“The shutting out of surrounding objects, and the concentration of the whole attention . . . produces a dream-like exaltation . . . in which we seem to leave the body behind us and sail into one strange scene after another, like disembodied spirits.”

—Oliver Wendell Holmes, describing the photographic stereo viewer experience in 1861. Quoted by Oliver Sachs in Stereo Sue: Why Two Eyes are Better than One, The New Yorker, June 19, 2006.