What should you know about red eye infection?

Infectious conjunctivitis can affect the clear surface over the white of the eye and the inner eyelids. Redness may occur with gritty discomfort, watering, sticky discharge or eyelids that are difficult to open after sleep. One eye may become involved before the other. The [Conjunctivitis](/conditions/conjunctivitis/) page explains this pattern.

Not every red eye is infectious. Itching and exposure to pollen or other triggers fit [Allergic Conjunctivitis](/conditions/allergic-conjunctivitis/), while dryness, a small surface blood vessel or a deeper eye problem can look different. A clinician uses the history and examination to separate these possibilities.

Wash hands after touching the face, clean discharge gently with fresh water, and use separate towels and pillowcases. Avoid sharing eye cosmetics, eye drops or contact lenses. Stop wearing contact lenses until symptoms have cleared and a clinician or optometrist advises restarting. Do not use leftover antibiotic drops; treatment depends on the cause and examination findings. Resting the eyes and a cool clean compress may ease discomfort.

Get urgent care for moderate or severe pain, reduced vision, strong light sensitivity, an injury, chemical splash, marked swelling, or symptoms in a contact-lens wearer. Seek medical advice if discharge is heavy, symptoms are worsening, or the eye is not settling. Babies and people with weak immune systems need a lower threshold for assessment.

Ask whether the pattern suggests infection, allergy or irritation, whether testing is needed, and how long to avoid lenses or close face-to-face contact. Tell the clinician about discharge colour and timing, recent illness, new cosmetics, contact-lens habits and any change in vision.