| abstract |
Described are novel reversible photochromic naphthopyran compounds having at least one ortho substituted phenyl group at the 3-position of the pyran ring. 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 compound or combinations thereof with complementary photochromic compounds, e.g., spiro(indolino)-oxazine type compounds, are also described. |