Depth perception relies on a variety of visual signals to interpret the three-dimensional world from two-dimensional retinal images. One category of these signals involves information available to each eye independently. These are visual clues that provide depth information using only one eye. These cues include size constancy, relative size, texture gradient, interposition, and linear perspective. For example, when viewing a road, the parallel lines of the road appear to converge in the distance, providing an impression of depth.
Understanding how the visual system processes these independent cues is fundamental to comprehending spatial awareness and navigation. Historically, the study of these single-eye depth indicators has informed artistic techniques, leading to more realistic representations in paintings and other visual media. This understanding also has practical implications for designing virtual reality environments and assisting individuals with impaired binocular vision.