Vision

Vision is easy. All an observer has to do is open his or her eyes and look around. Doing this reveals visual qualities in the environment such as shapes, light, colors, objects at specific locations, spatial layout, movement, and surface textures. This gamut of experience is created by two small detectors (eyes) connected to a powerful computer (the brain), which combine to transform the light reflected from objects first into images on the retina, then into activity in the brain, and finally into the perceptions we experience.

The transformation of environmental stimuli into an image on the retina creates a situation that could be interpreted to indicate that the mechanism for vision is simple. According to this interpretation, if stimuli are represented as a picture on ...