Animals that are naturally blind include the star-nosed mole, blind cave fish, Texas blind salamander and Salem cave crayfish. Some of these animals, such as the mole, have eyes that don't function, while others don't have eyes at all.
PBS points out that star-nosed moles are blind for all intents and purposes. However, they have a group of star-shaped tentacles on the end of their noses that give them a great sense of touch. Scientists believe that moles are even able to detect electrical fields.
The other three blind animals actually lack eyes. For instance, blind cave fish live in deep caves where light doesn't reach. To survive they bounce sound waves off objects and listen for the echoes, a form of sonar akin to that of bats.
Texas blind salamanders lives in underground water caves, where eyes are useless. Instead of eyes, they have black dots. These have a natural sensitivity to pressure waves, which enables the salamanders to catch prey consisting largely of snails and shrimp.
Like blind salamanders, Salem cave crayfish also thrive in subterranean waters and live exclusively in the Missouri Ozarks. These creatures boast the physical characteristics of most species of crayfish: pincers and antennae. They just lack functioning eyes.