ABSTRACT
Vision is the quintessential “distance” sense.* Barring any physical obstructions or opacities, the eye can detect light radiating from stars that loom billions of miles away-on a clear moonless night the Andromeda galaxy can be viewed from 2.5 million light years, or 15 million-trillion miles, away. These cosmic numbers also highlight the speed of vision: at light-speed rates of transmission there is no faster way to communicate information about objects in the environment. These sensory attributes easily outclass the senses of smell and hearing, which operate over shorter spatial ranges and slower temporal scales (see chapters by Gottfried and Wilson and by Camalier and Kaas for further ecological considerations of these other senses).
