Does allergic conjunctivitis cause red eye?

Allergic conjunctivitis inflames the thin surface covering the eye and the inside of the eyelids. Small blood vessels become more visible, giving the white of the eye a pink or red appearance. Itching and watering often accompany the redness, and both eyes may be involved. Dryness, infection, injury, contact lens problems, and other eye conditions can also cause red eye, so colour alone cannot identify the cause.

Avoid rubbing your eyes and take a break from eye makeup while they are irritated. A cool compress over closed eyes may ease redness and swelling. Limit exposure to known allergens, wash your hands after outdoor activities, and use clean towels. Ask a pharmacist or doctor about appropriate allergy treatment, particularly before using medicated or redness-relieving drops.

Seek prompt assessment for eye pain, light sensitivity, blurred or reduced vision, injury, a very swollen eyelid, or redness in a contact lens wearer. Immediate help is needed for sudden vision loss, severe pain, or a chemical splash; rinse a chemical-exposed eye with clean water while arranging emergency care.

Ask whether the redness matches allergy or another eye condition, which triggers to avoid, and which treatment is safe for you. Explain whether one or both eyes are red, how quickly it began, whether there is discharge or pain, and whether your vision has changed.