Some people do not produce enough tears to keep the eye wet and comfortable. Stinging, burning, scratchiness, stringy mucus, and excess irritation from smoke are the usual symptoms. Dry eyes can make it difficult or impossible to wear contact lenses.

Surprisingly, increased tearing may be a symptom of dry eyes. If the basic tear secretion is below normal, excess tears are produced by the lacrimal gland in response to irritation. Even though the eye is basically dry, overflow tearing can occur, masking the dryness which caused the tears in the first place.

Tears run from our eyes when we cry or when our eyes are irritated. But tears have a much more important everyday function. A film of tears, spread over the eye by a blink, makes the surface of the eye smooth and optically clear. Without our tear film, good vision would not be possible.

The tear film consists of three layers: an oily layer, a watery layer, and a layer of mucus.

The outer oily layer of the tear film is produced by small glands at the edge of the eyelid, called meibomian glands. The main purpose of this oily layer is to smooth the tear surface and reduce evaporation of tears.

The middle water layer, the largest of the three layers, makes up most of what we ordinarily think of as tears. This watery layer is produced by small glands scattered through the conjunctiva, the delicate membrane lining the inside of the eyelid and covering the eyeball, and by the major tear gland, the large lacrimal gland. This layer cleanses the eye and washes away foreign particles or irritants.

The innermost layer consists of mucus produced by other cells in the conjunctiva. This layer allows the watery layer to spread evenly over the surface of the eye and helps the eye to remain wet. Without mucus, tears would not adhere to the eye.

There are two kinds of tears, those which lubricate the eye and those which are produced as a response to irritation or emotion.

Tears which lubricate the eye are produced around the clock. Excessive tears occur when the eye is irritated by a foreign body or when a person cries.

Tear production usually decreases with age. Although dry eyes can occur in both men and women at any age, women, especially after menopause, are most often afflicted.

Dry eyes can also be associated with arthritis and accompanied by a dry mouth. People with dry eyes, dry mouth, and arthritis are said to have Sjogrens syndrome.

Drugs and medications can also cause dry eyes by reducing tear secretion. Since these medications are often necessary, the dry eye condition may have to be tolerated or treated with "artificial tears."

Often an ophthalmologist is able to diagnose dry eyes by simply examining the eyes. Sometimes tests which measure tear production may be necessary. One widely used test, the Schirmer tear test, involves placing filter-paper strips under the lower eyelids to measure the rate of tear production under various conditions.

Replacing natural tears with artificial tears is the basis of treatment. Artificial tears are available without a prescription and are used as eyedrops to lubricate the eyes and replace the missing moisture. There are many brands of artificial tears on the market, and many people try several different brands to find one which suits them best. The tears may be used as often as necessary, only once or twice a day, or as often as several times an hour. Solid inserts that gradually release lubricants during the day are also beneficial to some people.

Conserving the naturally produced tears is another approach to keeping the eyes moist. After bathing the eye’s surface, tears enter a small opening in each lid, the punctum and drain through a small canal, the canaliculus, into the lacrimal sac and down the naso-lacrimal duct into the nose These channels may be closed temporarily, or permanently, by your ophthalmologist. The closure creates a reservoir of tears which allows the eyes to stay moist for longer periods of time.

Preventing the evaporation of tears can also prove helpful, in winter, when the heat is turned on, a humidifier or a pan of water on the radiator adds moisture to dry air. Wrap-around glasses (illegal to wear while driving ) may cut down evaporation of eye moisture due to wind.

Anything that adds to dryness such as an overly warm room, hair dryers, windy days, or anything that adds an irritant to the air will make a person with dry eyes more uncomfortable. Smoking is especially bothersome.

Scratchy eyes upon awakening. This symptom can be treated by using an ointment at bedtime. Use the smallest amount of ointment necessary for comfort, since the ointment can cause temporary blurring of vision.

Although ointments containing vitamin A seem to be of some benefit to people with severe dry eye due to scarring from Steven-Johnson syndrome or Pemphigoid, vitamin A does not seem to help people with ordinary dry eye.

A person suffering from dry eyes may only need over-the-counter artificial tears, but since extreme dryness can cause serious damage to the eye, an examination and diagnosis by your ophthalmologist is suggested.