What Is Dry Eye?

Did you know that your eyes blink every four to six seconds, and with every blink, they get hydrated with the tears they produce?

Normally, your eyes produce healthy tears at a slow and constant rate. Tears keep the surface of your eyes moist so you feel comfortable. For people with dry eyes, the surface of the eyes does not get the moisture it needs.

What Is Dry Eye?

Dry eye occurs when the eyes either don’t produce normal tears or when tears are evaporating too quickly. It can lead to a sandy or scratchy sensation, and burning, itching or stinging eyes, among other symptoms.

Did you know? 1/3 of the Canadian adult population claims they have dry eyes.

Tear Film and Dry Eyes

The tear film is the liquid that protects your cornea. It keeps your eyes hydrated and lubricated and protects your eyes from dryness. There are actually three separate layers to the tear film: the outer lipid (oily) layer, the middle aqueous (watery) layer and the inner mucin layer. Dry eye occurs when a tear film evaporates or breaks up too soon.


Problems with any of the three tear film layers can cause dry eyes, and if the tear film evaporates or breaks up too quickly, then your eyes may feel dry or scratchy.