Red on the side of the eye: what to know

A sharply defined bright-red patch can happen when a tiny surface blood vessel leaks. It may look dramatic while causing little discomfort. Irritation from dry air, dust, smoke, contact lenses or rubbing can also make the white of the eye look red. Itching and watering are common features of [Allergic Conjunctivitis](/conditions/allergic-conjunctivitis/), while discharge and eyelid crusting can occur with [Conjunctivitis](/conditions/conjunctivitis/).

Look at whether the redness is a patch or spread across the eye, and note itching, discharge, light sensitivity, pain and changes in sight. A photograph can help you notice whether the area is expanding, but it cannot identify the cause.

Avoid rubbing the eye and wash your hands before touching your face. Stop wearing contact lenses until the eye feels normal and a clinician has advised that lenses are safe. A cool clean compress may soothe irritation. Do not share towels, cosmetics or eye drops, and avoid using someone else’s medicine.

If the redness keeps returning, follows an injury, or does not settle, arrange an assessment. The [Red Eye](/symptoms/red-eye/) guide may help you describe the pattern. Bring the name of any eye drops, allergy products or recent medicines to the appointment.

Seek urgent eye care for moderate or severe pain, blurred or reduced vision, marked sensitivity to light, a chemical splash, a penetrating injury, or redness with severe headache or nausea. Contact-lens wearers should seek prompt advice for a painful red eye because infections affecting the cornea can progress quickly. Emergency help is appropriate if vision is suddenly lost.

Ask: Is this a surface blood vessel or inflammation? Could my drops or contact lenses be contributing? Do I need treatment, and what symptoms should make me return urgently?