Born on 18 January 1865, the eldest child of John Heygate Vernon, an architect, and Caroline Miller, his wife. He was educated at Mill Hill School and at St George's Hospital, where he gained the W Brown exhibition, serving as house surgeon, demonstrator of anatomy and physiology, and clinical assistant in the orthopaedic and ophthalmic departments. He settled in Bournemouth, where he gained a large practice and took an active interest in municipal affairs. He was elected surgeon to the Royal Boscombe and West Hants Hospital in 1898, the hospital being amalgamated with the Royal Victoria Hospital in 1911 to form the Royal Victoria and West Hants Hospital. On his retirement in 1925 he was appointed consulting surgeon, and at the time of his death was chairman of the House Committee. Vernon was for many years surgeon to the 7th Hants Regiment, in which he finally attained the rank of lieutenant-colonel, RAMC(T), and received the Territorial Decoration. He was also surgeon to the fire brigade and took an active part in the local branch of the British Legion and the St John Ambulance Brigade and Association. He was a prime mover in the building of the Little Theatre at Bournemouth, and had served as president of the Bournemouth Medical Society, of the Dorset and West Hants branch and of the Bournemouth division of the British Medical Association. He married in 1891 Elizabeth Agnes Dence, who survived him, and died on 1 February 1931, being buried in Boscombe cemetery.