An optical element including: a substrate; and an at least partial
coating having a first state and a second state on at least a portion of
the substrate, the at least partial coating being adapted to be
circularly polarizing or elliptically polarizing in at least one state
and containing: a chiral nematic or cholesteric liquid crystal material
having molecules that are helically arranged through a thickness of the
at least partial coating; and at least one photochromic-dichroic compound
that is at least partially aligned with the liquid crystal material such
that a long axis of a molecule of the photochromic-dichroic compound is
generally parallel to the molecules of the liquid crystal material.