Your tears function to protect the eyes and keep them lubricated and comfortable. Dry Eye Syndrome (DES) is the decline of the quantity and/or quality of the tears produced. It is caused when the tear glands in the upper and lower eyelids do not produce enough tears, or they don't produce the right kind of tears. This phenomenon causes the eyes to feel irritated, scratchy, burning, red, and uncomfortable. Dry Eye Syndrome is the most common of all eye disorders, affecting approximately 20% of our population.
Your eyes are moistened by two different types of tears: lubricating tears and reflex tears. Lubricating tears are produced continuously to moisturize the eye and contain natural infection-fighting antibiotics. Reflex tears are produced in response to sudden irritation (smoke, onions, foreign particles), injury, or emotion. Ironically, the irritation from dry eyes can trigger reflex tears, which flood the eye. But because reflex tears do not have the proper lubricating composition, the discomfort persists. Thus, "watery eyes" can actually be a symptom of Dry Eye Syndrome.