What are Dry Eyes?
Dry eyes are a very common eye problem. It becomes more common as we age. The glands that secrete tears diminish over time. The eye depends on a constant supply of lubrication to maintain the health of the cells on the surface of the eye and promote clear vision. There are three layers to the tear film. A mucous layer, a watery layer, and an oily layer (to help prevent the tears from evaporating from the eye) make up the normal tear film. Each layer is produced by different glands around the eye. The medical term for dry eyes is keratitis sicca. With the lack of proper tears on the surface of the eye, damage to the cells of the surface of the eye begins causing symptoms.
Dry Eye Symptoms
Dry sensation, eyes sticking together
Foreign body sensation, feeling of something in the eye, or gritty sensation
Itching of the eye or around the edge of the eyelids
Blurred vision which tends to come and go. Blurred vision which begins after reading for a period of time is many times caused by dry eye. If there is not a normal smooth surface of a tear film present, then the light entering the eye will be reflected and not focused into the eye on to the retina. This blurred vision can begin even within a minute or two depending on the severity of the dry eye condition. Just like the windshield of a car if there are raindrops on the windshield, your ability to see out is diminished.
Redness due to the eye being irritated and not protected by the nourishing effects of a normal tear film is very common.
How can People with Dry Eyes Complain of Watery Eyes?
Many people complain of their eyes burning and watering. This at first sounds confusing but the watering is the result of the eye irritation. Once the cells of the sense that the loss of tears is causing damage, a signal is to the lacrimal gland to send more tears. Unfortunately, these tears do not have the regular nutrients and other components that comprise the normal tear film. Many people complain of their symptoms being worse first thing in the morning or late in the evening.