A further preferred lens substrate is a (meth)acrylic resin lens substrate which can be formed from a copolymer of a monomer represented by the following formula (3): ##STR3## wherein R5 is a hydrogen atom or a methyl group, R6 is CH2 CH2 or CHCH(OH)CH2, X is a hydrogen atom or a halogen atom other than fluorine, and m and n are each an integer satisfying the condition of 0???m+n???8; and other po