METHODS FOR PREPARING COMPOSITE PHOTOCHROMIC OPHTHALMIC LENSES AND A PHOTOCHROMIC LENS amp; xA;

摘要

A method of manufacturing a composite photochromic ophthalmic lens having an index of refraction of at least 1.49 involves providing against a front portion (6) of a mold a first composition (8) including a polymerizable monomer, oligomer or polymer and a photochromic compound and filling a rear portion (10) of the mold with a second composition, sufficiently different from the first such that a distinct phase boundary results between the two compositions when fully cured. Either the first or second composition can be gelled before adding the other composition, in an ungelled state, to the mold. The compositions are cured simultaneously while in intimate contact.