What should you know about eye red and crusty in morning?

Crusting forms when tears, mucus and discharge dry during sleep. [Conjunctivitis](/conditions/conjunctivitis/) may cause redness, watering, gritty discomfort and discharge; infectious cases can spread between people. [Allergic Conjunctivitis](/conditions/allergic-conjunctivitis/) more often brings itching, watering and symptoms in both eyes, especially after exposure to a trigger. A single red eye can have other causes, so the appearance on waking does not establish the diagnosis.

Wash your hands before and after touching the area. Soften crusts with clean warm water and a fresh cotton pad or clean cloth, wiping from the inner corner outward and using a separate pad for each eye. Do not share towels, pillowcases or eye cosmetics, and avoid contact lenses until symptoms have settled and advice has been given. Arrange a review if discharge continues, the eye becomes more uncomfortable or symptoms affect daily activities.

Get urgent help for significant eye pain, reduced or blurred vision, strong light sensitivity, marked swelling, an injury, chemical exposure or a red eye in a contact-lens wearer. Seek prompt advice if a newborn has eye discharge, or if symptoms are rapidly worsening. These features need assessment because they may involve more than uncomplicated irritation.

Does the discharge look infectious or allergic? Should I pause contact lenses or any eye drops? How long should cleaning continue, and which changes mean I need same-day assessment?