US Patent 7481955 Photochromic materials comprising metallocenyl groups

Various non-limiting embodiments of the present invention relate to photochromic materials having a metallocenyl group. More particularly, various non-limiting embodiments disclosed herein provide photochromic materials including an indeno-fused naphthopyran, such as an indeno[2′,3′:3,4]naphtho[1,2-b]pyran, and a metallocenyl group bonded to at least one available position on the indeno-fused naphthopyran. Other non-limiting embodiments disclosed herein provide photochromic composition and photochromic articles, such as but not limited to ophthalmic lens, which include the disclosed photochromic materials and method of making the same.