Guide · urgent
Red eye: when it’s nothing, and when it’s today
Most red eyes settle on their own. A few are the kind that damage sight if left a week. The difference is four signs, and none of them is “how red”.
The four signs that mean today
Pain — not gritty, painful, especially if light hurts. Blurred vision that doesn’t clear with a blink. One eye only, after something went in it. A contact lens in a red eye. Any one of these: ring for a same-day appointment. If it’s a very painful eye with nausea and haloes round lights, go to A&E — that’s raised pressure, and it’s hours, not days.
The ones that can wait a day or two
Both eyes red and sticky in the morning, otherwise comfortable: conjunctivitis. Warm water on a clean cotton pad, don’t share towels, and book if it’s not better in three days. Itchy, red, with a runny nose: allergy. Cold compress, antihistamine drop from the pharmacy. A bright red patch on the white, no pain, normal vision: a burst vessel. Looks dreadful, harmless, gone in a fortnight. Red rims that come and go for months: blepharitis or dry eye — not urgent, but worth a Dry Eye Assessment.
Tonight, while you wait
Don’t rub. Don’t use “red-eye” whitening drops — they constrict the vessels and rebound worse. Take contact lenses out. A cold compress helps itch; a warm one helps a sticky lid. Don’t put in someone else’s old drops.
What we do
Twenty minutes: the front of the eye under the microscope, the pressure, the back of the eye if needed. Most red eyes leave with a prescription and a plan. If it’s hospital, we ring them from the room.
The short version
- Pain, blur, one eye after an injury, or a contact lens: same day
- Sticky both eyes, itchy with hay fever, a red patch with no pain: can wait
- No rubbing, no whitening drops, lenses out
- Ring; a person answers and tells you which it is