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Why are my eyes dry? The common causes of dry eye

Dry eye is one of the most common eye problems, from teenagers to grandparents. It is rarely caused by one thing. Usually two or three causes add up: an air-conditioned office, long screen hours and some blockage of the eyelid oil glands, for example. This guide explains the common causes, so that you can see which apply to you, and when dryness needs an eye doctor.

How do tears keep the eye wet?

Every blink spreads a thin tear film over the eye. It has a watery layer from the tear glands, a mucus layer that helps it cling to the eye, and an oily outer layer from tiny glands along the edges of the eyelids (meibomian glands) that slows evaporation. Dry eye happens when the eye makes too little watery tear or, more often, when the tears evaporate too fast because the oily layer is poor or the blinks are too few. Many people have a mix of both.

Screens and concentration

People blink far less often while reading, driving or working on a screen, and many blinks do not close the eye fully. The tear film breaks up between blinks and the surface dries, which is why dryness is often worst at the end of a working day. See computer vision syndrome symptoms.

Air-conditioning, fans and wind

Moving, dry air speeds up evaporation. Air-conditioned offices, cars and buses, a ceiling fan running all night, and wind on a scooter or a ferry crossing all dry the eyes. Goa's dry, dusty months before the monsoon, and smoke from burning leaves and rubbish, add to the irritation.

Blocked eyelid oil glands and blepharitis

Meibomian gland dysfunction, where the oil glands in the lids become blocked or make thick oil, is one of the most common causes of dry eye. It often goes with blepharitis: inflamed lid edges, crusts at the base of the lashes, and eyes that are worse in the morning. Rosacea, a skin condition with redness of the face, often affects these glands too. Warm compresses and lid cleaning are the main treatment.

Age and hormones

Tear production falls with age, so dry eye becomes more common after 50. Women are affected more often than men, especially after menopause, when hormone changes affect the tear and oil glands.

Contact lenses

A contact lens sits in the tear film and splits it, so lenses can feel dry, especially late in the day, in air-conditioning, and when the lenses are old or poorly fitted. Long-term lens wear can also affect the eyelid oil glands. A different lens type or a shorter wearing time can help; see contact lenses: fitting and safe use.

Medicines

Several common kinds of medicine can reduce tears, including some antihistamines for allergy and colds, some medicines for blood pressure, some antidepressants and medicines for anxiety, some acne treatments taken by mouth, and some medicines for bladder problems. Long-term use of eye drops that contain preservatives, such as some glaucoma drops, can also irritate the surface of the eye. Do not stop any medicine on your own; ask the doctor who prescribed it whether there is an alternative.

Health conditions

• Diabetes, which is common in Goa, can reduce the feeling in the cornea and the quality of the tear film.
• Thyroid eye disease can make the eyes stare and stop the lids closing fully.
• Rheumatoid arthritis, lupus and Sjögren's syndrome, conditions in which the immune system attacks the body's own tissues, can damage the tear glands. Sjögren's also causes a dry mouth.
• Parkinson's disease and other conditions that reduce blinking.
• Eyelids that do not close fully, after a facial palsy (Bell's palsy) or because of the shape of the lids, leave part of the eye exposed, often during sleep.
• Vitamin A deficiency, now uncommon, can cause severe dry eye in children and needs medical treatment.

After eye surgery

Dryness is common for some weeks or months after cataract surgery, LASIK and other eye operations, while the nerves of the cornea and the tear film recover. If you already had dry eye before surgery, tell the eye doctor, so that it can be treated first.

Why do dry eyes water?

It seems odd, but watering is a common sign of dry eye. When the surface dries, it signals the tear glands to pour out reflex tears. These are mostly water, without the oil and mucus that keep a tear film stable, so they simply run down the cheek. Treating the dryness often stops the watering. Watering can also come from a blocked tear duct, which needs different treatment, so the eye doctor checks for both.

Can I tell what is causing my dry eye?

Ask yourself:

• Is it worse after screen work, in air-conditioning or on the scooter? (habits and surroundings)
• Are the lid edges red or crusty, and the eyes worse in the morning? (oil glands, blepharitis)
• Did it start after a new medicine? (medicine)
• Do you also have a dry mouth, joint pains or a thyroid problem? (a general condition)
• Does it come with itching? (allergy may be part of it; see itchy eyes: allergy or infection?)

Only an eye examination can tell for certain.

When should I see an eye doctor?

See an eye doctor if dryness lasts more than a couple of weeks despite simple steps, if you need lubricating drops many times a day, if your vision keeps blurring, or if you also have a dry mouth or joint pains. Come in the same day for pain, strong discomfort in bright light, a sudden drop in vision, or a red eye while wearing contact lenses.

The causes of your dry eye decide its treatment. How dry eye is checked and treated at ReNew Vision is explained on dry eye and screen strain treatment. The Eye OPD at ReNew Vision Eye Hospital in Vaddem, Vasco is open Monday to Saturday, 4 pm to 7 pm; call or WhatsApp 072489 88039.

Questions patients ask

Why are my eyes dry in an air-conditioned office?

Air-conditioning dries the air and moves it across the eye, so tears evaporate faster, and screen work at the same time cuts down blinking. Point vents away from your face, take regular breaks, blink fully, and see an eye doctor if the dryness continues.

Why do my eyes water if they are dry?

A dry eye surface triggers reflex tears, which are watery and run out instead of coating the eye. Treating the dryness often reduces the watering. Watering can also come from a blocked tear duct, so watering that does not stop should be checked.

Can medicines cause dry eyes?

Yes. Some antihistamines, some blood pressure medicines, some antidepressants and some acne treatments taken by mouth can reduce tears. Do not stop a medicine yourself; ask the doctor who prescribed it whether another one would suit you.

Is dry eye more common in women?

Yes. Dry eye is more common in women, especially after menopause, because hormone changes affect the tear and oil glands. It also becomes more common in everyone with age.

Can dry eyes be a sign of another illness?

Sometimes. Dry eyes with a dry mouth or joint pains can be a sign of Sjögren's syndrome or rheumatoid arthritis, and staring eyes may point to thyroid eye disease. Diabetes also affects the surface of the eye. The eye doctor will tell you if a general check-up is needed.

This page is general eye-health information, not personal medical advice. Your eye doctor advises you after examining your eyes.