Editing Depth perception (section)

{{Short description|Visual ability to perceive the world in 3D}}
{{For|objective comparisons of size|Orders of magnitude (length)}}
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[[File:Depth cues 1.png|thumb|440px|right|Perspective, relative size, occultation and texture gradients all contribute to the three-dimensional appearance of this photo.]]
'''Depth perception''' is the ability to perceive distance to objects in the world using the [[visual system]] and [[visual perception]]. It is a major factor in perceiving the world in [[three-dimensional space|three dimensions]].

'''Depth sensation''' is the corresponding term for non-human animals, since although it is known that they can sense the distance of an object, it is not known whether they [[perception|perceive]] it in the same way that humans do.<ref>{{cite book|last=Howard|first=Ian|title=Perceiving in Depth|year=2012|publisher=Oxford University Press|location=New York|isbn=978-0-199-76414-3}}</ref>

Depth perception arises from a variety of depth cues. These are typically classified into [[Binocular vision|binocular]] cues and [[monocular vision|monocular]] cues. Binocular cues are based on the receipt of sensory information in three dimensions from both eyes and monocular cues can be observed with just one eye.<ref>Sternberg, R. K. (2012).</ref><ref>Goldstein E.B. (2014, 2017) ''[https://books.google.com/books?id=x5d4CgAAQBAJ&q=%22Depth+perception%22 Sensation and perception]'' (10th ed.). Pacific Grove, Calif.: Wadsworth.</ref> Binocular cues include retinal [[Binocular disparity|disparity]], which exploits [[parallax]] and [[vergence]]. [[Stereopsis]] is made possible with [[binocular vision]]. Monocular cues include relative size (distant objects subtend smaller [[visual angle]]s than near objects), texture gradient, occlusion, linear perspective, contrast differences, and motion [[parallax]].<ref>{{cite journal |author=Burton HE |year=1945 |title=The optics of Euclid |journal=Journal of the Optical Society of America |volume=35 |pages=357–372 |doi=10.1364/JOSA.35.000357 |issue=5|bibcode=1945JOSA...35..357B }}</ref>