lensyoudaoicibaDictYouDict[lens 词源字典]
lens: [17] The Latin word for a ‘lentil’ was lēns; and when 17th-century scientists wanted a term for a round biconvex (lentil-shaped) piece of glass, they needed to look no further than lens. English lentil [13] itself comes via Old French from Latin lenticula, a diminutive form of lēns.
=> lentil[lens etymology, lens origin, 英语词源]
lens (n.)youdaoicibaDictYouDict
1690s, "glass to regulate light rays," from Latin lens (genitive lentis) "lentil," on analogy of the double-convex shape. See lentil. Of the eye from 1719.
In the vernacular of the photographer, anyone crowding to the front of a group, staring into the lens, or otherwise attracting attention to himself is known as a "lens louse." ["American Photography," vol. 40, 1946; the term dates from 1915]