What are tears made of ?

Tears play an important role in keeping us healthy. To clean and lubricate the eyes tears play an important role. Tears keep the surface of our eyeballs clean and moist, and help protect our eyes from damage. The production or shedding of tears is also known as Lacrimation or Lachrymation. Although they make appear to be nothing more than water, our tears are actually complex. Tears are made of mucus, water and oil. Mucus coats the surface of the eye and helps to bind the tear layer to the eye.

                                 
In the absence of healthy mucus layer, dry spots are formed on the cornea. The water is more of a saline solution that contains vitamins and minerals vital to normal cell function. The oil of the tears prevent evaporation of the tears. Some people do not make enough oil resulting in dry eyes. If the oil component is not normal then the tears evaporate too quickly.
Our tears also contain natural antibiotics called lysozymes. These antibiotics fight against bacteria and viruses.
Types of tears :


1. Basal tears -
These tears continually keep the cornea of the eyes wet and nourished. They lubricate the eyes and help to keep it clear from the dust. Usually in a 24-hour period, 0.75 to 1.1 grams of tears are produced and the rate decreases with age.

2. Reflex tears -
These tears result from the irritation of the eyes by the presence of irritant substances such as onion vapors, tear gas, pepper spray in the eye's environment. These are also linked with vomiting, coughing and yawning. These reflex tears attempt to wash out irritants that may have come into contact with the eye.

3. Psychic tears -
These tears are referred to as crying or weeping. These are produced due to strong emotional stress, anger, suffering or physical pain. The chemical composition of these tears is little different than those required for the lubrication.

Artificial tears -
Artificial tears are lubricant eye drops used to treat dryness and irritation caused by reduced tear production, as in case of dry eye syndrome. These are also used during medical examinations and to moisten contact eye lenses. These are produced to mimic the natural tears as closely as possible. They contain water, salts and polymers, but lack proteins which are found in natural tears.