|an outgrowth of the pineal gland that forms an eyelike structure on the top of the head in certain cold-blooded vertebrates|
|a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.|
|a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes.|
|pineal eye (pĭn'ē-əl, pī'nē-əl) Pronunciation Key
A sensory structure capable of light reception, appearing as a spot on the top of the head in lampreys, hagfish, amphibians, and some reptiles, especially the tuatara. Pineal eyes can contain a rudimentary cornea, lens, cone cells, and retina, and are thought to be sensitive to light and dark but not to be able to form images.