Sir Nicholas Harold Ridley. He changed the world, so that we might better see it.

Cataract surgery with intraocular lens (IOL) implantation has become the most common and most successful of all operations in medicine. Sir Harold Ridley's first cataract extraction with implantation of an IOL marked the beginning of a major change in the practice of ophthalmology. Millions of patients worldwide have benefited from Sir Ridley's invention, and are likely to continue to derive benefit from this device. However, the development of the IOL was not without its share of ups and downs. Sir Harold Ridley, the inventor of IOL, died at the age of 94, on 25 May 2001, and ophthalmology lost one of its greatest and most influential practitioners. We are happy that he lived to enjoy the fruits of his labour--to see the amazing improvements and the expansive growth that evolved in the cataract-IOL technique, from early and unsatisfactory operations in previous decades, to the superb results attainable today. The invention of the IOL has not been just the addition of one new form of treatment, but rather, Sir Harold's tiny disc-shaped sliver of plastic has changed the world so that our patients may better see it. This article presents a brief biographical sketch of Sir Harold and lists his major inventions and contributions to ophthalmology.