"Red eye" describes any condition where the white of the eye looks pink or red due to irritated blood vessels. Conjunctivitis ("pink eye") — inflammation of the thin membrane over the white of the eye and inner eyelids — is one of the most common causes, from a virus, bacteria, or an allergic reaction. Telling these apart matters because treatment differs.
Symptoms
- Redness in one or both eyes
- Gritty or irritated feeling
- Eyelid swelling
- Viral: watery discharge, often spreads eye-to-eye, may come with a cold
- Bacterial: thick sticky yellow/white/green discharge, eyelids stuck on waking
- Allergic: intense itching, watery discharge, both eyes, often with sneezing
Causes & risk factors
- Viruses (most common, highly contagious)
- Bacteria (spreads via contact, contaminated hands/towels)
- Allergens — pollen, dust, animal dander, smoke, chlorine (not contagious)
- Contact lens wear with poor hygiene
- Close-contact settings (schools, hostels)
Diagnosis
- Examination of the eye and eyelids, including discharge pattern
- Slit-lamp examination in some cases
- Swab testing if the cause is unclear or severe/recurring
Treatment options
- Viral: usually resolves in 1–2 weeks; cool compresses, artificial tears; no antibiotics needed
- Bacterial: antibiotic drops/ointment, full prescribed course
- Allergic: antihistamine/anti-allergy drops, avoiding the trigger
- Avoid touching/rubbing eyes; stop contact lenses until clear
When to seek urgent care
Seek prompt attention for significant eye pain, light sensitivity, blurred vision that doesn't clear, a foreign-body feeling that persists, or symptoms after an eye injury or in a newborn.
Frequently asked questions
How long is conjunctivitis contagious?
Viral/bacterial forms are contagious while discharge and redness are active — typically several days to two weeks for viral, about 24 hours after starting antibiotics for bacterial. Allergic conjunctivitis is never contagious.
Should I stay home from work or school?
It's sensible to avoid close contact while symptoms are active, particularly for children, until discharge and redness settle.
Can I reuse old antibiotic drops from a previous infection?
No — the cause may differ this time, and old drops can be contaminated or ineffective.
Ready to see us?
Call the appointment desk, or book online — we will confirm your time by phone.
Sources consulted: AAO — Conjunctivitis (Pink Eye), CDC — About Pink Eye . General medical information — not a substitute for professional diagnosis. Content pending final medical review by BSEH doctors before publish.
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