comprising the steps of: 
 a) positioning a first optical element blank according to    claim 2    having an interior surface and an exterior surface,    b) applying a photopolymerizable adhesive composition on the interior surface of the first ophthalmic lens blank,    c) positioning a second ophthalmic lens blank having an interior surface and an exterior surface on the polymerizable adhesive composition with an interior face in contact with the polymerizable adhesive composition to form a first prelaminated association,    d) relatively moving said second ophthalmic lens blank away from said first ophthalmic lens blank, breaking contact between said first ophthalmic lens blank and said second ophthalmic lens blank, with a surface of said second ophthalmic lens blank having been wet by said adhesive,    e) placing said wet surface of said second ophthalmic lens blank into contact with the adhesive on the interior surface of said first ophthalmic lens blank to form a second prelaminated association,    f) spreading said adhesive between said first and second ophthalmic lens blanks, and    g) curing the adhesive and to laminate said first and second ophthalmic lens blanks.    
     
     
         16 . The method of    claim 15    wherein said adhesive is a photocurable adhesive.  
     
     
         17 . The method of    claim 16    wherein said first and second ophthalmic lens comprise ophthalmic elements and the two optical elements are laminated to form a segmented or continuous lens blank.  
     
     
         18 . The method of    claim 17    wherein said adhesive comprises a (m)ethacrylic polymerizable composition.  
     
     
         19 . The method of    claim 17    wherein at least one of said first and second ophthalmic lens has a UV absorbing coating on at least one surface thereof.  
     
     
         20 . The method of    claim 16    wherein at least one of said first and second ophthalmic lens has a UV absorbing coating on at least one surface thereof.  
     
     
         21 . The method of    claim 15    wherein said spreading of adhesive is effected by rotating said second prelaminated association to cause said adhesive to spread between said first and second ophthalmic lens blanks.  
     
     
         22 . A polymeric front optical element blank comprising an optical element having an exterior convex surface, an interior concave surface, and an edge, said optical element having at least two projections extending away from and higher than a portion of said interior concave surface.  
     
     
         23 . The polymeric front optical element blank of    claim 22    wherein there at least three projections extending away from said interior concave surface of the optical element blank.  
     
     
         24 . The polymeric front optical element of    claim 23    comprising an ophthalmic lens blank.  
     
     
         25 . The polymeric front optical element blank of    claim 24    wherein said blank comprises a polycarbonate resin.  
     
     
         26 . The polymeric front optical element blank of    claim 24    wherein said blank comprises a molded blank consisting essentially of polycarbonate resin.  
     
     
         27 . The polymeric front optical element blank of    claim 24    wherein there is at least one protrusion on a convex surface which does not contribute to prescription ophthalmic properties in said ophthalmic lens blank.  
     
     
         28 . The polymeric front optical element blank of    claim 24    wherein there is at least one recess which does not contribute to prescription ophthalmic properties in said ophthalmic lens blank on a side of the front optical element blank having a convex surface.  
     
     
         29 . The polymeric front optical element blank of    claim 24    wherein said blank has a UV absorbing coating on a convex surface thereof.  
     
     
         30 . The polymeric front optical element of    claim 24    wherein said projections are at least 1 mm in height.  
     
     
         31 . The polymeric front optical element of    claim 24    wherein said projections are at least 2 mm in height over said edge.  
     
     
         32 . A set of at least ten different polymeric front optical elements according to    claim 1    wherein each of said at least ten optical elements differs in diopter by at least 0.1 diopters difference between each optical element.  
     
     
         33 . A set of at least ten different polymeric front optical elements according to    claim 24    wherein each of said at least ten optical elements differs in diopter by at least 0.2 diopters difference between each optical element.  
     
     
         34 . A set of at least ten different polymeric front optical elements according to    claim 1    wherein each of said at least ten optical elements differs in diopter by at least 0.25 diopters difference between each optical element.  
     
     
         35 . A set of at least ten different polymeric front optical elements according to    claim 1    wherein each of said at least ten optical elements differs in diopter by at least 0.25 diopters difference between each optical element, and each optical element has a removable label thereon which identifies optical properties of the optical element.  
     
     
         36 . A set of at least ten different polymeric front optical elements according to    claim 24    wherein each of said at least ten optical elements differs in diopter by at least 0.1 diopters difference between each optical element.  
     
     
         37 . A set of at least ten different polymeric front optical elements according to    claim 24    wherein each of said at least ten optical elements differs in diopter by at least 0.2 diopters difference between each optical element.  
     
     
         38 . A pair of polymeric optical elements comprising a front optical element blank and a rear optical element blank to be laminated comprising 
 a) a polymeric front optical element blank comprising an optical element having an exterior convex surface and an interior concave surface, with an edge extending between said exterior convex surface and an interior concave surface, said polymeric front optical element having at least two projections extending away from and higher than the concave surface of the polymeric front optical element blank, said at least two projections having a linear distance between them, and    b) a polymeric rear optical element blank, the diameter of said polymeric rear optical element blank being less than said liner distance, but no more than 2.5 mm less than said linear distance,    a convex surface of said second polymeric rear optical element blank being capable of lying contiguous with a concave surface of said polymeric front optical element blank.    
     
     
         39 . The pair of optical elements of    claim 38    wherein the diameter of said second polymeric rear optical element is less than said linear distance, but is no more than 2.0 mm less than said linear distance.  
     
     
         40 . The pair of optical elements of    claim 38    wherein each of said optical elements is an ophthalmic lens.  
     
     
         41 . The pair of optical elements of    claim 40    wherein each of said optical elements is an ophthalmic lens.  
     
     
         42 . A polymeric front optical element blank comprising an optical element having an exterior convex surface and an interior concave surface, with an edge extending between said exterior convex surface and said interior concave surface, said optical element having at least two projections, formed from the same polymer as the optical element, extending away from and higher than the concave surface.  
     
     
         43 . The optical element blank of    claim 42    wherein said at least two projections comprise at least three projections integrally formed with said optical element.  
     
     
         44 . The optical element blank of    claim 43    wherein said optical element comprises an ophthalmic lens.  
     
     
         45 . The optical element blank of    claim 44    wherein said lens and said at least three projections comprise a polycarbonate.