Born on 16 February 1869 at The Priory, Holbeach, Lincolnshire, the eldest son and first child of Thomas Mordaunt Worth and Frances Charlotte Alley, his wife. He was educated at Bedford School and at St Bartholomew's Hospital. From 1893 to 1897 his address was at Sutton Bridge, but his time was spent in visiting Paris and Madrid and as surgeon to the SS *Britannia*. By this time he had determined to devote himself to ophthalmic surgery and after acting as clinical assistant at the Royal London Ophthalmic Hospital, Moorfields, he was appointed house surgeon and later ophthalmic surgeon to the Loughborough General Hospital. He then came to London and was appointed ophthalmic surgeon to the West Ham and East London Hospital. In 1905 he was elected surgeon to the Moorfields Hospital, an office he resigned in 1921 when he was made consulting surgeon. He continued to practise in London until 1929, when failing health obliged him to retire, and he lived for the rest of his life at Bar, Mawnansmith, Halford-Passage, Falmouth. He died there on 24 June 1936, survived by his widow and one son. He married on 22 November 1906 Janet, eldest daughter of Captain J Ritchie of Forfarshire. Worth did much to advance the treatment of strabismus in children. Starting on the assumption that the chief cause of concomitant squint in children is failure to fuse the two retinal images he invented "an amblyoscope" and a "four light test", by which he carried out the orthoptic treatment of the defect. By patience and demonstration he made good his theory, and orthoptic clinics are now in existence in most parts of the country. Worth, like his colleagues Malcolm Macdonald McHardy and Charles Devereux Marshall, was a keen yachtsman. He was a pioneer of the sport of yacht cruising, and made long cruises in a succession of small sailing yachts. He was president of The Little Ship Club, and from 1919 he was vice-commodore of the Royal Cruising Club. He was a man of outstanding ability, using the instruments and technique which he had himself invented with results which it was difficult to equal. Modest and retiring, he made friends of his patients and was especially beloved by his child patients. Publications: *A manual of diseases of the eye*, with C H May. London, 1906; 7th edition, 1934. *Squint; its causes, pathology and treatment*. London, 1903; 6th edition, 1929. The orthoptic treatment of convergent squint in young children. *Trans Ophthal Soc UK* 1901, 21, 245. Hereditary influence in myopia. *Ibid*. 1906, 26, 141. *Yacht cruising*. London, 1910; 2nd edition, 1921; regarded by yachtsmen as a classic. *Yacht navigation and voyaging*. London, 1927. These two books have made four of his boats, the four Terns, known all over the world.