“Perception is the process by which we recognise what is represented by the information provided by our sense organs” (Sarma, 2010). As well as our ability to perceive the shape of the objects, we are also able to judge its location and its movements. Perceiving the location of things and their movements are all important roles of the visual system (Decety et al., 1997; Jeannerod, 1997 in Sarma, 2010).
Depth perception requires that we measure the distance between us and the objects in the environment .Our ability to do this is aided by two types of cues: binocular (two-eyes) and monocular (one-eye) (Sarma, 2009). With binocular cues the eyes make conjugate movements so that they converge at the same point on the object (Sarma, 2009). Binocular vision is the part of the vision system which uses two eyes (Entzinger, 2009). It is the opposite of monocular vision, in which only one eye is, utilized (Entzinger, 2009). Convergence plays an important role for perceiving the distance of objects especially the distance of objects that are near hand to us (Sarma, 2009). Our eyes will be turned slightly inward when an object is in close proximity to our face, however when an object is further away our eyes tend to look straight ahead (Sarma, 2009).
Retinal disparity and stereopsis also play other important roles in the perception of distance.
Stereopsis is concerned with the perception of depth based on horizontal binocular parallax, which is a change in the way of viewing because of the existence of horizontally separated eyes (Wheatstone, 1938 as in Patterson, 2009). Binocular disparity evolves from binocular parallax, which is a change in the position of similar images that stimulate the two retinas       (Patterson, 2009). Binocular cues have many benefits and one of which can be seen in the landing of aircrafts. Depth and distance perception are all important factors when landing a plane. “Stereopsis is considered an important depth cue especially for close range...