Viral conjunctivitis
Usually caused by adenovirus, often alongside or after a cold or sore throat. The eye is red and watery with a gritty feeling and mild swelling, and a tender lymph node may be felt in front of the ear. It often starts in one eye and spreads to the other within days. It is highly contagious through hands, towels and surfaces for as long as the eye is weeping. There is no antiviral treatment; cool compresses and lubricating drops relieve symptoms, and it resolves in one to three weeks. Some strains inflame the cornea, causing light sensitivity and blur that can last weeks and occasionally needs steroid drops under supervision.
Bacterial conjunctivitis
Thick yellow or green discharge, lids stuck together on waking, and a red eye, often in one eye first. More common in children. Antibiotic drops or ointment shorten it to a few days, and it is contagious until 24 hours after treatment starts. Wipe discharge with a clean tissue each time and wash hands. A discharge that is profuse and rapid in a newborn or after a new sexual contact needs urgent assessment for specific bacteria.
Allergic conjunctivitis
Itching is the defining symptom, with redness, watering and swelling in both eyes, often with sneezing and a runny nose, in pollen season or on exposure to animals or dust. It is not contagious. Antihistamine and mast cell stabilizer drops control it, cool compresses help, and avoiding the allergen and not rubbing the eyes reduce it. Severe forms in children and in contact lens wearers are managed by an eye doctor.
When it is not conjunctivitis
Real pain, light sensitivity, blurred vision, a white spot on the cornea, or redness concentrated around the cornea point to keratitis, iritis or acute glaucoma, none of which are conjunctivitis and all of which need same-day care. A contact lens wearer with a red eye is examined the same day regardless.
Stopping the spread
Wash hands often and after touching the eyes; do not share towels, pillows or makeup; discard eye makeup used during the infection; stop contact lenses and replace the lens and case afterward; and keep children home from school while the eye is weeping, per the school's policy.
Is this right for your eyes?
Nothing on this page is a diagnosis. Whether this is what is affecting your vision is decided by a full examination at one of our 4 offices: Pasadena, Huntington Beach, Woodland Hills and Beverly Hills.
About this content: This page was written with the assistance of AI tools and reviewed for medical accuracy by Dr. Bavand Youssefzadeh, DO. It is general information, not medical advice, and does not replace an eye examination. Individual results vary. Read our medical disclaimer.
