Are tears structurally or chemically different depending on the reason for crying?

Question

An artist named Rose-Lynn Fisher has made photos of human tear drops under a microscope, and shows them to be different in their structure depending on how those tears were generated. Sad tears have a different appearance on a molecular level than happy tears, and so on.

Unlike the notorious work of Masaru Emoto, who claimed that people's attitude towards water changed that water's molecular structure, the ideas of tears being different seems at least partially plausible. A person who was sad might have different hormones or levels of adrenalin, for example, than a person who was happy. Could some internal difference in the person crying find its way into the tears in any way that was observable?

However, even though the artist claims to have used "tools of science", it also seems equally likely that the artist has simply chosen from a wide sample of random images available from each set of tears and selected the ones that she felt matched her narrative.

As art, it's nice enough. As science... is there anything to it? Could tears be physically different depending on the reason the human produced them? Is there any research the demonstrates what the differences are and why?

Answer 1

It seems to be.

According to Wikipedia :

In a research conducted by the Weizmann Institute of Science in Rehovot, Israel, emotional tears from women have been found to reduce sexual arousal in men. Also, emotional tears are made up of a different chemical component than those evoked by eye irritants and can relay chemical messages to others.[14] The change in sex drive could be attributed to a drop in testosterone provoked by the tear chemicals, reducing aggression. In the animal world, it has been found that some blind mole rats rub tears all over their bodies as a strategy to keep aggressive mole rats away.[15]

Tear composition varies from tear types. Mainly, tears are composed of water, salts, antibodies and lysozymes (antibacterial enzymes). According to a discovery by Dr. William H. Frey II, a bio-chemist from St. Paul Ramsey medical center in Minnesota, the composition of tears caused by emotion differs from that of tears as a reaction to irritations, such as onion fumes, dust or allergy. Emotional tears are composed of more protein-based hormones, such as prolactin, andrenocorticotropic, and leucine enkephalin (a natural pain killer), which is suggested to be the mechanism behind the experience of crying from emotion making an individual feel better.[16]

• [14] Weaver,Janelle. Crying Women Turn Men Off”. Scientific American Mind, May/June 2011, p. 22, 6.
• [15] Dell'Amore, Christine. " Women's Tears Reduce Sex Drive in Men, Study Hints", “National Geographic, January 6, 2011, accessed June 6, 2011.
• [16] Am J Ophthalmol. 1981 Oct;92(4):559-67