Eccentricity (as used in sensory and perceptual psychology) is a term used to describe the varied responses to light across the retina of the eye. The retina contains rods and cones which are photoreceptor cells. These are cells which are specialized and convert light into signals which are sent to the brain. These signals are eventually converted into images by our brain making rods and cones essential for us to see. Eccentricity occurs because there are differing amounts of rods and cones on each part of the retina.