A photochromic synthetic resin (i.e., plastic) object characterized by a
permanently increased contrast relative to the contrast of prior art
photochromic synthetic resin objects, such that the photochromic synthetic
resin object according to the invention exhibits improved contrast in the
stationary states and in every intervening phase, including both darkening
and lightening. The photochromic synthetic resin objects of the invention
are particularly useful as lenses for eyeglasses, especially for sports
glasses.
