Dry eye syndrome is caused by a chronic lack of sufficient lubrication and moisture on the surface of the eye. Consequences of dry eyes range from subtle but constant eye irritation to significant inflammation and even scarring of the front surface of the eye.
Dry Eye Symptoms
Symptoms of dry eyes and dry eye syndrome include:
- Burning sensation
- Itchy Eyes
- Aching sensations
- Heavy eyes
- Fatigued eyes
- Sore eyes
- Dryness sensation
- Red eyes
- Light sensitivity
- Blurred vision
Another common symptom is something called a foreign body sensation — the feeling that grit or some other object or material is “in” your eye.
As odd as it may sound, watery eyes also can be a symptom of dry eye syndrome. This is because dryness on the eye’s surface sometimes will over-stimulate production of the watery component of your tears as a protective mechanism. But this “reflex tearing” does not stay on the eye long enough to correct the underlying dry eye condition.
In addition to these symptoms, dry eyes can cause inflammation and (sometimes permanent) damage to the surface of the eye.
What Causes Dry Eye Syndrome?
An adequate and consistent layer of tears on the surface of the eye is essential to keep your eyes healthy, comfortable and seeing well. Tears bathe the eye’s surface to keep it moist and wash away dust, debris and microorganisms that could damage the cornea and lead to an eye infection.
A normal tear film consists of three important components:
- An oily (lipid) component
- A watery (aqueous) component
- A mucous-like (mucin) component
Each component of the tear film serves a critical purpose. For example, tear lipids help keep the tear film from evaporating too quickly and increase lubrication, while mucin helps anchor and spread the tears across the surface of the eye.
Each tear component is produced by different glands on or near the eye:
- The oily component is produced by meibomian glands in the eyelids.
- The watery component is produced by lacrimal glands located behind the outer aspect of the upper eyelids.
- The mucin component is produced by goblet cells in the conjunctiva that covers the sclera (the white of the eye).
The specific type of dry eye often will determine the type of treatment your eye doctor recommends to give you relief from your dry eye symptoms.