pineal eye

Origin of pineal eye

First recorded in 1885–90
Also called third eye.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for pineal eye

pineal eye

noun
  1. an outgrowth of the pineal gland that forms an eyelike structure on the top of the head in certain cold-blooded vertebrates
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

pineal eye in Science

pineal eye

[pĭnē-əl, pīnē-əl]
  1. 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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.