Seeing with two eyes; also called binocular vision. Stereoscopic vision increases the ability to sense depth. Two-dimensional images don't take advantage of this capability, unless they present a different image on which each eye can fix. Several means have been devised to do this. Stereo photographs , sometimes called stereograms or stereographs have been produced since the mid-1800s. Popular since the early 1990s are computer-generated stereograms with images hidden inside of them. Other resources: Stereoviews.com is a great source. Also see binocular vision and photography.