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:
“People forget that it is the eye that makes the horizon, and the rounding mind’s eye which makes this or that man a type or representative of humanity with the name of hero or saint.”
—Ralph Waldo Emerson (1803–1882)
“Physical pleasure is a sensual experience no different from pure seeing or the pure sensation with which a fine fruit fills the tongue; it is a great unending experience, which is given us, a knowing of the world, the fullness and the glory of all knowing. And not our acceptance of it is bad; the bad thing is that most people misuse and squander this experience and apply it as a stimulant at the tired spots of their lives and as distraction instead of a rallying toward exalted moments.”
—Rainer Maria Rilke (1875–1926)