Syvyysnäky

Syvyysnäky, also known as stereopsis or binocular vision, is the ability to perceive depth and three-dimensional space. This is achieved by the brain processing the slightly different images received from each eye. Because our eyes are separated horizontally, each eye captures a unique perspective of the world. This difference in perspective, known as retinal disparity, is the fundamental cue for stereoscopic vision.

The brain's visual cortex analyzes these disparities and fuses the two images into a single, coherent perception of depth. The degree of disparity between the two images correlates with the distance of an object. Objects that are closer will have a larger disparity, while objects further away will have a smaller disparity. This ability is crucial for tasks requiring fine motor control and spatial judgment, such as catching a ball, navigating complex environments, or performing surgery.

While stereoscopic vision is the primary mechanism for depth perception in many animals, including humans, other cues also contribute. These monocular cues include relative size, occlusion, linear perspective, and texture gradients. These cues can be perceived with a single eye and are important for depth perception, especially when stereopsis is limited, such as in very close or very distant objects, or for individuals with strabismus or amblyopia. The combination of stereoscopic vision and monocular cues provides a robust and comprehensive understanding of the three-dimensional world.