Sir Harold Ridley, who died on May 25th aged 94, was a modest giant of science, who established one of the great milestones in medical history. Despite fierce professional opposition - and the limits of the early equipment for conducting microsurgery - he developed an approach to eye surgery that has saved the sight of some 200 million people around the world by the insertion of a man-made lens.
About six million of the estimated seven million cataract operations carried out this year will depend on intraocular lens (IOL) implantation, a technique he first performed at St Thomas's Hospital, London, in 1949.
Although those methods are now outdated, with subsequent refinements perfected by him and other ophthalmologists, IOL has become one of the most common and effective of all surgical procedures worldwide.
Since cataracts, regions of dead cells that occur within the eye lens and turn it hard and opaque, are responsible for half of the world's blindness, the World Health Organisation is lobbying for greater use of the technique as part of its "Vision 20/20" campaign to eradicate avoidable blindness by 2020.
Harold Ridley was born at Kibworth Harcourt, Leicestershire, the elder son of a naval surgeon who specialised in ophthalmology. He went to Charterhouse School and Pembroke College, Cambridge, where he studied natural sciences before qualifying as a doctor at St Thomas's.
He was drawn to surgery and, at 25, decided to specialise in ophthalmology; in 1938, he became a consultant at Moorfields eye hospital, London, where he began to develop his early thoughts on better ways of treating cataracts.
War service in the Royal Army Medical Corps took him in 1942 to Africa, where he studied, and improved the diagnosis of, river blindness (onchocerciasis).
One of the people who was to have an enormous influence on Harold Ridley was Gordon Cleaver, a young Battle of Britain pilot. Machine-gun fire from a German fighter had shattered his cockpit canopy, and splinters of perspex had destroyed one eye and severely damaged the other; he was blinded in the air, and forced to bale out. "Mouse" Cleaver had 17 operations during the war, and his sight in one eye was saved. In 1991, he had a cataract operation with a lens implant. He died, with good sight, in 1997.
Before going to Africa, Harold Ridley had been a member of the surgical team treating young pilots at Moorfields, and had been struck by the fact that, although a patient's better eye was peppered with fragments of perspex, there was no foreign-body reaction to it. Though lodged in the eyeball, these splinters were apparently inert, and caused no adverse reactions in the sensitive tissues of the eye.
At the time, the established method of treating cataracts was either to remove or crush the opaque lens, after which the patient was issued with pebble-thick spectacles giving only limited pinpoint vision.
He was already wrestling with the idea of how to replace an extracted lens with an artificial one, without causing a horrendous reaction, and his observations of Cleaver's progress, and of other pilots' injuries, helped to provide him with the answer.
On returning to Moorfields at the end of the war, he asked John Pike, the senior optical scientist at the firm Rayner Intraocular Lenses, to help design and manufacture implantable lenses.
After exploring perspex, they decided that the new lenses needed a more refined material. John Holt, of ICI, provided the answer with the development of transpex.
At St Thomas's, on November 29th, 1949, Harold Ridley performed the first intraocular lens operation on a 42-year-old woman. He recommended a two-stage operation; three months later, he implanted a new artificial lens. Since then, these devices have undergone continuous evolution in design, weight and manufacturing process.
Over the first 18 months, he cautiously repeated the process a few times, before news of his work leaked out. He suspected - rightly as it turned out - that the innately conservative medical profession would react poorly; and indeed, traditionalists condemned his work out of hand.
Eye surgery had had a history of disastrous failures, and, having spent their careers taking foreign bodies out of eyes, ophthalmologists were not now enthused by a treatment that necessitated inserting a huge new one.
However, by the early 1970s, the technique had been established as a routine treatment with a very refined procedure. Intraocular lens implantation for cataract surgery became safe and fast, and restored wide, clearer vision without the use of cumbersome spectacles.
Harold Ridley is survived by his wife, two sons and a daughter.
Nicholas Harold Lloyd Ridley: born 1906; died May 2001.