Human beings have a remarkable ability of making accurate distance judgments based on the images that form on the retina of the eyes. More specifically, humans can extract depth information from the retinal images, which are usually two-dimensional (2D) or rather depthless (Blake & Sekuler, 2006; Eysenck, 2002; Snowden et al., 2012). However, it is important to note that the process of visual perception is much more complex in that the 2D retinal images must be perceived as three-dimensional (3D) spatial representations (Barbato & Addington, 2013; Fischmeister & Bauer, 2006). In order to achieve this level of visual perception, the human visual system must receive and interpret information from different sources including monocular and binocular cues to depth. Depth cues or pointers are important source of information, which enable the human visual system to re-construct 3D images from flat or 2D retinal images (Blake & Sekuler, 2006; Fischmeister & Bauer, 2006).
However, contrary to other categories of cues, the cues to depth do not elicit any form of conscious deliberation in order for depth to be perceived, but rather depth perception occurs without any effort or thought (Blake & Sekuler, 2006). Actually, human beings achieve accurate judgment of distances based on the coordination of depth information from various sources, which usually operate harmoniously in such a way that they manage to create an unambiguous 3D image out of the flat, 2D retinal images (Blake & Sekuler, 2006; Snowden et al., 2012). This essay seeks to define precisely the concept of depth perception and highlight the different sources of depth information with particular emphasis on monocular and binocular cues to depth. Based on the following discussions, it will become apparent that binocular depth perception is as important as monocular depth perception, but the former is much more advantageous when it comes to the perception of certain depths, which are beyond the scope of monocular cues.
Definition of Depth Perception
In precise terms, depth perception is a term used to refer to two different ways by which human beings make accurate judgements of distance in space. First, depth perception refers to the distance between an observer and an object, which is also known as absolute or egocentric distance (Blake & Sekuler, 2006; Sridhar & Bedell, 2011). This form of depth perception is particularly relevant in baseball and basketball whereby the shooter must make accurate judgments of the distance between the ball’s destination and their current position (Blake & Sekuler, 2006). On the other hand, depth perception may refer to relative distance, which is the distance between two different objects or between two points occurring on the same object. Apart from referring to different types of distances, the two categories of depth perception are quite different in that they employ different sources of depth information to make accurate judgments of distance (Blake &...