Red Eye: Causes, Care and Urgent Warning Signs

Red eye happens when surface blood vessels become more visible because the eye is irritated or inflamed.

One or both eyes may look pink, bloodshot, or have a local red patch. Associated symptoms can include itch, grittiness, burning, watering, sticky discharge, a swollen eyelid, light sensitivity, blurred vision, or the feeling that something is under the lid. Pain and changes in sight are particularly important details.

Get urgent eye care for severe pain, reduced or altered vision, marked light sensitivity, a chemical splash, an eye injury, a pupil that looks unusual, severe headache with nausea, or a contact-lens wearer with a painful red eye. Do not rub an injured eye or try to remove an embedded object. A sudden red eye with these symptoms needs assessment even if the redness later seems to ease.

These causes are listed alphabetically, not as a ranking. Allergic conjunctivitis often includes itching and watering. Conjunctivitis can cause redness and discharge. Dry eye may feel gritty or tired, especially with screen use or dry air. A foreign body can produce a sharp scratchy sensation, while a stye is a tender lump near the eyelid edge.

Assessment begins with the timing, whether one or both eyes are involved, contact-lens use, injury, products used around the eye, and any vision change. The clinician may check vision, pupils, eyelids, eye movement, the surface of the eye, and the area beneath the lids. Staining drops or other tests can reveal a surface scratch or retained material.

Treatment differs according to the cause. Cool compresses and trigger avoidance may soothe allergy-related irritation. Lubricating drops can be useful for dry eye. Conjunctivitis may need hygiene measures or targeted treatment depending on the type. A clinician can remove a foreign body safely and assess for a scratch. Avoid using another person's drops, steroid eye drops, or contact lenses until you have been advised it is safe.

Wash hands before touching the eyes or handling lenses, replace eye cosmetics as directed, and do not share towels or makeup. Use protective eyewear for dusty work or tasks with flying particles. Take visual breaks during close work and follow contact-lens cleaning and replacement instructions carefully.

Report discharge, lid swelling, itching, pain, headache, fever, recent cold symptoms, injury, chemical exposure, contact-lens use, or any change in vision. Redness with pain or impaired sight is different from simple irritation and should not be managed by trial and error.

Untreated surface injury or infection can remain uncomfortable and may threaten the front of the eye in some situations. Recurrent redness can also point to an ongoing exposure, dry-eye problem, lid condition, or allergy that benefits from a more durable management plan.