Mooren's ulcer is a chronic, painful peripheral ulcer of the cornea. Its cause is unknown but it can or will lead to loss of vision if untreated. Severe pain is common in patients with Mooren's ulcer and the eye(s) may be intensely reddened, inflamed and photophobic, with tearing. The disease is rare in the northern hemisphere but more common in southern and central Africa, China and the Indian subcontinent. There are a number of treatments used such as anti-inflammatory drugs (steroidal and non-steroidal), cytotoxic drugs (topical and systemic), conjunctivectomy and cornea debridement (superficial keratectomy). There is no evidence to show which is the most effective amongst these treatment modalities.