Perspex

Trademark for a clear, lightweight, tough plastic first produced in the USA in 1930. It is widely used for watch glasses, advertising signs, domestic baths, motorboat windscreens, aircraft canopies, and protective shields. Its chemical name is polymethylmethacrylate (PMMA). It is manufactured under other names: Plexiglas, Lucite, Acrylite, and Rhoplex (in the USA), and Perspex and Oroglas (in Europe).

During World War II, the British surgeon Harold Ridley (1906–2001) operated on fighter pilots who had splinters of PMMA from broken cockpit windows in their eyes. He noticed that the eye tolerates this material surprisingly well. Based on this discovery, he developed the first artificial eye lens which he implanted in 1949. Millions of cataract patients later benefited from this discovery.