It was the curved shape of the lens that led to its name being borrowed, in the late 17th century, from the Latin name of the lentil plant, lens culinaris. In French, another word for lens is objectif ...

It’s often called the optic that best approximates human vision, but approximation is relative. An Object Lesson. But the concept of “normal vision,” let alone the 50-mm lens’s ability to reproduce it ...