Although Alexander Fleming discovered penicillin in 1928, it was only in 1938 that Howard Florey and Ernst Chain found a way to produce it, demonstrating it only in 1942.
Adolph Fick first suggested contact lenses in 1888, and although two companies manufactured lenses out of glass, it wasn’t until 1948 when Kevin Tuohy invented the soft plastic lens.
Bar codes were invented by Bernard Silver and Norman Woodland in 1948. Their system used light to read a set of concentric circles, but they had to wait two decades before the advent of computers and lasers made their system practical. (However, the bar code system in use today is the Universal Product Code, introduced by IBM in 1973. The first bar coded item sold was a pack of gum in 1974.)
