Eyesight is one of our most important senses. Almost 80% of what we perceive comes through our sense of sight.  In fact, a far larger part of the brain is dedicated to vision than to hearing, taste, touch, or smell combined. Healthy eyesight is a necessary input to healthy brain functioning. The brain is our most vital organ, allowing us to live complex lives. Good vision contributes to improved athletic ability, better driving skills, improved learning and comprehension and therefore leads to a better quality of life. Humans are fairly unique in their reliance on sight as the dominant sense. The dog’s nose tells it much more about its environment and who is in it than its eyes. In contrast, we can’t smell all the wildlife that visited our yard but we can see them in vivid color.

Large eyes are generally considered more favorable, according to Chinese face-reading beliefs. They are associated with intelligence and astuteness, apart from beauty. Eyes are said to be the windows to our souls, but do they also tell us about our intelligence? It has generally been observed that larger the pupil size, higher is the fluid intelligence. This may be because the brain systems which regulate pupil size are also responsible for switching the brain out of the resting default mode into action as one goes from darkness to light. This switching is something what intelligent people are more adept at doing.

Pupil size reflects something more than simply the amount of light entering the eye. Though, it was previously thought that pupil size is too crude a measure of brain activity but more recently, the discovery that activity in an area of the brain known as the locus coeruleus results in changes to pupil size has opened the possibility that pupil size could be a useful indicator of neural processing. The locus coeruleus is a part of the brainstem with connections across the rest of the brain, including the prefrontal cortex, which plays a crucial role in cognitive abilities such as memory and intelligence. In a new study, psychologist Jason S. Tsukahara of Atlanta U.S and colleagues have found a positive correlation between pupil size and cognitive ability. Therefore, it is not unlikely that pupil size may actually be a valuable reflection of neural activity and can be used to determine differences in cognitive ability in humans.

The physicist namely Hertz who presented a decisive experimental confirmation for Maxwell’s theory of electromagnetism in 1888 has put the significance of eyes in this following lines,  “The connection between light and electricity is established. In every flame and in every luminous particle, we see an electrical process. Thus the domain of electricity extends over the whole nature. It even affects ourselves intimately because we perceive what we possess, an electric organ – the eye”

According to Jane Eyre, the soul fortunately has an interpreter – often an unconscious but still a faithful interpreter  in the eye.  Eyes do reveal a lot about a person.  “Where words are restrained, the eyes often talk a great deal.” It is for the same reason that poker players often cover their eyes with sunglasses for fear of giving a tell. Much of our non-verbal communication comes from the way we listen and express ourselves through our eyes. ‘Ankhein’, the 1968 blockbuster of Indian Cinema is considered to be a pioneer in Hindi spy films. Its title song outlines the significance of eyes in the following lyrics

us mulk ki sarhad ko koi chhu nahi sakta
jis mulk ki sarhad ki nigeban hai ankhe
har tarah ke jajbat ka alan hai ankhe
sabnam kabhi shola kabhi tufan hai ankhe
ankho se badi koi taraju nahi hoti
ghulta hai basar jisme wo mijan hai ankhe
lab kuchh bhi kahe usse hakikat nahi khulti
insan ke sach jhuth ki pehchan hai ankhe

Our eyes reflect our moods and to some degree, our health and well-being. There are times when we notice a person is under-the-weather by solely looking into their eyes. According to Daily Mail, Swedish scientists have discovered that patterns in the iris can give an indication of whether we are warm and trusting or neurotic and impulsive.  In his context, William R Alger, an American writer of 19th century has put his observations in the following lines,

A gray eye is a sly eye, And roguish is a brown one;

Turn full upon me thy eye, Ah, how its wavelets drown one!

A blue eye is a true eye; Mysterious is a dark one,

This flashes like a spark-sun!  A black eye is the best one.

Doctors generally diagnose other bodily diseases by examining the eyes. This is because the eye is the only place in the human body where neural tissue and blood vessels can directly be seen.  An eye examine can uncover diabetes, high blood pressure, infections, and even auto-immune disease. The practice of eyelids closure immediately after death is common in many cultures, since eyes are believed to be watching the free set soul.  Therefore, closed eyes at the time of death are associated with peacefulness and restfulness, and open eyes with discomfort or even fear.  However, there is virtually no modern literature on the prevalence of this practice, or the causes of open eyelids post-mortem.

Dr. Qudsia Gani is Assistant Professor, Department of Physics, Cluster University Srinagar