In psychology, monocular cues are how people can perceive depth through the word around them. Light and shadows are monocular cues because when light falls on an object, it will present a shadow.
Relative height is also one. It occurs when two objects look the same height, but the one closest to the person will look taller. Interposition is a monocular cure and occurs when two objects are overlapped on one another and the one obscured is seen as far away — knowing that these three are monocular cues, that leaves retinal disparity, which is just when our eyes view images differently.