Within the science of vision, binocular vision focuses on the question of how humans and animals perceive the world with two eyes instead of one. Two main areas are distinguished: directional vision and depth perception (stereopsis). In addition, both eyes can positively or negatively influence each other's vision through binocular interaction.

In medical science, binocular vision refers to binocular vision disorders and tests and exercises to improve binocular vision. In biology, binocular vision refers to the fact that the placement of the eyes affects the capabilities of depth perception and directional vision in animals. In society, binocular vision refers to applications for seeing stereoscopic images and aids for binocular vision.

Directional vision focuses on the question of how the images from the two eyes are combined in perception into a combined image and how the directions in which each eye sees the objects around us are converted into practically useful information.

The main article on directional vision describes that the direction in which the left and right eyes see an object can be combined in three different ways. This leads to seeing a single image, double images or a fused image. This perception is linked to a certain quality of depth perception: fine stereopsis or coarse stereopsis.

Depth perception focuses on the question of how the brain uses the difference in perspective between the two eyes to recognise shapes and objects, to see through camouflage, and to gather information about spatial relationships.

The main article on stereopsis discusses the qualities of depth perception, the area of space they cover, and how the observer controls the input through attention and eye movements.

Binocular interaction occurs when there is an interaction between the two eyes, which causes vision with both eyes to be different than with one eye alone. Vision can be better (binocular summation) or worse (binocular inhibition).

In binocular summation, the signals from both eyes reinforce each other so that visual acuity, contrast sensitivity, flicker sensitivity, and brightness sensitivity improve. Maximum binocular summation occurs when the sensitivities of each eye are equal. Differences in sensitivity decrease the effect of binocular summation. The effect of binocular summation decreases with age.