The optical lens is named after the lentil, not the other way around — because early lenses were shaped like the flat, biconvex seed of this ancient crop.
A small, flat, round edible seed of a leguminous plant, high in protein and widely used in soups, stews, and other dishes.
From Old French lentille, from Latin lenticula (a small lentil), diminutive of lens (lentil), genitive lentis. The optical lens was named after the lentil because of its similar biconvex shape. Key roots: lens (Latin: "lentil").
The optical lens is named after the lentil, not the other way around — because early lenses were shaped like lentil seeds (biconvex, rounded on both sides). In German, Linse means both lentil and lens, preserving the original connection. Lentils are one of the oldest cultivated crops in human history, with archaeological evidence of cultivation dating to 8000 BCE in the Near East. The biblical story of Esau selling