Derek Ainslie was an ophthalmologist and a pioneer in the development of vision corrective surgery. He was born in Hereford on 19 September 1919, the third child and second son of Janet (née Rogers) and William Ainslie, a surgeon and a fellow of the Edinburgh College. Derek Ainslie was educated at Hereford Cathedral Preparatory School, Sherborne and Clare College, Cambridge, going on to complete his clinical training at the Middlesex Hospital. He subsequently joined the RAMC and was en route to the Far East when the war ended. He remained in the Army, working in Africa until 1948 and reaching the rank of major. He underwent training in ophthalmology at Birmingham Eye Hospital, the Middlesex Hospital, and as senior resident officer at Moorfields Eye Hospital. Soon after completing his training he was appointed consultant ophthalmologist to the Middlesex and Moorfields Eye hospitals, in 1962. His work in ophthalmology was remarkable: he was a pioneer in corneal refractive surgery, using a microkeratome and surgical cryolathe. He worked closely in parallel with José Barraquer, a Spanish surgeon, in what was then a contentious field of work, but which has developed into the laser refractive surgery of today. Derek wrote extensively on the use of antibiotics in ophthalmology, corneal grafting and refractive keratoplasty. Sadly his work was interrupted in 1975 with the onset of a severe illness compounded by deteriorating vision from glaucoma. He retired prematurely at the age of 55. He examined for the diploma in ophthalmology and was a member of the Court of Examiners for the FRCS in ophthalmology. He was an adviser to the Merchant Navy from 1953 to 1963, and ophthalmic surgeon to Chorleywood College for Girls, a school for the partially sighted and blind. He married Robina Susan Lock in 1960, a medical practitioner. They had one son and two daughters. He had a wide interest in music, was a keen salmon and trout fisherman, and an ardent supporter of Arsenal Football Club. He died on 1 August 2006, and is survived by his third wife, Diana, children and grandchildren.