Binocular Vision

Binocular vision is vision in which both eyes are used together. The word binocular comes from two Latin roots, bini for double, and oculus for eye. Having two eyes confers at least four advantages over having one. First, it gives a creature a spare eye in case one is damaged. Second, it gives a wider field of view. For example, humans have a maximum horizontal field of view of approximately 200 degrees with two eyes, approximately 120 degrees of which makes up the binocular field of view (seen by both eyes) flanked by two uniocular fields (seen by only one eye) of approximately 40 degrees. Third, it gives binocular summation in which the ability to detect faint objects is enhanced. Fourth, it can give stereopsis in which binocular disparity (or parallax) provided by the two eyes' different positions on the head give precise depth perception. Such binocular vision is usually accompanied by singleness of vision or binocular fusion, in which a single image is seen despite each eye having its own image of any object. Other phenomena of binocular vision include utrocular discrimination, eye dominance, allelotropia, and binocular rivalry. Stereopsis (from stereo- meaning "solid" or "three-dimensional", and opsis meaning appearance or sight) is the impression of depth that is perceived when a scene is viewed with both eyes by someone with normal binocular vision. Binocular viewing of a scene creates two slightly different images of the scene in the two eyes due to the eyes' different positions on the head. These differences, referred to as binocular disparity, provide information that the brain can use to calculate depth in the visual scene, providing a major means of depth perception. The term stereopsis is often used as short hand for 'binocular vision', 'binocular depth perception' or 'stereoscopic depth perception', though strictly speaking, the impression of depth associated with stereopsis can also be obtained under other conditions, such as when an observer views a scene with only one eye while moving. Observer motion creates differences in the single retinal image over time similar to binocular disparity; this is referred to as motion parallax. Importantly, stereopsis is not usually present when viewing a scene with one eye, when viewing a picture of a scene with both eyes, or when someone with abnormal binocular vision (strabismus) views a scene with both eyes. This is despite the fact that in all these three cases humans can still perceive depth relations.

Orthoptists are eyecare professionals who fix binocular vision problems.

Read more about Binocular Vision:  Field of View and Eye Movements, Binocular Summation, Binocular Interaction, Utrocular Discrimination, Singleness of Vision, Eye Dominance, Stereopsis, Allelotropia, Binocular Rivalry, Disorders

Other articles related to "vision, binocular vision, binocular":

Equine Vision - Visual Capacity of The Horse - Visual Field
... are set on the sides of its head, allowing it close to a 350° range of monocular vision ... This means horses have a range of vision of more than 350°, with approximately 65° of this being binocular vision and the remaining 285° monocular ... The horse's wide range of monocular vision has two "blind spots," or areas where the animal cannot see in front of the face (making a cone that comes to a point ...
Binocular Vision - Disorders
... To maintain stereopsis and singleness of vision, the eyes need to be pointed accurately ... person with some phoria will notice a brief episode of double vision or diplopia after uncovering the eye ... can also be used for more problematic disorders of binocular vision, the tropias ...
Tyrannosaurus - Biology - Feeding Strategies
... eyes would point forward, giving them binocular vision slightly better than that of modern hawks ... Horner also pointed out that the tyrannosaur lineage had a history of steadily improving binocular vision ... which would not have needed the advanced depth perception that stereoscopic vision provides ...
Depth Perception - Evolution
... Most open-plains herbivores, especially hoofed grazers, lack binocular vision because they have their eyes on the sides of the head, providing a panoramic, almost 360°, view of the horizon - enabling them to ... have both eyes looking forwards, allowing binocular depth perception and helping them to judge distances when they pounce or swoop down onto their prey ... Animals that spend a lot of time in trees take advantage of binocular vision in order to accurately judge distances when rapidly moving from branch to branch ...
Stereopsis
... of depth that is perceived when a scene is viewed with both eyes by someone with normal binocular vision ... Binocular viewing of a scene creates two slightly different images of the scene in the two eyes due to the eyes' different positions on the head ... These differences, referred to as binocular disparity, provide information that the brain can use to calculate depth in the visual scene, providing a major means of depth perception ...

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