Abstract: Polymeric materials suitable for bio-medical applications, particularly in making contact lenses, are derived by reaction of the following:(1) 20 to 40 mole % of a polymerizable amide which is an unsubstituted or substituted amide of a carboxylic acid containing olefinic unsaturation,(2) 25 to 55 mole % of an N-vinyl lactam,(3) 5 to 20 mole % of a polymerizable ester which is an ester of a carboxylic acid containing olefinic unsaturation,(4) 1 to 10 mole % of a polymerizable carboxylic acid containing olefinic unsaturation, and(5) 3 to 10 mole % of a hydrophobic monomer component comprising:(a) a fluorine-containing polymerizable monomer having a fluoroaliphatic side chain, or a polymerizable monomer having an esterifiable group, and(b) a non-fluorine-containing polymerizable hydrophobic vinyl monomer;and subsequently esterifying any esterifiable groups provided by monomer (5a) using a fluorine-containing aliphatic acid or derivative thereof, the amounts of the monomers (1) to (5) totalling 100 mole %, and ei

Abstract: Polymeric materials suitable for biomedical applications, particularly in making contact lenses, are formed by copolymerization and crosslinking of: (1) an amide of an unsaturated carboxylic acid such as acrylamide or methacrylamide; (2) an N-vinyl lactam such as N-vinyl pyrrolidone; (3) an ester of an unsaturated carboxylic acid such as a hydroxy-substituted ester of acrylic or methacrylic acid; (4) an unsaturated carboxylic acid such as acrylic or methacrylic acid; and (5) a hydrophobic monomer component comprising: (a) a fluorine-containing polymerizable monomer having a fluoroaliphatic side chain, such as fluoroalkyl acrylate or methacrylate, and (b) a non-fluorine-containing polymerizable hydrophobic vinyl monomer such as styrene; crosslinking with a crosslinking agent either being carried out during copolymerization or subsequently.

Abstract: Polymeric materials suitable for bio-medical applications, particularly in making contact lenses, are formed by copolymerization and crosslinking of: (1) an amide of an unsaturated carboxylic acid such as acrylamide or methacrylamide; (2) an N-vinyl lactam, such as N-vinyl pyrrolidone; (3) an ester of an unsaturated carboxylic acid, such as a hydroxy-substituted ester of acrylic or methacrylic acid; (4) an unsaturated carboxylic acid, such as acrylic or methacrylic acid; and (5) a polymerizable hydrophobic vinyl monomer, such as styrene; crosslinking with a crosslinking agent either being carried out during copolymerization or subsequently. The resulting polymeric materials may be machined to produce a contact lens form and then hydrated to form a hydrogel which is suitable for use as an extended wear contact lens.

Abstract: In order to measure, for example, the radius of curvature of a soft contact lens, the lens is mounted in a bath of the electrolyte and supported at its periphery on a tubular support. A probe movable along an axis has two electrodes mounted on it and the resistance or impedance between those electrodes and the mount is monitored; when the difference in these resistances or impedances equals a predetermined value, the probe is taken as being a predetermined distance from the lens and the position of the probe relative to the mount is measured by a transducer arrangement. The output from the transducer is converted to digital form and used to address a read-only-memory in which are stored values correlating the position of the probe along the axis with the radius of curvature of the lens.