Eyes are a “window to the soul,” but what about a window to the brain?
Experts suggest that mental health can be closely linked to eye health, and research also shows how eyes can be used to detect mental health issues.
Dr. Jeffrey Anshel, an optometrist and president of the Ocular Nutrition Society, said in an email that there is one noticeable link between the eyes and brain. Research shows that carotenoids, such as lutein and zeaxanthin, are shared over the blood-brain barrier and end up accumulating in the brain.
Carotenoids are natural pigments found in plants, and the two mentioned above are considered to be good for eye health.
He said that lutein and zeaxanthin can gather in the central part of the retina, which is where we get our vision from. These carotenoids play a major role in maintaining 20/20 vision, and people with macular degeneration generally have lower amounts of both caotenoids in their retinas.
“[Macular degeneration] doesn't cause ‘total’ blindness, but people can't see what they’re looking directly at; for example grandparents can't see their grandchildren's faces,” Anshel said. “Thus, this disease is more ‘frustrating’ than it is ‘blinding.’ This, of course, can lead to mental anguish and other related psychological issues.”
Two different studies also show just how eyes can be a window into mental health. A 2003 study at the University of Illinois at Chicago demonstrated that eye movements can be used to detect mental illnesses, since irregular eye movements can suggest abnormal functioning in the brain.
Researchers stated that people with schizophrenia tend to have problems following slow-moving objects with their eyes.
University of Aberdeen also has a similar research project where they devised an eye test to detect mental illnesses such as bipolar disorder, schizophrenia and depression, according to the university’s website.