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Abstract

Described are novel photochromic indeno-fused naphthopyran compounds, examples of which include naphthopyran compounds having a substituted or unsubstituted indeno group, the 2,1 positions of which are fused to the naphtho portion of the naphthopyran as shown below. Also present on the naphthopyran are moderate to strong electron donor substituents at the number 6- and 7-positions and optionally at the 8-position of the pyran ring or a cyclic group fused to the h side of the naphtho portion and weak to moderate electron donor substiuents at the 3-position of the pyran ring. Certain substituents may also be present at the number 5, 8, 9, 10, 11, 12, or 13 carbon atoms of the compounds. These compounds have a rating of at least 80 in the Relative .DELTA.OD at Saturation Test and may be represented by the following graphic formula: ##STR1## Also described are polymeric organic host materials that contain or that are coated with such compounds. Optically clear articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., certain other naphthopyrans, benzopyrans, and spiro(indoline)type compounds, are also described.

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