Tingling, irritation, a feeling of sand in the eyes... Dry eye is characterised by a reduction in the quantity or quality of tears. Also known as dry eye syndrome, this ophthalmological condition can have multiple origins, and requires appropriate treatment to avoid complications.
What is dry eye?
To understand dry eyes, it is important to remember the essential role played by tears. Made up of water and fatty substances, tears are essential to protect the ocular structures from external aggression (wind, cold, pollution, etc.). Secreted by the lacrimal glands, tears are then distributed by the blinking of the eyelids over the surface of the eye. In the case of dry eyes, this physiological process malfunctions. The quantity or quality of the tears is no longer sufficient to perform this task properly.
What are the symptoms of dry eye?
Dry eye syndrome will manifest itself in different ways:
- stinging, itching, eye irritation
- difficulty opening the eyes in the morning, eyelids stuck together
- feeling of sand grains in the eyes
- burning sensation
- light hypersensitivity
- excessive tearing
- eye strain
- increased blinking frequency...
Causes of dry eye
In order to identify the cause of dry eye syndrome, the ophthalmologist must determine where the tear film is affected. The tear film consists of three layers:
- The lipid layer: secreted by the Meibomius glands, it serves to lubricate and prevent the evaporation of tears.
- The aqueous layer: produced by the lacrimal glands, it nourishes and protects the cornea
- The mucinic layer: manufactured by the mucoid glands, this layer allows the lacrimal film to be attached to the cornea.
Each of these layers can be involved in dry eye syndrome. A distinction is made between aqueous dryness, evaporative dryness and mixed dryness.
Who are the people at risk?
Of the 4 million French people suffering from dry eyes, only a minority suffer from aqueous dryness due to insufficient tears. The vast majority of those affected would suffer from pure or mixed evaporative dryness (36% 2) caused by a dysfunction of the Meibomius glands. Located in the upper and lower eyelids, there are between 50 and 70 Meibomian glands per eye. If they are obstructed, their secretion becomes insufficient, leading to a reduction in the thickness of the lipid layer, a reduction in the thickness of the aqueous layer and, ultimately, the drying out of the eye.
How can dry eyes be prevented?
To prevent the onset of dry eyes, there are a few precautions to take:
- avoid rubbing your eyes or eyelids
- do not expose yourself to tobacco smoke
- avoid air conditioning
- humidify and air out as much as possible your home and office
- protect your eyes from the wind by wearing sunglasses
- limit the amount of time spent in front of a computer screen or, if necessary, take regular breaks
- consult the side effects of medicines...