At anterior segment of the eye there is a thin liquid layer that covers the cornea and conjunctiva, this layer is known as the tear film.
This substance is extremely important for eye health, as it is responsible for moisturizing the eye and protecting it from external agents that may affect it.
En Área Oftalmológica Avanzada We explain below what the tear film is and why it is so important for the eyeball.
What is the tear film?
The tear film is a thin layer of fluid that covers the entire cornea and conjunctiva.
This layer is so thin that it is almost imperceptible to the eye, however, and thanks to medical and technological advances, today it is possible to examine and study the tear film to check its thickness and the condition of each of its layers.
Layers that make up the tear film
The tear film, despite being very thin, is made up of three layers:
- Oily or lipid layer: It is the superficial and outermost part of the tear film. This layer is responsible for delaying evaporation and keeping the eye moist, actions that allow smooth blinking.
- Aqueous layer: It is the middle layer of the tear film and also the thickest. It is composed of salts, proteins, glucose and electrolytes. The function of the aqueous layer is to offer oxygen to the cornea and clean it of external debris thanks to its content of antibacterial substances.
- mucin or mucin layer: it is the inner layer of the tear film and the one closest to the cornea. This structure is a kind of very thin sheet that must be kept lubricated in order to perform the functions of holding the tear film to the ocular surface, hydration and protection of the cornea.
Which functions has
Despite being very thin, the tear film performs very important functions for eye health, let's see:
- It offers the cornea the smooth and refractive surface necessary to view images clearly.
- It protects the cornea from external factors and keeps it hydrated and oxygenated.
- Thanks to its antibacterial property, it helps eliminate germs and bacteria that could cause an eye infection.
- It keeps the eye hydrated so that constant blinking is not annoying or painful.
Alterations of the tear film
Altering the tear film can cause very annoying damage to the ocular structure.
Let us know below what are the most common eye diseases related to the tear film:
dry eye syndrome
When the tear film is unstable or its quality is not good enough to keep the eyes hydrated, we know that we are facing a picture of eye dryness or dry eye.
This condition is chronic and usually causes photophobia, gritty sensation in the eye, burning, ocular pain and discomfort when blinking.
Functional or obstructive epiphora
It occurs when there is a failure in the lacrimal drainage system that causes continued excess tear secretion.
This condition is associated with various causes, therefore it is advisable to go to the ophthalmologist whenever symptoms of epiphora functional.
Dacryocystitis
It is the inflammation of the lacrimal sac that can usually be caused by the obstruction or infection of the lacrimal duct.
Polyps and trauma can also cause dacryocystitis.
En Área Oftalmológica Avanzada We are experts in eye health care, do not hesitate to contact us if you need to have a Ophthalmological examination complete with one of our professionals. We will wait for you!
