Photochromic naphthopyrans

摘要

Described are novel reversible photochromic naphthopyran compounds substituted at the number eight carbon atom on the naphtho portion of the naphthopyran ring with, for example, a methoxy group. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds are also described.