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Itchy, watery eyes: is it an allergy or an infection?

Red, itchy, watery eyes are one of the most common reasons people reach for eye drops. The cause is usually either an allergy or an infection, and the two need different care. This guide helps you tell them apart, explains what you can safely do at home, and lists the signs that mean something else is going on.

How can I tell allergy from infection?

Signs that point to eye allergy

• itching, often strong: the hallmark of allergy
• both eyes affected at the same time
• clear, watery tears, sometimes with white, stringy mucus
• puffy eyelids
• sneezing, a runny or blocked nose, or asthma at the same time
• a pattern: worse in certain seasons or places, or after dust, cleaning or contact with pets
• allergy, asthma or eczema in you or your family

Signs that point to infection

• a gritty, sandy or burning feeling more than itching
• thick yellow or green discharge, and lids stuck together in the morning (more likely bacterial)
• a red, watery eye after a cold or sore throat, sometimes with a tender lump just in front of the ear (more likely viral)
• often one eye first, then the other
• others at home, school or work with the same thing

The signs overlap, and both can happen at once, for example when rubbing an itchy eye brings in an infection. Read more about infection in eye flu (conjunctivitis): what to do.

What else can cause itchy or watery eyes?

• Dry eye: burning, grittiness and, oddly, watering, often worse with screens and air-conditioning. See what causes dry eyes.
• Blepharitis: itchy, red, crusty lid edges, worse in the morning.
• Reactions to products: kajal, eye make-up, face creams, hair dye, or a new eye drop.
• Contact lens problems: deposits on a lens or a reaction to the solution can cause itching and mucus.

What triggers eye allergy in Goa?

• dust from roads and building work, especially in the dry months before the monsoon
• pollen from grasses, trees and flowering plants
• mould, which grows in homes in the damp monsoon months
• house dust mites in bedding, mattresses and soft toys
• pet hair and dander
• smoke, incense, mosquito coils and strong perfumes, which irritate allergic eyes further

Spring catarrh in children

Some children, more often boys and especially in warm climates, get a more severe, long-lasting eye allergy called spring catarrh or vernal keratoconjunctivitis. The eyes itch intensely, there is thick, ropy mucus, the child may find bright light uncomfortable, and they rub their eyes constantly. It tends to flare in the hot months and often settles by the late teens. It needs an eye doctor's care and regular follow-up, because it can affect the cornea, and constant rubbing can change the shape of the cornea over time.

What can I do at home for eye allergy?

• Do not rub. Rubbing releases more of the chemicals that cause itching, and makes it worse.
• Hold a cool, clean, damp cloth over the closed eyes for a few minutes.
• Rinse your face and eyelids with clean water after being outdoors in dust.
• Wear sunglasses or spectacles outdoors, and use a helmet visor on the scooter, to keep dust and pollen out.
• Wash pillow covers and bedsheets every week in hot water, keep pets out of the bedroom, and deal with damp and mould at home.
• Keep windows closed on dusty, windy days.
• Lubricating drops (artificial tears) can soothe the eye and wash allergens away.
• Stop using any new eye make-up, kajal or cream that may have started it.

What treatment does an eye doctor give?

For eye allergy, the eye doctor may advise anti-allergy eye drops that block the itch (antihistamine drops) or that make the eye less reactive over time (mast-cell stabiliser drops); some drops do both. For severe allergy, such as spring catarrh, stronger anti-inflammatory drops may be needed for short periods under close supervision, because some of them can raise eye pressure or cause cataract if they are overused. For infection, treatment depends on whether it is likely to be viral or bacterial.

Do not buy steroid drops over the counter for itchy eyes. They may give quick relief, but used without check-ups they can cause glaucoma and cataract, and they can make some infections much worse.

When should I see an eye doctor?

• pain in the eye, rather than itching or grittiness
• blurred vision that does not clear with blinking
• pain in bright light
• one eye only, and very red
• a red eye in a contact lens wearer
• a child who rubs their eyes constantly or has thick, ropy mucus
• no improvement after a few days of home care, or symptoms that keep coming back

A red eye with pain, blurred vision or pain in bright light can be a corneal ulcer or inflammation inside the eye; see uveitis symptoms. Eye allergy and eye infections are treated at ReNew Vision Eye Hospital, Vaddem, Vasco, in the Eye OPD, Monday to Saturday, 4 pm to 7 pm, and emergency eye care is available 24 hours. Call or WhatsApp 072489 88039. Other red eye problems are covered on the red eye, dry eye and cornea page.

Questions patients ask

Is eye allergy contagious?

No. Eye allergy is the body's reaction to things like dust, pollen or pet hair, and it cannot pass from person to person. Viral and bacterial eye infections can spread, which is one reason it helps to know the difference.

Can eye allergy affect only one eye?

Allergy usually affects both eyes. One eye can react more if the allergen got into it, for example from a hand or a product. A red, painful eye on one side only should be seen by an eye doctor.

Why does my child keep rubbing their eyes?

Often it is allergy, tiredness or eye strain. Constant rubbing with intense itching and thick, ropy mucus may be spring catarrh, which needs an eye doctor. Rubbing makes allergy worse and can harm the cornea over time, so get it checked.

Can I use the same eye drops for allergy and infection?

No. Anti-allergy drops do not treat infection, and antibiotic drops do not help allergy or viral eye flu. Steroid drops can make some infections much worse. Use drops only as advised by an eye doctor.

Why are my eye allergies worse in the monsoon?

Damp homes in the monsoon grow mould, and house dust mites thrive in humid bedding. Both are common triggers of eye allergy. Airing rooms, drying clothes properly and washing bedding often can help.

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