Patent ID: 6673276
Filing Date: 2004-01-06
Classification: B29C,B29D

Abstract:
A process for preparing ophthalmic lenses comprising the steps of:polymerizing a polymerizable composition in the presence of a mould release agent in a casting mould; the mould release agent comprising at least one of: a metal organic compound, a metal organic complex, and a salt thereof, wherein the metal of the mould release agent has an electronegativity of 1.5 to 1.75, when calculated according to the method of Allred and Rochow, and is not Si or P; opening the casting mould to release an ophthalmic lens; and imbibing the ophthalmic lens, after releasing from the casting mold, in a tinting solution to recover a tinted ophthalmic lens substantially free of surface defects including ferns and tinting failures.