Lens

(Latin, a lentil or bean). Glasses used in mathematical instruments are so called because the double convex one, which may be termed the perfect lens, is of a bean shape.

Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

More on Lens from Fact Monster:

Related Content