Patent ID: 6557174
Filing Date: 2003-05-06
Classification: A61F,Y10S

Abstract:
An optical filter assembly for protecting eyes in an environment having a switchable intense light source comprising:A. a base with an aperture therethrough, a cavity spaced from the aperture and a channel interconnecting said cavity and said channel, said base being formed of a material having a fixed light transmission characteristic, B. a filter disposed in the aperture switchable between a first optical density corresponding to the fixed light transmission characteristic of said base and a second, reduced optical density, C. a control circuit mounted in said cavity and connected to said filter through said channel for controlling the optical density of said filter in response to the presence of the intense light, and D. an opaque filler in said cavity and said channel whereby substantially uniform vision is provided through said filter and said base in the presence of the intense light and whereby vision is limited to said filter in the absence of the intense light.