Introduction
Sir Nicholas Harold Lloyd Ridley, known as Harold (10 July 1906 – 25 May 2001), was an English ophthalmologist who invented the intraocular lens (IOL) in the cure of cataract blindness. Through this pioneering surgery more than 300 million people worldwide have had their sight restored in what is now one of the most common and sophisticated surgical procedures that usually takes 10-20 minutes to perform.
Harold Ridley was born in Kibworth Harcourt, Leicestershire, the son of Nicholas Charles Ridley also an ophthalmologist. He was educated at Charterhouse School before studying at Pembroke College, Cambridge and completed his medical training in 1930 at St Thomas’ Hospital. He was elected a Fellow of The Royal College of Surgeons (at the youngest possible age of 25) and was appointed a consultant at Moorfields Hospital London in 1938 and St Thomas’s Hospital London in 1946.



The development of the cataract operation and invention of the intraocular lenses
During World War II, Ridley saw Royal Air Force casualties with eye injuries, including Squadron Leader Gordon “Mouse” Cleaver of 601 Squadron. Ridley observed that when splinters of acrylic plastic from aircraft cockpit canopies became lodged in their eyes, this did not trigger inflammatory rejection as they did with the metal splinters.
This led him to propose the use of artificial lenses to treat cataract. He had a lens manufactured using the same material – brand name Perspex, made by ICI – and on 29 November 1949 at St Thomas’ Hospital, Ridley achieved the first implant of an intraocular lens, although it was not until 8 February 1950 that he left an artificial lens permanently in place in an eye. The first lens was manufactured by the Rayner company of Brighton & Hove, East Sussex, a company which continues to manufacture and market intraocular lenses today. The first IOL implant in the United States was performed in 1952: a Ridley-Rayner lens implanted at the Wills Eye Hospital in Philadelphia.
Ridley pioneered this treatment in the face of prolonged strong opposition from the medical community. He worked hard to overcome complications, and had refined his technique by the late 1960s. With his pupil Peter Choyce he eventually achieved worldwide support for the technique. The intraocular lens was finally approved as “safe and effective” and approved for use in the US by the Food and Drug Administration in 1981. Cataract extraction surgery with intraocular lens implantation is now the most common type of eye surgery in the world.