Dry eye occurs when our body does not produce enough quality tears to lubricate our eyes. Dry eye can cause irritated, gritty, red, painful, watery, and light sensitive eyes.
We need healthy, robust tears to protect the front surface of our eyes (the cornea). When dirt, debri, bacteria, or allergens get into our eyes, our tears help wash it all away, without incident.
Tears are also necessary to hydrate and smooth our corneas, in order to provide a smooth and clear primary surface for our optimal vision. Just like our skin, when our corneas get dry, areas or small pieces can slough off causing mild to severe fluxuations or distortions to our vision.
Blinking helps to secrete new tears onto our corneas, as well as swiping up old tears that are pooling down around our lower lids. Blinking also helps drain excess tears, down through small drainage ducts at the inner corners of our eyes. (From there tears drain through our nose, and then down the back of our throat. That is why we can “taste” our tears or eye drops.)
Dry eye is a common condition. Often, it is a chronic condition, caused by insufficient tear production. Tears are not just “water”, they are also composed of oil, mucus, and several other components. The water component hydrates the corneas, the mucus keeps the water spread evenly across the corneas, and the oil keeps the water from evaporating too quickly. Each individual’s dry eye symptoms can be caused by deficiencies in any one, or a combination of these components.