Tears eyes: types, structure and usefulness

A happy ending to a story, a sad breakup, an onion chopped into pieces – all these events can trigger your tears. Tears serve many purposes, and your eyes produce them all the time. In fact, you make 70 to 140 liters every year. Its presence is essential for the proper functioning of our eyes, and its absence generates extremely unpleasant problems for those who suffer from it, the best known and most widespread being dry eye, the solution of which is to use artificial tears.

There are several types of tear

Tears are essential to help us see clearly and maintain good eye health and to help us communicate our emotions. Our body produces three types:

The basal tears they are in our eyes permanently to lubricate, nourish and protect the cornea. Basal tears act as a shield between the eye and the rest of the world, preventing dirt and debris that float in the environment from coming into contact with our cornea.

The reflex tears They are formed when the eyes need to eliminate irritating and eventually harmful elements, such as smoke, foreign bodies or onion fumes. Our eyes release them in greater amounts than basal tears, and can contain a greater number of antibodies to help fight bacteria.

The emotional tears They occur in response to joy, sadness, fear, and other emotional states. Some scientists suggest that emotional tears contain additional hormones and proteins that are not present in basal or reflex tears.

Tears have a complex structure

The tear does not have only a saline composition. If not it has a structure similar to saliva and contains enzymes, lipids, metabolites and electrolytes. Tears have three layers:

• A inner layer of mucus that keeps all the tears attached to the eye.
• A middle layer aqueous (the thickest layer) to keep the eye hydrated, repel bacteria and protect the cornea.
• A oily layer external that has two functions, the first is to keep the surface of the tear smooth so that the eye can see through it and the second, to prevent the other layers from evaporating.

How the body produces tears

The lacrimal glands in each of our eyes are responsible for producing tears. When you blink, the tears spread over the ocular surface, to later be drained when their quantity is excessive through small holes located at the corners of the upper and lower eyelids. Once the excess tears have been eliminated, they travel through small channels in the eyelids and down a tube to end up evacuating through the nose. There, they will either evaporate or be reabsorbed.

Sometimes babies are born with a blocked tear duct, a condition that usually resolves on its own. An eye infection, swelling, injury, or tumor can cause a blocked tear duct in adults.

When many emotional or reflex tears occur, they overwhelm the tear drainage system. This is why these tears can spill down your eyes, run down your cheeks, and sometimes drip down your nose.

The amount of tears decreases with age

Basal tear production decreases with age, and this can lead to the development of dry eye. Dry eye is a common problem for people experiencing hormonal changes, especially women during pregnancy and menopause. Contact lenses and certain medications can also cause dry eyes.

If you have dry eye, you may also be prone to blepharitis, a common cause of eyelid irritation or swelling.

Buy single dose artificial tears with hyaluronic acid

More information: Blepharitis, what it is, symptoms and treatment

More information: All information about dry eye and its treatment

Source: Facts About Tears