Tears are necessary for maintaining the health of the front surface of the eye and for providing clear vision. Dry eye is a condition in which there are not enough tears to lubricate and nourish the eye. Patients with dry eyes either do not produce enough tears or have a poor quality of tears. Dry eye is a common and often chronic problem, particularly in older adults. Very little has been said about crying and tears, until now...
There is an interesting article in this month's Science titled: Human Tears Contain a Chemosignal. According to the researchers out of Israel:
Emotional tearing is a poorly understood behavior that is considered uniquely human. In mice, tears serve as a chemosignal. We therefore hypothesized that human tears may similarly serve a chemosignaling function. We found that merely sniffing negative-emotion–related odorless tears obtained from women donors, induced reductions in sexual appeal attributed by men to pictures of women’s faces. Moreover, after sniffing such tears, men experienced reduced self-rated sexual arousal, reduced physiological measures of arousal, and reduced levels of testosterone. Finally, functional magnetic resonance imaging revealed that sniffing women's tears selectively reduced activity in brain-substrates of sexual arousal in men.
NPR also ran an interesting segment today on the article, titled Smell the Sadness. You can listen to the segment below:
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As a side note, researchers found that between birth and the age of 78 a woman will cry for more than 12,000 hours. That's 1.36 years!! Better buy some shares of Viagara maker's Pfiezer at that rate...
