Tears lubricate the eye and stop the surface from drying out. A thin film of tears is swept over the eye surface every time you blink. A watery layer of tears is topped with an even thinner coat of lipids (fatty compounds) that help to preserve the film. To maintain eye comfort and health, the tear film needs to remain intact between blinks.
A person suffering from dry eye syndrome does not have enough of the right kind of tears to keep the eye comfortable. This can happen if they do not produce enough tears to keep the eye surface moist, or if for some reason the tears do not stay on the eyes long enough. Over time, the resulting dryness can damage the surface of the eyeball.
Dry eye can afflict anyone of any age, but is more common as we get older because we produce a smaller volume of tears. Some medications can trigger dry eye, as can some general health conditions. Dry eye is particularly common in postmenopausal women and people with arthritis.
People with dry eyes typically find it difficult to wear contact lenses. Dry eye sufferers may also have more problems in environments such as air-conditioned offices or supermarkets.
There is no cure for dry eye, but its symptoms can be alleviated.