| Inflammation of the sclera, called scleritis, can cause intense, boring pain and, if severe, could be associated with life-threatening systemic disease. |
| The four main causes of painful red eyes are corneal lesions, uveitis, acute glaucoma, and scleritis. |
| However, the cause of scleritis is often not discovered. |
| Deep scleritis is more persistent and less subject to periods of intermission than episcleritis. |
| Other eye complications of scleritis include uveitis, cataracts, keratitis, and glaucoma. |
| Conditions requiring referral to an ophthalmologist are orbital cellulitis, hyphaema, scleritis, iritis or uveitis, acute angle closure glaucoma, and corneal abrasions. |
