05608489 is referenced by 9 patents and cites 5 patents.

An anamorphic lens system in an eye direction detection device, applied to an observing optical system, modifies illumination light from a light source to be parallel in a lateral direction of a user's eye positioned to look through the observing optical system, dispersed in a vertical direction of the position of the user's eye, and substantially centered on the position of the user's eye. The anamorphic lens system transmits the illumination light from the light source to an illumination light exit surface positioned away from the optical axis of the observing optical system, and the illumination light is projected toward the position of the user's eye from the illumination light exit surface to separate signals from the image of the eye and an image formed by eyeglasses, if worn. The illumination light exit surface is a rectangular window having a longitudinal side parallel to longitudinal side of a field of view of the observing optical system, and is positioned below the position of a user's eye.

Eye direction detecting device
Application Number
Publication Number
Application Date
May 24, 1996
Publication Date
March 4, 1997
Hiroyasu Ozaki
Greenblum & Bernstein
Asahi Kogaku Kogyo Kabushiki Kaisha
A61B 3/10
G03B 13/02
View Original Source