for hardness and for diluting the viscosity in various embodiments of the present invention the polymer filler comprises an epoxy functionality vinyl ether functionality silane functionality or acrylate functionality polyfunctional monomers such as trimethylolpropane tri meth acrylate hexanediol meth acrylate tripropylene glycol di meth acrylate diethylene glycol di meth acrylate pentaerythritol tri meth acrylate dipentaerythritol hexa meth acrylate 1 6 hexanediol di meth acrylate or neopentyl glycol di meth acrylate or mixtures and combinations of any of the foregoing are common and useful other hardcoats as are known in the art can be used as polymeric fillers of the present invention in various embodiments a polymeric filler of the present invention comprises a member selected from the group consisting of epoxies vinyl ethers vinyl esters and mixtures thereof which are cured by ultraviolet light activating photoinitiators yielding cationic chemical curing agents polymer filler compositions of the present invention as defined herein include organically modified and unmodified sol gel and the polymer fillers described herein can also further include the addition of various inorganic particles which can further improve the hardness of the polymer filler layer and hence the hardness of the combined polymer filler layer and the porous inorganic layer.