Abstract: A novel plastic composition material for use in making a corneal contact lens comprising the reaction product of:(a) between about 20 and about 60% by weight of polymerizable silicate having the general formula: ##STR1## wherein R=alkyl, aryl or HR'=R or ORY=alkyl, vinyl, aryl or fluoroalkylZ= ##STR2## A=Y, or H B=oxyalkyl, oxyaryl, oxyfluoroalkyl, oxyalkylacrylate, alkyl esters, aryl esters, fluoroalkylesters, or acrylic esters;(b) from about 0 to about 9% of a polymerizable substituted or unsubstituted lower alkyl ester siloxane, including those having alkyl, aryl, or cycloalkyl substituents forming parts of the siloxane groups;(c) from about 5% to about 50% of a polymerizable substituted or unsubstituted lower alkyl or cycloalkyl acrylic ester;(d) at least 5% of a polymerizable fluoroacrylic ester;(e) a wetting agent material which includes a mixture of acrylic or methacrylic acid and N-(1,1-dimethyl-3-oxybutyl)-acrylamide;(f) at least one catalyst and sufficient crosslinking agents to provide a durable, m

Abstract: A bifocal contact lens blank having a front surface portion which is subdivided into distant and near vision front surface segments. The distant vision segment surface is defined by a partially spherical front surface with a first radius of curvature, and the near vision segment surface is defined by a spherical segment front surface portion with a smaller radius of curvature. The distant vision segment lies in the upper part of the lens blank and the near vision segment in the lower half; the surfaces meet along a locus of tangent points lying generally centrally of the lens and joined to each other on either side of this locus by a pair of offsetting front surfaces which extend between the lowermost edges of the distant vision segment surface and the uppermost edges of the near vision segment surface. These offsetting surfaces lie generally perpendicular to at least one of the segment surfaces, substantially along a meridian of the lens front surface.