Sügavustunnet

Sügavustunnet, also known as stereopsis, is the visual perception of depth and three-dimensionality. It is a crucial aspect of our visual system, allowing us to navigate our environment, judge distances, and interact with objects. This perception is primarily achieved through binocular vision, meaning the brain combines the slightly different images received by each eye.

The difference between the images from the two eyes is called binocular disparity. The brain analyzes this disparity to calculate the distance of objects. Objects closer to the viewer will have a larger disparity than objects farther away. This process is highly effective for judging distances of objects within a few meters.

While binocular disparity is the primary mechanism for stereopsis, other cues also contribute to depth perception. These monocular cues include relative size, linear perspective, interposition (occlusion), texture gradient, and atmospheric perspective. For example, objects that appear larger are often perceived as closer, and parallel lines converging in the distance suggest depth.

Conditions that impair binocular vision, such as strabismus (misaligned eyes) or amblyopia (lazy eye), can significantly affect a person's ability to develop normal stereopsis. In such cases, the brain may rely more heavily on monocular cues, leading to a less precise or absent sense of depth. Testing for stereopsis is a common part of an eye examination.