My eyes have been red for days: what should I know?

Redness with itching and watering in both eyes can occur with allergic conjunctivitis. Dust, pollen, pets, smoke, dry air and prolonged screen use may irritate the eye surface. A gritty feeling, sticky discharge, one-sided redness or eyelid swelling changes the picture. Redness after contact-lens use deserves particular care because the cornea can become inflamed.

Do not rub your eyes. Pause contact lenses and eye makeup, wash your hands, and use a cool compress with a clean cloth. Lubricating drops may help dryness; ask a pharmacist which type fits your symptoms. Avoid sharing towels or eye products, and reduce exposure to smoke or a suspected allergen. Do not use leftover prescription drops without advice.

Get urgent help for severe pain, reduced or blurred vision, strong light sensitivity, an injury, chemical exposure, or swelling around the eye with fever. Contact an eye-care professional promptly if redness is painful, worsening, associated with thick discharge, or occurring in a contact-lens wearer. Persistent unexplained redness also merits an appointment.

Does the pattern suggest allergy, dryness or another cause? Do I need an eye examination or a swab? Which drops are safe for me, and when can I resume contact lenses?