tears, watery secretion of the lacrimal gland, which is located at the outer corner of the eye socket immediately above the eyeball. Tearing, or lacrimation, is a continuous and largely involuntary process stimulated by the autonomic nervous system. Fluid is secreted into the lacrimal lake, the area between the eyeball and the upper eyelid, and spread across the surface of the eye by blinking. Tears serve to bathe and lubricate the cornea, the sensitive outer covering of the eyeball. Typically, the fluid either evaporates or is drained off through tiny canals at the inner corner of the eye, but in times of excessive tearing the apparatus is overwhelmed and tears overflow the eyes.
See T. Lutz, Crying: The Natural and Cultural History of Tears (1999).
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
See more Encyclopedia articles on: Anatomy and Physiology
Browse By Subject
- Earth and the Environment +-
- History +-
- Literature and the Arts +-
- Medicine +-
- People +-
- Philosophy and Religion +-
- Places +-
- Australia and Oceania
- Britain, Ireland, France, and the Low Countries
- Commonwealth of Independent States and the Baltic Nations
- Germany, Scandinavia, and Central Europe
- Latin America and the Caribbean
- Oceans, Continents, and Polar Regions
- Spain, Portugal, Italy, Greece, and the Balkans
- United States, Canada, and Greenland
- Plants and Animals +-
- Science and Technology +-
- Social Sciences and the Law +-
- Sports and Everyday Life +-