TEARS IN YOUR EYE

Tears are the liquid product of a process of crying to clean and lubricate the eyes. The word lacrimation,(from L. Lacrima meaning Tear) which can be also spelled as lachrimation, may also be used in a medical or literary sense to refer to crying. Strong emotions, such as sorrow or elation may lead to crying. The process of yawning may also result in lacrimation. Although most land mammals have a lacrimation system to keep their eyes moist, humans are the only mammal generally accepted to cry emotional tears.

WHAT'S IN A TEAR?
Tear fluid contains water, mucin, lipids, lysozyme, lactoferrin, lipocalin, immunoglobulins, glucose, urea, sodium and potassium. Some of the substances in lacrimal fluids(such as lysozyme) fight against bacterial infectin as a part of the immune system. Lysozymes does this by dissolving the outer coating of certain bacteria. It is a typical body fluid with a salt content similar to blood plasma.

TEAR TYPES
Basal Tears is the tear that continually keeps the cornea wet and nourished. It lubricates the eye, and help to keep it clear of dust.

Reflex Tears is the tears that is produced when the eye gets irritated by foreign particles, or from the presence of irritant substances such as onion vapors, tear gas or paper spray in the eyes environment, including the cornea, conjunctiva, or nasal mucosa. It can also occur with bright light and hot or peppery stimuli to the tong and mouth. It is also linked with vomiting. These tears attempt to wash out the irritants that may have come into contact with the eye.

Emotional Tears this is the increased lacrimation due to strong emotional stress, suffering, mourning or physical pain. this practice is not restricted to negative emotions; many people cry when extremely happy. In humans, it can be accompanied by reddening of the face and sobing - cough-like, convulsive breathing, sometimes involving spasms of the whole upper body. Tears brought about emotions have a different chemical make up than those for lubrication; for it contain more of the protein-based hormones prolactin, adrenocorticotropic hormone, and leucine enkephalin (a natural painkiller) than basal or reflex tears.

ONION TEARS
The substance in onions that makes us cry, is a gas called propanethiol-S, which is released into the air when a fresh onion is cut. When this gas reaches the eye, it combines with the water in the eye to form a weak acid. This acid irritates the eye and causes the lachrymal, or tear-producing glands, to fill the eye with tears in an effort to wash the acid away.

TEAR CULTURE
In nearly all cultures, crying is seen as specific act associated with tears trickling down the cheeks and accompanied by characteristic sobbing sound. Emotional triggers are most often anger and grief, but crying can also be triggered by sadness, joy, fear, laughter or humor, frustration, remorse or other strongly- experienced emotions. In many cultures, crying is associated with babies and children. Some cultures consider crying to be undignified and infantile, casting aspersions on those who cry publicly, except if it is due to the death of a close friend or relative. In most cultures, it is more socially acceptable for women and children to cry than men.

CROCODILE TEARS
It isn't true that a crocodile weeps crocodile tears for it has no tear glands. But the reptile does shed a tear-like eye secretion whenever it opens its mouth to gobble up a big victim, or whenever its jaws are forced far apart, just as our eyes water when we yawn. The phrase crocodile tears has come to mean tears shed or grief expressed in an insincere way, something the creature is mentally incapable of indulging in.

DO YOU KNOW THAT...

• When the Trigeminal nerve(the one that bears the sensory pathways of the tear reflexes) is cut, tears from reflexes will stop, but not emotional tears. Likewise, application of cocaine to the surface of the eye inhibits the reflex even under exposure to strong tear gases.
• A newborn infant has insufficient development of nervous control, so he/she "cries without weeping."
• Lest the cornea be damaged in surgery or other failure of lacrimal function occur, it is not a serious matter, for the accessory glands are enough for general secretion.
• Most mammals will produce tears in response to extreme pain or other stimuli, but crying as an emotional reaction is considered by many to be a uniquely human phenomenon, possibly due to humans' advanced self-awareness.
  
• Some studies suggest that elephants, gorillas and camels may cry as well.
• You'll shed less tears if you cut off last the root end of the onion. For that's where the irritating gas is mainly stored.
• Some modern therapy movements such as Re-evaluation Counseling teach that crying is beneficial to health and mental well-being, encouraging it positively.