The word “lens” comes from the name of the lentil bean because of the similarity in shape of the bean and a converging lens. Lenses have been used for over three thousand years. It’s possible that ancient Assyrians used them as a burning glass to start fires. A burning glass is mentioned in a play by Aristophanes written in 424 B.C.E. Roman emperors used corrective lenses and knew that glass globes filled with water were able to produce magnified images. Al-Haitham (Alhazen; 965-1038 C.E.) wrote the first major textbook on optics that was translated into Latin in the twelfth century and influenced European scientists. Shortly thereafter, in the 1280s, eyeglasses were used in Italy. The use of diverging lenses to correct nearsightedness (myopia) was documented in 1451.

Today, lenses used in eyeglasses and cameras are usually made of lightweight plastics that are cheaper and more durable than traditional glass lenses.