Stereo images enhance diagnostic information by providing a visual sense of depth and realism beyond ordinary two-dimensional photographs and are particularly useful in identifying the anatomic location of pathologic findings. . The use of this technique in ophthalmology dates back as far as 1909, but it wasn’t until the 1960’s that stereo fundus photography became widely employed after Lee Allen described a practical technique for sequential stereo fundus photography. This technique is an example of how we can take advantage of the optical interaction between the subject eye and camera. Laterally shifting the fundus camera a few millimeters between sequential photographs causes the illuminating beam of the fundus camera to fall on opposite slopes of the cornea. The resulting cornea-induced parallax creates a hyper-stereoscopic effect that is evident when the sequential pair of photographs is viewed together. Stereo imaging is a standard protocol for many clinical trials investigating treatment of retinal diseases. Stereo imaging techniques have also been employed for slit-lamp biomicrography and to a lesser extent, external photography.
See more in this section on stereo imaging and techniques:
To view any of the anaglyph stereo images on these pages, use red/cyan anaglyph glasses with the red lens covering your left eye.
Previous versions of these blogs were posted on the OPS Stereo Geeks Group page. This site contains several blog posts and PDF articles on stereo techniques in ophthalmology, as well as a recent blog on a 2014 stereo exhibit in Toronto.