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: Invertebrate Photoreceptor
Famous quotes containing the words eye and/or spots:
“Mine eye and heart are at a mortal war,
How to divide the conquest of thy sight;
Mine eye my heart thy picture’s sight would bar,
My heart mine eye the freedom of that right.”
—William Shakespeare (1564–1616)
“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)