To ensure high oxygen permeability and high mechanical strength by using a polymer obtd. by polymerizing a polymerizable compsn. contg. a specified maleimide deriv., styrene and/or α-methylstyrene, N,N- dimethylacrylamide and/ or N,N-vinylpyrrolidone and a specified monomer.

The highly hydrous contact lens is made of a polymer obtd. by polymerizing a polymerizable compsn. contg. 2-20 pts.wt. maleimide deriv., 2-20 pts.wt. styrene and/or α-methylstyrene, 60-80 pts.wt. N,N-dimethylacrylamide and/or N,N-vinylpyrrolidone and 5-30 pts.wt. at least one monomer selected from among alkyl (meth)acrylates, alkyl itaconates, aliphatic carboxylic acid vinyl esters, etc., represented by the formula. In the formula, R2 and R2 are each H or 1-2C alkyl and R3 is H, l-12C alkyl or the like.