a material that can be applied as implants designed to artificially replace or augment the cornea , such as an artificial cornea , corneal onlay , or corneal inlay is provided . the artificial corneal implant has a double network hydrogel with a first network interpenetrated with a second network . the first network and the second network are based on biocompatible polymers . at least one of the network polymers is based on a hydrophilic polymer . the artificial cornea or implant has epithelialization promoting biomolecules that are covalently linked to the surface of the double network hydrogel using an azide - active - ester chemical linker . corneal epithelial cells or cornea - derived cells are adhered to the biomolecules . the double network has a physiologic diffusion coefficient to allow passage of nutrients to the adhered cells .