PURPOSE: To obtain a contact lens material having a preferred hardness and oxygen permeability by subjecting a contact lens organic material and a carboxylic acid ester having no β-hydrogen to free radical polymerization.

CONSTITUTION: (A) a contact lens organic material selected from a specific ethylenically unsaturated organosilicone, a fluoro-silicone acrylate, a fluoroacrylate, a HEMA polymer, etc., and (B) a carboxylic acid ester derived from an alcohol having no β-hydrogen and represented by the formula (A is mesaconic acid, itaconic acid, citraconic acid, methylene malonate, etc.; n is 1-3; R1-R3 are each 1-10C alkyl, cycloalkyl, aryl, 2-10C ether) are subjected to free radical polymerization to obtain an oxygen permeable contact lens material having a Shore D hardness of 70 or more and a DK value of 10 or more.