Once the material of playful gatherings, stereoscopic
photographs of cities, the moon, landscapes and
fashion scenes are now cherished collectors’ items
that keep on inspiring new generations of enthusiasts.
Nevertheless, for a stereoblind observer, a stereoscopic
photograph will merely be two similar images placed
side by side. The perspective created by stereoscopic
fusion can only be experienced by those who have
binocular vision, or stereopsis. There are several causes
of a lack of stereopsis. They include eye disorders
such as strabismus with double vision. Interestingly,
stereoscopy can be used as a therapy for that condition.
This paper approaches this kind of therapy through the exploration of North American collections of stereoscopic charts that were used for diagnosis
and training purposes until recently.
