Eye redness occurs when surface blood vessels dilate or become more visible. It ranges from mild pinkness to marked injection.
Common Causes
Dry eye, blepharitis, allergic or viral conjunctivitis, and minor irritation from smoke or contact lenses frequently cause redness. More serious conditions include bacterial keratitis, uveitis, scleritis, and acute glaucoma, which usually add pain or visual disturbance.
- Diffuse redness with discharge often reflects conjunctivitis
- Sectoral redness may indicate episcleritis or scleritis
- Ciliary flush around the cornea suggests intra‑ocular inflammation or glaucoma
- Subconjunctival haemorrhage causes a sharply demarcated red patch without pain
When to Worry
Redness with pain, photophobia, or reduced vision requires prompt assessment. Mild, non‑painful redness may respond to lubrication and trigger avoidance.
- Overuse of “whitening” drops can mask disease and worsen dryness
- Contact lens wearers with red, painful eyes should seek urgent review
- Systemic autoimmune or infectious diseases may present with red eyes
- Persistent unilateral redness warrants specialist evaluation
