A device (100, 140, 150) for differentially absorbing light, depending on
the state of linear polarization of the light, is disclosed. This
polarizing effect is induced and controllable by the level of ambient
light impinging on the device. The device (100, 140) may be used as an
anti-glare vision protection device which selectively absorbs specularly
reflected sunlight in brightly lit environments while permitting all light
to pass in dimly lit environments. The device (100) includes a carrying
medium which may be a film (142) or opposed substrates (112) that are
sealed. A film or the opposed substrates carry a mixture (120) of fluid
material (124) and photochromic dyestuffs (122), wherein the photochromic
material is activated upon the detection of ultraviolet light so as to
absorb some of the light and wherein the energization of the photochromic
material effects the material so as to simultaneously selectively absorb
the specularly reflected sunlight. The material (124) may be any fluid
that dissolves the photochromic dyestuff material (122). The fluid is
preferably a liquid crystal material such as nematic or chiral nematic.
Alternatively, the material (124) may be a polymer liquid crystal. The
device (150) may allow for electrical control of the absorptive
properties.
