| abstract |
Described are novel photochromic heterocyclic fused indenonaphthopyran compounds having a substituted or unsubstituted heterocyclic ring fused to the g, h, i, n, o or p side of the indenonaphthopyran. These compounds may be represented by either of the following graphic formulae: ##STR1## Also described are polymeric organic host materials that contain or that are coated with such compounds. |