What is meant by dry eyes?
When you blink a film of tears spreads over the eye, making the surface of the eye smooth and clear. Without this tear film, good vision would not be possible. The eye produces two types of tears. The eye makes tears at a slow and steady rate (basal tears) thus maintaining normal eye lubrication. It also produces tears in response to eye irritation or emotion (reflex tears). When the eye is irritated or when a person cries then excessive tearing occurs, these are reflex tears. When the eye becomes dry, the lack basal tears. The eye always have lots of reflex tears. Thus when there is a lack of the basal tears, the eyes start to feel gritty, or scratchy. Sometime the eye may even burn. The eyes feel this irritation and start tearing (reflex tears). It may not sound logical that a dry eye would cause excess tearing, but think of it as the eye’s response to discomfort.
The main reason for dry eye is a deficiency in the aqueous layer of the tear film. The surface of the eye loses the lubricating, protective, nourishing and cleansing action of the tear film, which leads to subclinical ocular damage; pain, light sensitivity, itching, redness, gritty sensations, etc. This may then be accompanied by reflex tearing, which is the eye’s response to the irritation or damage.
The causes of dry eyes are many, including: age, environmental conditions, certain medications, menopause and sometimes the continuous use of contact lenses. People who read for prolonged periods or work for long hours on a computer are also very proned to dry eyes syndrome.
Unfortunately there is no permanent cure for dry eyes. The most common solution is to use eye drops, called artificial tears, which are similar to your own basal tears. They lubricate the eyes and help maintain moisture. Thereby also switching of the reflex tearing. Artificial tears are available without a prescription, and there are different brands and viscosities available.