Dry eye syndrome is one of the most common problems treated by eye physicians. Over ten million Americans suffer from dry eyes. It is usually caused by a problem with the quality of the tear film that lubricates the eyes. Healthy eyes are continuously covered by a tear film ? a constant layer of fluid designed to remain stable between blinks. A stable tear film prevents dry eyes and allows your eyes to maintain clear, comfortable vision.

The tear film protects eyes and lubricates them. It also reduces the risk of eye infection and, each blink of eyelids, helps clear your eyes of any debris. Decreased production of fluids from tear glands can destabilize the tear film, allowing it to break down rapidly and create dry spots on the clear front surface of the eye (cornea) that cause irritation and diminished vision. An imbalance in the substances that make up the tear film also lead to dry eyes.

Dry eyes are a common source of discomfort, and usually dry eyes are a chronic problem. Adults age 40 or older are most likely to experience dry eyes. Treatment of dry eyes is aimed at restoring a more normal tear film to minimize dryness and its consequences, including blurred vision and discomfort.

Signs and symptoms of dry eyes:

A stinging, burning or scratchy sensation in your eyes.

A sense of a foreign substance in your eyes.

Stringy mucus in or around your eyes.

Increased eye irritation from smoke or wind.

Eye fatigue after short periods of reading.

Sensitivity to light.

Difficulty wearing contact lenses.

Blurred vision, often worsening at the end of the day or after visually focusing for a prolonged period on a nearby task.

Difficulty in opening eyes specially in the morning.

The tear film is composed of three layers from inside to outside- mucus, water and lipid layer. Any instability in any of the three layers can cause dry eyes. The various causes of dry eye can be ?

Decreased tear production. This is seen in old age and more I females after menopause (due to hormone imbalance).

Refractive eye surgeries and other eye procedures can cause a transient decrease in tear production, which returns to normal after a few months.

Inflammatory eye conditions like blepharitis, allergic conjunctivitis, poor blinking and closure of eyes.

Long work and sitting on computers, decreases the blink rate and causes dryness in the eyes.

Some medicines can cause dry eye like diuretics (for treatment of high blood pressure), antihistamines and decongestants, sleeping pills, birth control pills, tricyclic antidepressants, isotretinoin-type drugs for treatment of acne, opiate-based pain relievers such as morphine.

Meibomian gland disease ? The meibomian glands (secrete the outer lipid layer of the tear film) get blocked. This results in unstable tear film and dryness.

The diagnosis of dry eye is done by examination of the eye, measuring tear production (Schirmer's test) and other tests.

Treatment of dry eye:

First and foremost is to manage any lid abnormality if present to facilitae proper closure of eyes.

Tear substitute eye drops should be used. Best are the eye drops without any added preservative.

In severe dry eye, conservation of tears into the eyes can be done by blocking the hole in the eyelids through which the tears drain out.

In patients with meibomian gland disease, treatment is aimed at opening the gland openings with eye massage and oral medicines along with artificial eye drops.

In very severe cases, some patients are prescribed cyclosporine eye drops, decreases inflammation on the eye surface and helps increase production of healthy tears.

Self care to decrease symptoms of dry eye:

Don't direct hair dryers, car heaters, air conditioners or fans toward your eyes.

Wear glasses on windy days and goggles while swimming.

Keep your home humidity between 30 percent and 50 percent. In winter, a humidifier can add moisture to dry indoor air.

Avoid rubbing your eyes.

Use eye drops before, rather than after, your eyes become irritated as a result of visually demanding activities.

Consciously blinking repeatedly helps spread your own tears more evenly. When performing tasks that require intense visual concentration, take occasional breaks ? adding up to about five minutes each hour ? and rest your eyes by closing your lids for several seconds.