Photochromic spirooxazine monomers and polysiloxanes

A photochromic compound of the formula:

• ##STR9## wherein R.sup.1 is selected from the group consisting of (A) hydrogen, alkyl, phenyl, benzyl, or an alkyl substituted by halogen, hydroxy, lower alkoxy, carboxyl, lower alkoxycarbonyl, and phenyl and benzyl substituted by cyano or by one or more halogens;
• and (B) (CH.sub.2).sub.n --CH.dbd.CH.sub.2 wherein n is an integer from 1 to 20;
• when R.sup.1 is (B), then R.sup.2 through R.sup.8 are each selected from the group consisting of hydrogen, lower alkyl, and lower alkyl including substitutions from the group consisting of halogen, hydroxy, and lower alkoxy;
• when R.sup.1 is (A) then one of R.sup.2 through R.sup.8 is (C) --X--(CH.sub.2).sub.n --CH.dbd.CH.sub.2, wherein n is an integer from 4 to 20 and X is selected from the group consisting of a covalent bond, O, N--R', (wherein R' is H or lower alkyl), CO--O, CO--NH, and --CH.dbd.N and the remaining ones of R.sup.2 through R.sup.8 are selected from the group consisting of hydrogen, alkyl, and alkyl substituted by halogen, hydroxy and lower alkoxy;
• and R.sup.9 and R.sup.10 form a condensed benzene or pyridine ring.