One Eye Red and Itchy: What to Know

Itching points toward irritation or an allergic reaction, especially with watering, puffy lids or exposure to dust, pollen, cosmetics or animal dander. Allergic conjunctivitis can begin on one side after local contact or rubbing. Conjunctivitis may cause redness and discharge and can spread between eyes. A foreign body, dry eye or eyelid inflammation can produce similar discomfort. Pain is less typical of uncomplicated allergy, so its presence changes how quickly the eye should be checked.

Wash your hands, avoid rubbing, and apply a cool clean compress to the closed eyelid. Rinse away obvious dust with clean water, but do not scrape the eye. Pause contact lenses and eye makeup until symptoms have resolved or a clinician has advised you. Do not share towels or cosmetics, and clean frequently touched surfaces if discharge is present. A pharmacist can discuss a suitable lubricating or allergy drop; avoid using another person’s prescription.

Seek urgent help for significant pain, strong light sensitivity, blurred or reduced vision, injury, chemical exposure, or a foreign body that will not rinse out. Contact a clinician promptly if discharge is thick, redness is worsening, swelling is spreading, or symptoms persist after avoiding the trigger. Contact-lens wearers should seek prompt advice for a red eye, particularly when pain or vision change is present.

Does the pattern fit allergy, conjunctivitis or another surface problem? Is there a scratch or retained particle? Which drops are suitable for me? How long should I avoid lenses, makeup and rubbing?