The miracle of tears
Photo by Joy Luke
The girl with a tear running down her cheek, has won several photography awards (photographic judges are emotional too!).
Evidence of our Creator is all around us—from the miracle of the atom’s intricate internal structure, to the design of the most complex piece of matter in the universe, the human brain. Scientists have found God’s greatness even in one of the most minute phenomena—human tears.
Biochemist William Frey spent many years as head of a research team studying tears. The team found that, although tear production organs were once thought to be vestigial (left over from evolution) and no longer necessary for survival, tears actually have numerous critical functions.1
Emotional tears are a response which only humans have, for only people can weep. All animals that live in air produce tears to lubricate their eyes. But only people possess the marvellous system that causes crying.2
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 miracle 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—and anyone with the ‘dry eye’ problem knows how painful this can be. A severe lack of this lubrication produces a condition requiring medication or therapy to save the victim’s eyesight. A thin layer of oil on the exposed eye reduces evaporation of tears, keeping eye tissue moist and soft.3 This oil is produced in your Meibomian glands located in the eyelids.
Another important function of tears is that they bathe your eyes in lysozyme, one of the most effective antibacterial and antiviral agents known. Lysozyme, from lysos, to split, and enzyme (it is an enzyme which chemically splits certain compounds) is the major source of the antigerm traits of tears. Amazingly, lysozyme inactivates 90 to 95 per cent of all bacteria in a mere five to 10 minutes.4 Without it, eye infections would soon cause most victims to go blind.
Cry and feel better
One amazing discovery is that tear production may actually be a way to aid a person to deal with emotional problems. This finding lends some basis to the expression, “To cry it out helps a person feel better”. Scientific studies have found that after crying, people actually do feel better, both physically and physiologically—and they feel worse by suppressing their tears.2
Not unexpectedly, those who suffer from the inherited disease familial dysautonomia not only cannot cry tears, but also have a very low ability to deal with stressful events.4
Photo by Paul Salmon
Emotional tears, caused either by laughing or crying, are a response which only humans have, for only humans can weep.
At the St Paul Ramsey Medical Center in Minnesota, tears caused by simple irritants were compared to those brought on by emotion. Researcher William Frey found that stress-induced tears actually remove toxic ‘substances’ from the body.5 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, called emotional tears, 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.2
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.3
Aid to health
Ashley Montagu concluded that weeping contributes not only to the health of the individual, but also to the group’s sense of community and that “it tends to deepen involvement in the welfare of others”.4 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.
Tears can be brought on not only by strong emotions, but also by mechanical irritation of your eye, infections, or illness. Reflex or irritation weeping appears to be ‘designed … as an emergency … mechanism’ because the lacrimal glands automatically provide the proper level of lubrication and protection when needed.6
The reason that onions cause crying is because they release a chemical which turns into sulphuric acid on contact with the eye surface—a chemical which would damage your eyes enormously if it were not for the tear reflex which renders the suphuric acid almost harmless.
Tears normally flow constantly, and are effectively drained into the lacrimal punctum, visible as a small dot at the nasal border of the lower eyelid. The visible flow of tears on the cheeks is caused by a tear production that is greater than the drainage system can handle, causing the overflow to run down the cheek.
Tears constantly bathe each of your corneas (the transparent ‘windows’ of the eyes). This not only prevents your eyes from drying out (which can cause blindness if not corrected) but it can help greatly in washing out foreign bodies such as dust, which is an omnipresent part of air.7 As one author notes, ‘The importance of tears can best be recognized by seeing what happens when someone does not have them.’6
Not being able to secrete enough tears produces burning and redness, and light itself becomes bothersome. The eyes itch and have a gritty feeling. One sufferer described the condition as similar to having sand in the eye. In time, ulcers develop on the cornea and loss of its transparency often occurs.
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 the miracle called the human body. Without tears, life would be drastically different for humans—in the short run enormously uncomfortable, and in the long run eyesight, so important for everyday life, would be blocked out altogether.
Tears are just one of many miracles which work so well that we take them for granted every day. And it is one more reason to realize that our marvellous body is not the result of evolutionary trial and error.
References and notes
- Frey, W., Crying: The Mystery of Tears, Winston Press, Texas, 1977. Return to text
- Levoy, G., Tears that Speak, Psychology Today 22(7-8):8–10, 1988. Return to text
- Wertenbaker, L., The Eye: Window to the World, Torstar Books, New York, 1984. Return to text
- Montagu, A., The Evolution of Weeping, Science Digest, p. 32, November 1981. Return to text
- Kovach, T., Tear Toxins, Omni, December 1982. Return to text
- Freese, A., The Miracle of Vision, Harper and Rowe Publishers, New York, p. 19, 1977. Return to text
- Kennedy, C.C., Tears: Medical Research Helps Explain Why You Cry, Mayo Clinic Health Letter, pp. 4, 5, February 1992. Return to text
Following her stroke my mother lost her ability to cry. She feels sadness and wants to cry but cannot generate the tears. Apart from having no feeling on her left side and her inability to cry she is her normal self.
So according to evolution, humans evolved the ability to talk, the desire to talk, the ability to cry when sad, the ability to walk and we lost most of our hair.