SELECTIVELY WETTABLE AND OXYGEN-PERMEABLE LENSES
A contact lens includes a body, having the plurality of monomers including at least some silicone monomer units including at least one zwitterionic distributed throughout the body. The contact lens includes a front surface and a back surface, where the silicone monomer including at least one zwitterionic group can be present in a greater concentration nearest the front surface than the back surface or a point therebetween. The contact lens can be formed by casting a polymer mixture containing the silicone monomer including at least one zwitterionic group.