Neurologists from Sweden and the United Kingdom in their study focused on the so-called the third eye and came to the conclusion that his remains are still found in the human body today. However, it is not a true chamber eye, but the third eye is the pineal gland (pineal body), which is hidden inside the brain and helps regulate sleep.
According to the results published in the journal Current Biology, distant human ancestors used a light-sensitive structure in the middle of the head about 500 million years ago. According to scientists the invertebrates of that time gradually lost their normal eyes while living underground and relied more on this organ.
Today, the pineal gland itself cannot perceive light, as it is located in the center of the brain. However, it still receives information about light and dark through the eyes and helps control biological processes. The body produces the hormone melatonin, which signals to the body that it is time to rest. It thereby contributes to the regulation of the circadian rhythm, i.e. the approximately 24-hour cycle of the body.
“The need to know what time of day it is or where it’s up and down if you’re in deep water hasn’t gone away. We therefore think that many millions of years ago the original eyes were lost, but the original central eye remained because it was good at this discrimination,” said research leader Thomas Baden. The authors claim that the results change the previous view of the development of this organ and suggest that the human retina and pineal gland have a common evolutionary origin.
