Seventeen year-old Ria Chaddha and her 75-year-old grandmother, Priti Devi Chaddha, share the same eye problems and visit the same ophthalmologist. Both of them suffer from the little-known 'dry eye syndrome' which essentially means that their tear glands are drying up.

Little may be known about this syndrome but it is affecting a lot of people. According to doctors, one out of every five persons is afflicted with this syndrome, particularly those in the older age group. It is estimated that nearly 75 per cent of people aged over 65 experience a drying up of their tear glands. Women are more vulnerable because of hormonal changes during menopause, and drier skin than men.

Now doctors have identified another reason for people in cities getting a dry eye. Says Dr Satish Chandra Gupta, Medical Director of New Delhi's Venu Eye Institute: "The city's pollution and smoke is responsible for 80 per cent of the patients suffering from the dry eye syndrome in Delhi."

In the 'dry eye syndrome' the quality and quantity of tears generally falls from the normal level and a person experiences constant pain due to eye irritation and a sandy or gritty sensation. If this is not treated in time, it can lead to scarring or ulceration of the cornea and thus loss of vision.

But since few are aware of this problem, it is often neglected. For instance, Ria's grandmother found it difficult to shed tears even under extreme emotional distress. She ignored the problem, assuming that she had become emotionally stronger over the years. It was only when she had problems reading that she visited an ophthalmologist. "I never realized that my tear glands were drying up. It was only after I started having a burning sensation in my eyes that I went to see a doctor," she says.

The 'dry eye syndrome' is generally the result of disorders of the various glands that produce normal tears. Tears themselves are a complex combination of substances in three different layers in the eye. The very thin outer layer contains lipids in the eyelid, which reduce evaporation. The lacrimal glands produce the middle watery layer that maintains the saline and acid levels of the tears. This layer also carries antibodies and other immune defence agents to defend the eye against infections. The inner or mucous layer helps the tear film "stick" to the cornea. Any dysfunction of these three layers can cause a dry eye.

The other causes of the 'dry eye syndrome' include normal ageing of the tear glands and some diseases or disorders that change the amount and condition of tears. With age, our bodies also produce less oil. And this is more true in the case of women as they have drier skin than men. This reduction in oil also affects the tear film. Without much oil to seal the watery layer, the tear film evaporates much faster, leaving dry areas on the cornea.

"Sixty per cent of women above the age of 50 years who visit an ophthalmologist do so because they have a dry eye," says senior ophthalmologist Dr Atul Kumar Rohtagi.

A person can also have a dry eye because of irregularities in the cornea, resulting in uneven or inadequate tear coverage of the eye. It could also be a result of medications like antibiotics, anti-histamines, diuretics and anti-diarrhoeals, which dry up the mucous membranes. Hormonal changes can also affect secretions from the tear glands. "This is mostly seen in pregnant or menopausal women," explains ophthalmologist Dr Debarati Chatterjee.

People suffering from allergies and those wearing contact lenses are at a greater risk of developing a dry eye. Ria, for instance, is a typical case where one is affected by constant use of contact lenses. The contact lenses absorb the tear film, causing proteins to form on the surface of the lens. Doctors recommend not using lenses if one has a dry eye. And even otherwise they recommend using moisturizing solutions for those who use lenses to keep the eyes wet.

Early signs of the 'dry eye syndrome' include an occasional burning sensation in the eyes along with a persistent gritty sensation. At the same time, a person suffering from the 'dry eye syndrome' is unable to cry under emotional stress. And in extreme cases, a person can be unusually sensitive to light, experience severe pain in the eye or notice diminished vision.

The basic treatment for dry eyes involves applying artificial tears and ointments for temporary relief. Some of these products are watery and alleviate the symptoms temporarily; others are thicker and adhere to the eye longer. Closing the opening of the tear drain in the eyelid with special inserts called punctual plug-ins is another option. This works like closing a sink drain with a stopper. The special plugs trap the tears in the eye, keeping it moist. This may be done on a temporary basis with a dissolvable collagen plug, or permanently with a silicone plug.

There are other, easier solutions to the dry eye syndrome: drinking eight to ten glasses of water in a day can significantly improve irritation because the water keeps the body hydrated and flushes impurities. Blinking frequently while reading or watching television also helps.

But it is important to know the exact reason why one has got a dry eye. "If, for example, the reason is deficiency of Vitamin A, then one can take a diet rich in Vitamin A like carrots, pumpkin, green leafy vegetables and tomatoes," says Chatterjee. Sometimes lack of essential fatty acids in the body can also become the cause for a dry eye, in which case a change of diet may help.

However, doctors are unanimous about one thing: if one is affected by a dry eye then it is a must to avoid anti-depressants. Some other medicines are also contra-indicated - medical professionals can advise according to the case. Advises Gupta, "The affected person should avoid being in centrally heated and air conditioned places and also avoid dust, smoke or other allergens."

So the next time you have a tired and heavy or even itchy feeling in your eye lid while reading or watching television, or even feel lack of emotional tears, don't have the misconception that you are just tired or have grown stronger emotionally. You could well be suffering from the 'dry eye syndrome'. Take a trip to your ophthalmologist.