A red eye can look alarming, but many causes are harmless and settle on their own. The key is knowing which symptoms need urgent attention.
Common, usually mild causes
- Conjunctivitis. Redness with watering, stickiness or itching
- Dry eye and screen strain
- Allergy, usually itchy and in both eyes
- Subconjunctival haemorrhage, a painless bright red patch
- Blepharitis, with sore, crusty eyelids
Warning signs: seek same-day care
- Moderate or severe eye pain
- Reduced or blurred vision that does not clear with blinking
- Sensitivity to light
- Halos around lights, headache, nausea or vomiting
- A red eye after an injury or chemical splash
- A red, painful eye in a contact lens wearer
- A red eye after recent eye surgery
- A red eye in a newborn
These can signal a corneal infection, uveitis, acute glaucoma or an injury, all of which need prompt treatment.
Read more about conjunctivitis and corneal ulcers.
Frequently asked questions
Should I use redness-relief drops?
Occasional use is fine, but regular use can cause rebound redness. Find and treat the cause instead.
Can I wait a few days?
For mild redness without pain or vision change, yes. If warning signs appear, seek care the same day.
Sources
This article is for general information and does not replace an examination by an eye doctor. If you have symptoms, please book a consultation.