Editing Depth perception (section)

=== Stereopsis, or retinal (binocular) disparity, or binocular parallax ===
{{main|Stereopsis}}
[[Animal]]s that have their eyes placed frontally can also use information derived from the different projections of objects onto each [[retina]] to judge depth. By using two images of the same scene obtained from slightly different angles, it is possible to [[triangulation|triangulate]] the distance to an object with a high degree of accuracy. Each eye views a slightly different angle of an object seen by the left and right eyes. This happens because of the horizontal separation parallax of the eyes. If an object is far away, the disparity of that image falling on both retinas will be small. If the object is close or near, the disparity will be large. It is stereopsis that tricks people into thinking they perceive depth when viewing [[Magic Eye]]s, [[autostereogram]]s, [[3-D film|3-D movies]], and [[Stereoscopy|stereoscopic photos]].