India, Sept. 18 -- A freshwater snail native to South America can regrow a complete camera-type eye after it is removed, with the eye bulb and stalk regenerating within about a month. The finding was reported in a study published in the journal Nature Communications, which examined the golden apple snail, Pomacea canaliculata.

What makes the snail worth studying is the kind of eye it has. Golden apple snails carry a camera-type eye, the same basic design found in every vertebrate, including humans, which is built around a closed chamber, a transparent cornea, a focusing lens, and a retina lined with light-sensing cells. Most animals known for regenerating body parts, such as flatworms or starfish, have far simpler eyes or none at all, so...