Your Invisible Eye
Did you know that you have three eyes? In fact, someday your third eye may provide spare parts that might be necessary to repair the two eyes you normally think about.
Scientists have known for more than a century that the western fence lizard has a third eye. Its third eye can be seen as a white spot on the top of its forehead. While this third eye is an extension of the pineal gland, it has a retina, lens and cornea. While this third eye is unable to focus light, it does sense light. Pineal eyes are also found in other lizards, frogs and lampreys, but not in mammals. Since human beings are supposed to be evolutionarily closer to mammals, scientists did not expect to find the third eye in human beings.
However, when medical researchers investigating the human pineal gland compared their findings with eye researchers, they were astonished. Both the pineal and the retina make melatonin, an important chemical in our daily rhythm that also affects mood. Your pineal also makes a number of proteins that were thought to be made only by the eye that are necessary for processing light. And like the pineal, the eye also serves as one of the body's time-keeping mechanisms. There are so many similarities between the eye and the pineal in humans that scientists hope to one day use a person's pineal as a source of genetic spare parts to treat some eye diseases!
That scientific advance might have already been made if scientists had long ago given up their belief in evolution.