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
Animal Eye Movements
The brain receives visual information about the environment through photoreceptors in the retina, which convert light into electrochemical signals and ultimately into neural activity. This entry describes various experiments on animal eye movements. The spatial orientation of the retina with respect to objects in the world determines what kind of visual information is perceived. Therefore, in all mobile animals the position of the retina with respect to visual objects of interest must be controlled, to ensure that they are aligned and that the retina is stationary with respect to such objects long enough for visual inspection. An interesting exception are heteropod mol-lusks, which have eyes that are shaped as a long narrow stripe only three to six receptors wide and several hundred receptors long. Their visual field of view is only a few degrees high and 80 to 180 degrees long. At any given time, therefore, most of the surroundings ...