This study is investigating the effect of transplanting the patient’s own limbal stem cells in cases where vision is affected in only one eye. The treatment involves taking a biopsy from the patient's unaffected eye (their 'good' eye) and growing these cells in the laboratory on a donated placental tissue (human amniotic membrane). The sheet of cells is then transplanted into the patient's affected eye. The trial is being conducted at the Institute of Health and Society in Newcastle upon Tyne and expects to enrol 24 subjects by November 2013. Participants will be assessed up to three years after treatment.