The Caenorhabditis elegans worm detects ultraviolet light, although it has no eye. C. elegans is a highly studied laboratory animal, but having no eye and a very simple nervous system, researchers have believed that it has no sensitivity to light. However, when illuminated with UVA, the worm moves to escape this light. Researchers believe that this discovery may have something to do with investigating the evolution of the structure of the eyes of animals.