Because of this, each eye receives a slightly different view of the world. When the two images are fused into one overall image, stereoscopic vision occurs. This produces a powerful sensation of depth. And, retinal disparity can be used to produce 3-D movies by filming with two cameras separated by several inches. Later, both images are simultaneously projected on a screen.
Audience members wear glasses that filter out one of the images to each eye.
Since each eye gets a separate image, normal stereoscopic vision is duplicated. Notice that two squares of random dots contain no lines, edges, or distinct patterns. Researcher Bela Julesz believes the designs show that the brain is very sensitive to any mismatch of information from the eyes. To a large extent, three-dimensional space is woven from countless tiny differences between what the right and left eyes see. A one-eyed person lacks convergence and retinal disparity, and accommodation is helpful mainly for judging short distances.