Photochromic contact lenses and methods for their production

摘要

The invention provides a photochromic composition for use in tinting contact lenses in which the binding polymer used is capable of forming an interpenetrating polymer network with the lens material. When the photochromic compositions of the invention are applied to uncured lens material that is subsequently cured, the binding polymer forms an interpenetrating polymer network with the lens material embedding the photochromic compound within the lens material resulting in a stable, photochromic lens.