Pub. date: 2010 | Online Pub. Date: December 16, 2009 | DOI: 10.4135/9781412972000 | Print ISBN: 9781412940818 | Online ISBN: 9781412972000| Publisher:SAGE Publications, Inc.About this encyclopedia
Eye Movements: Behavioral
Eileen Kowler & Han Collewijn
Movements of the eyes are crucial for being able to see a clear and sharp image of the world. Understanding why this is the case requires considering some facts about vision. An optical image of the visual environment is formed on the retina of each eye, much like the image in a digital photographic camera. Because of properties of both the retinal receptors and the brain, the quality of human vision is inhomogeneous across space. Visual resolution is best in a small, central portion of the retina (the fovea ), and falls steeply toward the periphery. Movements of the eyes are used to bring images of interesting objects to the fovea, where they can be seen with optimal clarity. Movements of the eye are also responsible for ensuring that the selected images do not leave the fovea, or move across the retina too rapidly, each time the head moves. These ...