noun
bifocal lens
Technical term for a lens with two distinct focal lengths, typically used in eyeglasses or optical instruments.
二重焦点レンズは遠くと近くの両方を見やすくする。
Bifocal lenses make it easier to see both far and near.
A more common term for bifocal or progressive lenses in everyday contexts; 二重焦点レンズ is more technical.
Compound of 二重 (double) + 焦点 (focal point) + レンズ (lens), directly describing a lens with two focal points.