A method for creating a 3-D television effect is disclosed in which a scene is recorded with a relative lateral movement between the scene and the recording mechanism. The recording is played back and viewed through a pair of viewer glasses in which one of the lenses is darker and has a spectral transmission...http://www.google.com/patents/US4893898?utm_source=gb-gplus-sharePatent US4893898 - Low differential 3-D viewer glasses and method with spectral transmission properties to control relative intensities
