Tears

Tears formed on the surface of the corneal tear film. Its main function is to protect the eye and clean the surface of the eye, thus protecting the eye from infection. Tear film is important for the metabolism of the cornea and its nourishment. It is transparent and colorless, its volume is about 7 ml and the thickness is 4.5 to 8.7 micron and varies with time after blink.

Tear film has large surface tension, which prevents run-off of the water layer of the film. It consists of three closely related functional layers: outer - oil, medium - water and indoor - mucus.

Oil layer

The topmost part of the tear film and its main task is to protect the water layer from evaporating. It also moisturizes eyelids as they move across the eyeball.

Water layer

Adds atmospheric oxygen to corneal epithelium, has antibacterial effects, creating an optimal corneal smooth surface, allows the creation of sharp images on the retina, and finally washes away from the conjunctival sac and cornea remains of dead cells and bacteria.

Mucus layer

Mucus layer has a large swelling capacity, significantly reduces the surface tension and hydrophobic properties of the epithelium are so changes to hydrophilic. This allows for easy spreading water on the surface layer of the cornea and moisturized.

An imbalance in the quality and quantity of individual components of the tear film and blinking disorders worsen the distribution of tears and can pose a significant problem - such as dry eye syndrome.