Abstract: A contact lens contains a copolymer obtained by copolymerizing, as an indispensable feed monomer, 2 to 95 wt. % of a carboxylic acid ester monomer and 98 to 5 wt. % of a copolymerizable monomer. The carboxylic acid ester monomer is represented by the formula (I) ##STR1## wherein R.sub.1 stands for a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 1 to 12 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms or an aryl group, and X stands for ##STR2## in which R.sub.2 and R.sub.3 each stand for a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 1 to 12 carbon atoms, a cyclic alkyl group having 3 to 12 carbon atoms or an aryl group, m and 1 being integers of from 0 to 4, at least one of R.sub.1, R.sub.2 and R.sub.3 being a group containing a fluorine atom and n being an integer of from 0 to 4.

Abstract: A transparent optical article is constituted of an optical resin. The optical resin in obtained by polymerizing a feed monomer containing at least a diester of unsaturated dicarboxylic acid selected from the group consisting of itaconic acid, citraconic acid and mesaconic acid. The ester group forming the diester is ##STR1## or R, wherein X represents a halogen atom, m represents zero or an integer of 1 to 5 and R represents an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 1 to 12 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms. At least one of the ester groups has an aromatic ring defined above.

Abstract: A contact lens article comprises a resin obtained by copolymerizing starting monomer components containing a silicon-containing compound (A) represented by the formula ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group, X.sub.1 and X.sub.2 each represent a methyl group or ##STR2## l represents 0 or 1, m represents an integer of 1 to 3 and n and p each represent an integer of 0 to 3; a fluorine-containing compound (B) represented by the formula (II) of: ##STR3## wherein at least one of R.sub.2 and R.sub.3 represents a straight chain or branched chain fluoroalkyl group represented by --C.sub.h H.sub.k F.sub.2h+l-k in which h represents an integer of 2 to 18, k represents an integer of 1 to 2 multiplied by h and when one of R.sub.2 and R.sub.3 is --C.sub.h H.sub.k F.sub.2h+l-k, the other of R.sub.2 and R.sub.