bifocals

英 [baɪ'fəʊkəlz] 美[,baɪ'foklz]

TEM8

形容词: bifocal;

bifocals 双光眼睛

前缀bi-, 二。词根foc, 焦点，见focus.

bifocals (n.): "bifocal spectacles," 1899, see bifocal. Conceived by Benjamin Franklin, but called by him double spectacles.