Patent ID: 8287775

Claim:
A photochromic dye, comprising: at least a first photo-reactive group and a second photo-reactive group, wherein the first photo-reactive group is configured to undergo a first photochromic reaction responsive to radiation having a first intensity; the second photo-reactive group is configured to undergo a second photochromic reaction responsive to radiation having a second intensity, wherein the second intensity is different than the first intensity; and wherein the photochromic dye is represented by a structure of Formula I: wherein, X and Y independently represent hydrogen, an electron donor group selected from the group consisting of an amino, an alkylamino, a dialkylamino, an alkyl, an alkoxy, a julolidine or a diphenyl, and combinations thereof or an electron acceptor group selected from the group consisting of a cyano, a nitrogen oxide, a halogen, a trifluoromethyl, a dicyanovinyl or a tricyanovinyl, and combinations thereof, but if X represents an electron donor group then Y represents hydrogen or an electron acceptor group, and if X represents an electron acceptor group then Y represents hydrogen or an electron donor group; and R1 to R16 independently represent hydrogen, a halogen, a substituted or unsubstituted C1-8 alkyl, a substituted or unsubstituted C1-8 alkoxy, a substituted or unsubstituted C1-8 alkenyl, a substituted or unsubstituted C1-8 conjugated alkyl, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or the substituents together form an alkylene or alkenylene chain completing an aryl group.