Shrews have a very high metabolism and spend most of the day and night hunting for food. Subterranean worms and insects are their main prey, which means that a lot of their time is spent in tunnels, where there is little, if any, light. Consequently, shrews have little need for large eyes or excellent vision, neither of which they have.
While the sight of most shrews is probably limited to the detection of light, some species compensate by using other senses, including hearing and touch, to direct them. The Short-tailed Shrew has a well-developed repertoire of squeaks and clicks, including ultrasonic sounds, for navigation and predation. (photo: hair has been brushed aside in order to see eye slit)