Patent 7557206 was granted and assigned to Transitions Optical on July, 2009 by the United States Patent and Trademark Office.
Various non-limiting embodiments disclosed herein relate generally to photochromic compounds, which may be thermally reversible or non-thermally reversible, and articles made therefrom. Other non-limiting embodiments relate to photochromic-dichroic compounds, which may be thermally reversible or non-thermally reversible, and articles made therefrom. For example, one non-limiting embodiment provides a thermally reversible, photochromic compound adapted to have at least a first state and a second state, wherein the thermally reversible, photochromic compound has an average absorption ratio greater than 2.3 in at least one state as determined according to CELL METHOD. Another non-limiting embodiment provides a photochromic compound comprising: (a) at least one photochromic group chosen from a pyran, an oxazine, and a fulgide; and (b) at least one lengthening agent L attached to the at least one photochromic group and represented by the formula —[S1]c-[Q1-[S2]d]d′-[Q2-[S3]e]e′-[Q3-[S4]f]f′—S5—P, which is described herein.