PURPOSE: To provide a material passing a larger amt. of oxygen than polymethyl methacrylate while maintaining the useful characteristics of the polymethyl methacrylate.

CONSTITUTION: When 60-95 pts.wt. methyl methacrylate is radical-copolymerized with 5-40 pts.wt. acrylic (methacrylic) ester represented by the formula [where X is H or CH3 and (n) is an integer of 1-10], they are mixed with 20-120 pts.wt. mixture of an org. solvent incompatible with methyl methacrylate with an org. solvent compatible with methyl methacrylate and the resulting mixture is radical-polymerized to obtain a polymethyl methacrylate copolymer. This copolymer is ground and polished to obtain the objective microporous hard contact lens passing a large amt. of oxygen.