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.

Abstract: A bifocal contact lens having a principal, distant vision body portion made from a material having a first index of refraction, and a bifocal segment fused in place at least partially within the body and formed from a material having a second index of refraction higher than the first index. The lens has an arcuate lower bifocal segment surface lying generally parallel to the outer edge of the lens body and terminating at a pair of outer end portions which are spaced from each other by a first included angle. The upper bifocal segment surface has at least three elements including a first, radially inner partially circular surface element disposed generally inwardly of the lens, and terminating at a pair of inner end portions spaced from each other by a second included angle. The second and third upper bifocal segment surface elements extend respectively between the outer and inner end portions, with the included angles being less than 170.degree.

Abstract: A method of forming a fused bifocal contact lens having "no jump" characteristics at all points of the segment line separating the distant vision segment or zone from the near vision zone is disclosed. In one embodiment a cylindrical blank is rotated about a given center line and a front curve imparted thereto by moving a tool in an arc about a point radially offset from said center line, in which an opening is then cut in the center of the resulting blank of a size desired to provide a distant vision segment, in which a mass of fluid material for forming the remainder of the lens is cast in place covering at least a portion of said blank, including the front surface portion and the opening therein to form a composite blank, and in which the resulting composite blank is cut to form a contact lens such that the rear base curve thereof comprises portions of both near and far vision segments in which the front surface comprises entirely material from which the far vision portion is made.