Ocelli or Eye Spots
Jellyfish, sea stars, and flatworms bear the simplest eyes, pigment spot ocelli, which have pigment distributed randomly and which have no additional structures such as a cornea and lens. The apparent eye color in these animals is therefore red or black.
Many snails and slugs (gastropod mollusks) also have ocelli, either at the tips or at the bases of the tentacles. However, some other gastropods, such as the Strombidae, have much more sophisticated eyes. Giant clams (Tridacna) have ocelli that allow light to penetrate their mantles.
Read more about this topic: Simple Eye In Invertebrates
Famous quotes containing the words eye and/or spots:
“The eye is the lamp of the body.”
—Bible: New Testament, Matthew 6:22.
“The instincts of merry England lingered on here with exceptional vitality, and the symbolic customs which tradition has attached to each season of the year were yet a reality on Egdon. Indeed, the impulses of all such outlandish hamlets are pagan still: in these spots homage to nature, self-adoration, frantic gaieties, fragments of Teutonic rites to divinities whose names are forgotten, seem in some way or other to have survived mediaeval doctrine.”
—Thomas Hardy (1840–1928)