When should you see a doctor about red eye?

Redness occurs when small blood vessels on the eye surface become more visible. Allergic conjunctivitis commonly brings itching and watering, while conjunctivitis may cause irritation and sticky discharge. Dry eye can feel gritty or burning, especially after screen use or in air conditioning. A stye may cause a tender bump at the eyelid edge. A foreign body in the eye can produce sudden watering, discomfort, or the feeling that something is trapped.

Wash your hands, avoid rubbing the eye, and remove contact lenses until the eye has recovered or a clinician advises otherwise. Use clean water to rinse away loose irritants, but do not try to scrape out an object stuck on the eye. Avoid sharing towels, pillows, or eye cosmetics when discharge suggests infection. A pharmacist or clinician can advise on suitable drops after considering the cause.

Seek urgent eye care for sudden vision change or loss, severe pain, marked light sensitivity, a chemical splash, an object that will not rinse out, or redness after an eye injury. Urgent assessment is also needed with severe headache, nausea, a fixed or unusual-looking pupil, or swelling that affects eye movement. Contact-lens wearers should seek prompt advice for a painful red eye because corneal infection can worsen quickly.

Ask whether the redness fits dry eye, allergy, conjunctivitis, a stye, or a foreign body, and whether the cornea needs checking. Ask how to use any drops, when you can resume contact lenses, and which changes mean you should return urgently.