A method for making a silicone hydrogel contact lens is provided. In one embodiment, a prepolymer mixture is polymerized in a lens mold in an atmosphere having less than about 10000 ppm oxygen to form a silicone hydrogel contact lens suitable for extended wear as characterized by producing less than 10% corneal swelling after a period of continuous wear of 7 days including normal sleep periods. In one embodiment, the prepolymer mixture comprises at least one oxyperm material containing hydrophilic groups, wherein the at least one oxyperm material is a siloxane-containing macromer or monomer, at least one ionperm material, and a cross-linking agent. In certain embodiments, the polymerization of the prepolymer mixture may be carried out in an atmosphere having less than about 1000 ppm oxygen.