The Neural Control of Vision
L. The Processing of Depth

Another method that has been developed for producing an impression of depth using random-dot displays is the autostereogram that has the advantage of not needing a stereoscope. An example of such a display appears in Figure 54. By staring beyond the random dots until three dots are seen instead of the two that are physically present above the display, a portion of the image will be seen to protrude in depth. Viewing these kinds of displays can be a lot of fun. One source of this is the Magic Eye books (N.E. Thing Enterprises, Magic eye : a new way of looking at the world : 3D illusions (1993) Kansas City, MO: Andrews and McMeel).