Biochemist William Frey has spent 15 years studying tears and why we cry. His team of scientists have found that, although tear production organs were once thought to be unimportant and no longer necessary for survival, tears actually have numerous critical functions.
Tears are an emotional response which only humans have, for only people are known to weep. While all animals produce tears to lubricate their eyes, only human beings possess the extensive system that causes us to cry.
Tears are secreted by your lacrimals—tiny, sponge-like glands which rest above the eye against the eye socket. The average person blinks every two to ten seconds. With every blink, the eyelid carries this fluid over your eye’s surface.
One of the most obvious functions of tears is to lubricate your eyeball and eyelid, but they also prevent dehydration of your various mucous membranes, as anyone with ‘dry eye’ problems can attest to. A severe lack of lubrication produces a condition requiring medication or therapy to save the victim’s eyesight.
Another important function of tears is that they bathe your eyes in lysozyme, one of the most effective antibacterial and antiviral agents known to man. Amazingly, lysozyme inactivates 90 to 95 per cent of all bacteria in a mere five to 10 minutes. Without it, eye infections would be much more common and serious.
One amazing discovery is that tear production may actually aid a person in dealing with emotional problems. Scientific studies have found that after crying, most people do feel better, and those that suppress their tears do feel worse.
Not unexpectedly, those who suffer from the inherited disease familial dysautonomia not only cannot cry tears, but also have a lesser ability to deal with stressful events in their lives.
In a recent study, tears caused by simple irritants were compared to those brought on by emotion. Researchers found that stress-induced tears actually remove toxic substances from the body. Volunteers were led to cry first from watching sad movies, and then from freshly cut onions. The researchers found that the tears from the movies contained far more toxic biological byproducts. Weeping, they concluded, is an excretory process which removes toxic substances that normally build up during emotional stress.
The simple act of crying also reduces the body’s manganese level, a mineral which affects mood and is found in up to 30 times greater concentration in tears than in blood serum. They also found that emotional tears contain 24 per cent higher albumin protein concentration than tears caused by eye irritants.
The researchers concluded that chemicals built up by the body during stress were removed by tears, which actually lowered stress. These include the endorphin leucine-enkephalin, which helps to control pain, and prolactin, a hormone which regulates milk production in mammals.
They found that one of the most important of those compounds which removed tears was adrenocorticotrophic hormone (ACTH), one of the best indicators of stress. Suppressing tears increases stress levels, and contributes to diseases aggravated by stress, such as high blood pressure, heart problems and peptic ulcers.
Ashley Montagu concluded that weeping contributes not only to the health of the individual, but also to the group’s sense of community because ‘it tends to deepen involvement in the welfare of others’.
Tears are an extremely effective method of communication, and can elicit sympathy much faster than any other means. They effectively relate that you are sincere about a certain concern, and anxious to deal with the problem.
What can we learn from all this? That the seemingly simple and common response of producing tears is enormously complex and, indeed, is an integral and necessary part of being human. Without tears, life would be drastically different for humans—in the short run enormously uncomfortable, and in the long run our eyesight could be jeopardized.
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