US Patent 7978391 Polarizing, photochromic devices and methods of making the same

A liquid crystal cell including a first substrate having a first surface; a second substrate having a second surface, wherein the second surface of the second substrate is opposite and spaced apart from the first surface of the first substrate so as to define a region; and within the region defined by the first surface and the second surface, a liquid crystal material adapted to be at least partially ordered and at least one thermally reversible photochromic-dichroic compound adapted to be at least partially aligned and having an average absorption ratio greater than 2.3 in an activated state.