India's monsoon eye-flu surge

When the rains arrive, so does the redness. India sees a sharp, predictable rise in infective conjunctivitis every monsoon — humidity, waterlogging, crowding and shared water all help the adenovirus jump from eye to eye.

The 2023 monsoon outbreak was one of the largest in recent memory: government hospitals across Delhi, Maharashtra, Gujarat, West Bengal and the southern states reported a steep spike, with major Delhi hospitals alone recording tens of thousands of cases and several states issuing public advisories. Schools sent children home; offices saw rows of red, watering eyes behind dark glasses.

The Indian nickname tells the story. In the south it is "Madras eye"; across the north it is simply "eye flu" — because, like influenza, it is viral, highly contagious, and self-limiting. And like the flu, the worst mistake is treating it with the wrong medicine.

The conjunctiva: the membrane doing the suffering

The conjunctiva is a thin, transparent mucous membrane that lines the inner surface of your eyelids (the palpebral conjunctiva) and folds back to cover the white of the eye (the bulbar conjunctiva). It does not cover the cornea — the clear central window — which is why true conjunctivitis usually leaves vision intact.

Packed into this membrane are tiny blood vessels and immune cells. When a virus, bacterium or allergen irritates it, those vessels dilate and leak — and the white of the eye floods pink-red. Goblet cells and accessory tear glands ramp up secretion, producing the discharge that defines each type.

Viral, bacterial or allergic? Read your own eye

Three different problems hide behind the same red eye. Tell them apart and you already know most of the treatment. Tap each type:

Adenovirus: the engine behind "Madras eye"

Most epidemic eye flu is caused by adenovirus, a tough, non-enveloped virus that survives on doorknobs, taps, towels and phone screens for days. That durability — not unusual contagiousness of the eye itself — is why a single case in a household or classroom can become ten.

Two adenoviral patterns matter clinically. Pharyngoconjunctival fever pairs red eyes with fever and sore throat, common in children around contaminated swimming pools and shared water. Epidemic keratoconjunctivitis (EKC) is more severe: it can spread to the cornea, leaving small inflammatory deposits (subepithelial infiltrates) that blur vision and cause glare for weeks or months after the redness fades.

Bacterial conjunctivitis: when antibiotics earn their place

When discharge is thick, coloured and re-forms within minutes of wiping, bacterial infection is likely — and this is where antibiotic drops genuinely change the course. A broad-spectrum fluoroquinolone such as moxifloxacin covers the usual Gram-positive and Gram-negative culprits and typically produces visible improvement within 2–3 days.

The same molecule has a second, critical role in Indian cataract surgery: intracameral moxifloxacin injected into the eye at the end of surgery is one of the most effective measures against endophthalmitis, the feared post-operative infection. That overlap — surface infection control and surgical prophylaxis — is why moxifloxacin sits at the centre of the ophthalmic anti-infective shelf.

How eye flu spreads — and how to stop it

Adenoviral conjunctivitis spreads by contact, not by air: a rubbed eye, an unwashed hand, a shared towel, a common pillow, a passed-around phone. It does not spread by "looking at" an infected person — a myth that fuels needless panic every monsoon.

• Wash hands often with soap, especially after touching your eyes or face.
• Never share towels, pillows, handkerchiefs, eye drops, kajal or make-up.
• Stay home while the eye is red and watering — typically the first week.
• Stop contact lenses entirely until fully recovered; discard the current pair and case.
• Disinfect shared surfaces — taps, switches, phones, door handles.
• Dark glasses for comfort and to discourage rubbing — not because light "spreads" it.

When pink eye is not just pink eye

Simple conjunctivitis is uncomfortable but harmless. The danger is mistaking something sight-threatening for "just eye flu." Treat the following as reasons to see an ophthalmologist the same day:

At the slit lamp, a drop of fluorescein dye is the decisive test: under cobalt-blue light it stains any break in the corneal surface, instantly revealing an ulcer or the branching pattern of herpes. It is the single quickest way to separate a harmless red eye from a sight-threatening one.

Treatment & recovery timeline

For viral eye flu there is no drug that shortens the infection — the body clears it. Care is about comfort and not spreading it: cool compresses, frequent preservative-free lubricating drops, gentle cleaning of crusts with cooled boiled water, and rest. Expect peak symptoms around days 3–5 and gradual settling over 1–2 weeks.

For bacterial eye flu, antibiotic drops as prescribed usually bring improvement within 2–3 days; finish the full course. For allergic conjunctivitis, antihistamine drops and allergen avoidance are key, and it is not contagious. Across all types: do not rub, do not wear contact lenses or eye make-up until clear, and never reuse old or shared drops.

Five questions to ask your ophthalmologist

1. Is my conjunctivitis viral, bacterial or allergic — and how can you tell?
2. Do I actually need antibiotic drops, or will this clear on its own?
3. Has the infection reached my cornea? Should we do a fluorescein stain?
4. How long will I be contagious, and when can I return to work or school?
5. When should I come back urgently — what symptoms mean it is getting worse?

Agaaz Ophthalmics in the conjunctivitis pathway

Agaaz Ophthalmics manufactures the diagnostic and anti-infective tools clinicians reach for when a red eye walks into the clinic — the same products used in operating theatres across 15+ countries.

Product information is for clinical and educational reference. Medicines such as moxifloxacin and diagnostic dyes are used under the direction of a qualified eye-care professional. This article is general health education and not a substitute for examination, diagnosis or treatment by an ophthalmologist.

Eye flu: quick answers