The Legacy Collection

2018 Legacy Inductee

Claud Allen Worth, MD (1869–1936)

Legacy Summary Statement

A pioneer in the field of strabismus, an advocate of early surgery and orthoptic treatment, this British ophthalmologist was a proponent of several theories of binocular vision as well as a prolific author, inventor and great thinker of his time. Worth was a problem solver who loved to make gadgets and was capable of accomplishing anything that drew his interest.


Born in Holbeach in 1869, Claud Alley Worth came from an ancient Lincolnshire family. He was educated at Bedford Modern School and trained in medicine at St. Bartholomew’s Hospital, obtaining his medical degree in 1893 and FRCS in 1898. He became interested in ophthalmic surgery, and as was common in those days he traveled to Europe to further his studies. He studied with experts in Paris and Madrid and served as a surgeon for S.S. Britannia.

He became a house officer at the Royal London Ophthalmic Hospital, Moorfields (later Moorfields Eye Hospital), then served as ophthalmic surgeon at Loughborough General Hospital. He returned to London to West Ham and East London Hospital and in 1905 was elected to Moorfields. Married by then with one son, it was here that he put his theories into practice and invented instruments still in use today. He was considered the father of modern orthoptics. He developed the first amblyoscope to treat suppression and promote fusional amplitudes. He used red and green ground glass in conjunction with his four-dot test to assess fusional ability, both instruments bearing his name. He designed a set of ivory balls in diminishing sizes, placed on his exam room carpet to test children’s acuity. He was instinctively trusted by children, always gentle and with quiet persistence.

In 1900, Worth coauthored May and Worth’s Manual of Diseases of the Eye. In 1903 he published one of the first books on the etiology of strabismus and its treatment. He was the first to classify the three grades of binocular vision. He believed that childhood ‘squint’ was caused by a congenital defect in the fusion center. He later agreed with Chavasse that it was due to an obstruction in the development of the binocular reflexes. Squint; its Causes, Pathology, and Treatment became a household name worldwide for all who studied strabismus. This went into several editions. The 7th edition was co-authored by Bernard Chavasse, a close friend and colleague – and fellow yachtsman! Known familiarly as ‘Worth and Chavasse’, this continued as the standard textbook for orthoptic students and ophthalmologists with an interest in strabismus. Later editions were published by their disciples at Moorfields; first, T. Keith Lyle, and then with Kenneth Wybar. The title became ‘Worth and Chavasse’s Squint: The Binocular Reflexes and the Treatment of Strabismus.

Worth was not just an expert in the field of ophthalmic surgery and strabismus. He was also a pioneer in the early days of yacht cruising, which became a major leisure sport in a country that is a small island surrounded by a delightful navigable tidal coastline. He became a master yachtsman and wrote two textbooks on sailing, Yacht Cruising (1910) and Yacht Navigation and Voyaging (1927.) The illustrations were drawn by Harrison Butler, another fellow yachtsman, and ophthalmologist. Worth designed many practical devices including an ingenious method to prevent an anchor from dragging.

Worth built his first boat as a teenager. He designed and built several yachts and his last one, Tern IV, was discovered in France around twenty years ago and was brought back to Cornwall. Plans to restore the boat to benefit blind children were abandoned due to the expenses involved. To anyone interested in the complex subject of yacht navigation, the various gadgets designed by Worth, and his sailing experiences, his books are quite detailed and informative.

It is fitting that after retirement in 1929 due to ill-health, he spent his last few years in Falmouth, a sailing mecca on the Cornish coast in the south of England. This is where he died in 1936 after a productive and illustrious career.

Claud Allen Worth Headshot