The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 17, 1989
Filed:
Jun. 11, 1985
Otto Wichterle, Prague, CS;
Ceskoslovenska akademie ved, , CS;
Abstract
A toric contact lens with the center of gravity displaced in the direction to its edge by the effect of an one-sided thickening of the lens, where, according to the invention, its optical zone has as far as to the diameter of 5 to 8 mm the center of gravity precisely in the lens axis and the thickening is performed at one place of its edge to displace the center of gravity of the whole lens outside its axis, which thickening has the form of a drop, which would be formed by running down a liquid wetting a front convex surface of the lens if the lens is placed in the vertical position, whereas the direction of displacement of the center of gravity includes the required angle with the direction of toricity of the optical zone. The casting surface of mould for production of the toric contct lens according to the invention is provided with a marginal cavity corresponding to the required thickening. Moulds charged with a metered amount of monomer mixture are used for casting of the lens according to the invention in common equipment either for spin casting or for static casting in closed moulds.