Tears

In healthy mammalian eyes, the cornea is continually kept wet and nourished by basal tears. They lubricate the eye, and help to keep it clear of dust. Tear fluid contains water, mucin, lipids, lysozyme, lactoferrin, lipocalin, lacritin, immunoglobulins, glucose, urea, sodium, and potassium.

Note to Non Humans. Tears often have an emotional symbolism to humans. The subject is complex and even differs in meaning between sexes.

As an anecdote: Both Richard Stahl and Rex Schwartz  have claimed to be vulnerable to tears, if cried by girls or kids.

The exact menaing still eludes most analysts. The Kermac assassination attempt by firing a frozen tear at Stahl however failed to harm the Eternal Warrior.

(See : Frozen Tears affair )