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The Science of Tears

Eye Tear GlandsWhen was the last time you had a good cry? Shedding tears may be healthier than you thought, and the secret lies in the chemical composition of tears.

Tears are continually produced in small quantities by the Tear Glands, which are located on the outer side of each eye, slightly above the eye and underneath the eyelid. Tears, which are spread evenly over the front surface of the eye during blinking, clean and lubricate the eye. An important component of tears is lysozyme, a chemical that inhibits bacterial growth on the eye's surface. Some of the tears evaporate, but the remainder are drained into the nose through the Tear Duct, keeping the nose moist. Lysozyme from the tears prevents bacterial growth in the nose as well.

Another interesting discovery about the content of tears was made by Dr. William H. Frey II, a biochemist at the St. Paul-Ramsey Medical Center in Minnesota. He and his team analyzed two types of tears: the emotional ones (crying when emotionally upset and stressed) and the ones arising from irritants (such as crying from onions). They found that emotional tears contained more of the protein-based hormones, prolactin, adrenocorticotropic hormone, and leucine enkephalin (natural painkiller), all of which are produced by our body when under stress. It seems as if the body is getting rid of these chemicals through tears. That explains why we usually feel better after a good cry. So, there you go. Cry as much as you want - it is probably good for you. But no cheating by inducing crying with onions. Your tear glands know the difference.


About the Author

Anton Skorucak, MS

Anton SkorucakAnton Skorucak is a founder and publisher of ScienceIQ.com. Anton Skorucak has a Master of Science (MS) degree in physics from the University of Southern California, Los Angeles, California and a B.Sc. in physics with a minor in material science from the McMaster University, Canada. He is the president and creator of PhysLink.com, a comprehensive physics and astronomy online education, research and reference web site.