What should you know about very bloodshot eye?

Redness occurs when small blood vessels on the white surface of the eye widen or become irritated. Allergic Conjunctivitis commonly brings itching, watering and redness in both eyes. Conjunctivitis may cause discharge, crusting or a gritty feeling and can spread between people. Dry air, smoke, dust, contact lenses, rubbing or a small surface vessel breaking can also cause marked redness. The appearance alone cannot identify the cause.

Wash your hands, avoid rubbing the eye and pause contact lens use until the eye feels normal and a clinician has advised you when to restart. A cool clean compress may ease irritation. Do not share towels, cosmetics or eye drops. Artificial tears may help dryness when suitable, but avoid using someone else’s prescription drops. Arrange an examination if redness persists, discharge develops or symptoms are getting worse.

Get urgent medical help for severe eye pain, sudden vision change, marked light sensitivity, an injured or chemically exposed eye, a bulging eye, severe headache with nausea, or redness while wearing contact lenses. Emergency assessment is especially important if something is stuck in the eye or the pupil looks unusual. Do not drive if vision is affected.

Could this be allergy, infection, dryness or a surface injury? Should I use any drops, and for how long? When can I safely wear contact lenses again? Which changes in pain, discharge or vision should prompt urgent review?