Allergic conjunctivitis: causes, symptoms, home care and treatment
Dr. Swati Goyal · 18 February 2025 · 7 min
A transparent membrane covers the eye, called the conjunctiva. When something triggers an allergy, it becomes swollen and red — and that is allergic conjunctivitis.
It is very common — on the figure cited in the video, it has been found in around 40 per cent of the population.
It comes in two patterns
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Acute or seasonal — it starts suddenly, usually as the weather turns.
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Perennial or chronic — it stays through the year.
What is actually happening
Just as bacteria or viruses provoke the body, the immune system can mistake ordinary everyday things for an enemy and mount a response against them. In the process a chemical called histamine is released, and it is histamine that produces the redness, watering, itching and swelling.
What triggers it
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Dust, strong wind, and air-conditioned air.
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Cobwebs, and damp or mould in the house.
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Pet hair, and carpets that hold dust.
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Smoke of any kind, pollution, and factory dust if there is one nearby.
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Pollen from particular plants and flowers when the season changes, carried on the air into the eye.
It usually travels with a cough, a runny nose or a cold — sneezing too.
What helps at home
First and most important — do not rub the eye. It feels better for a moment, but it increases the swelling and the redness. And do not keep splashing water into the eye, which worsens both the dryness and the allergy.
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A cold compress: soak a towel in cold water, wring it out, and rest it on the closed eye. The swelling settles and the eye stays moist.
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Cucumber: chill it, cut thin slices, and place them on the closed eye. It eases the swelling, the itching and the watering.
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Work out what you are allergic to, and stay away from it. Keep the house clean, and a humidifier can help.
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Wear a helmet and glasses when you go out or ride, so that dust and wind do not hit the eye head-on.
What the doctor will prescribe
If the itching, burning, redness and watering carry on despite all these precautions, see an eye specialist. They will prescribe lubricating drops, which keep the eye moist and flush out the by-products of the allergy, along with anti-allergic drops to blunt the effect of the histamine — these come in both steroid and non-steroid forms.
A related form: allergic blepharitis
Just as dandruff forms in the hair of the scalp, a similar scaly material can collect along the eyelashes and set off an allergy in the eye. This needs treatment from an eye specialist.
If your eye shows this kind of redness, itching, watering or swelling, do not ignore it.