Stereovisioon

Stereovision refers to the ability of an animal to perceive depth and three-dimensional space using two eyes. This visual capability is achieved through binocular vision, where the images received by each eye are slightly different due to the horizontal separation of the eyes. The brain then processes these two disparate images to create a single, unified perception of depth. This difference in perspective is known as binocular disparity.

The degree of binocular disparity is inversely related to the distance of an object. Closer objects produce larger disparities, while more distant objects produce smaller disparities. The brain uses the magnitude of this disparity to calculate the distance to an object. This ability is crucial for many animals, including humans, for tasks such as navigating complex environments, accurately judging distances for hunting or catching prey, and performing fine motor skills.

Animals with forward-facing eyes, such as primates, cats, and birds of prey, typically have a significant overlap in their visual fields and therefore excellent stereovision. This is advantageous for predators that need to precisely locate and capture moving prey. Conversely, animals with eyes on the sides of their heads, like rabbits or horses, have a wider field of view but less binocular overlap, resulting in weaker stereovision. While their overall vision is better for detecting predators from multiple directions, their depth perception is less precise.