Thomas Keith Selfe Lyle was born on 26 December 1903, the son of Herbert Willoughby Lyle FRCS, (see *Lives of the Fellows* 1952-64) and his wife Elizabeth Ada (née Selfe). He was educated at Dulwich College, where he distinguished himself in the school, the OTC and the Rugby XV; at Sidney Sussex College, Cambridge, and at King's College Hospital, where he won the Burney Yeo Scholarship, the Todd Prize for clinical medicine and the Nettleship Prize for ophthalmology. After appointments in the neurological department at King's College Hospital he went to the Royal Westminster Ophthalmic Hospital, and subsequently became surgeon to Moorfields Eye Hospital and ophthalmic surgeon to King's College Hospital and the National Hospital for Nervous Diseases. He was Dean of the Institute of Ophthalmology and an examiner for several professional bodies. At the Royal College of Surgeons he was a member of the Court of Examiners (ophthalmology), a co-opted member of Council and Chairman of the Specialist Advisory Committee in Ophthalmology. He served with the RAF Volunteer Reserve from 1939 to 1946, was mentioned in dispatches and later was consultant to the RAF and Ministry of Aviation reaching the rank of Air Commodore. He was most interested in the Order of St John of Jerusalem and did much to maintain the excellence of the Ophthalmic Hospital in Jerusalem. He became a knight grand cross of the Order of St John in 1981 and was a knight of the Holy Sepulchre. Among other awards he received the Doyne Medal and the Richardson Cross Medal. He was President of the United Services Section of the Royal Society of Medicine, President of the British Orthoptic Board and Master of the Society of Apothecaries. He was co-editor of five editions of *Practical orthoptics in the treatment of squint*, Worth's *Squint*, May and Worth's *Diseases of the eye*, and his father's *Applied physiology of the eye*. He was characterised by great energy and enthusiasm, doing everything at the double. He was a keen tennis player, excellent horseman and member of the ski club. He enjoyed music and travel. In 1949 he married Jane Maxwell and they had three daughters and a son. He died on 9 May 1986 aged 82.