bifocal
adjEtymology By surface analysis, bi- + focal, or, by surface analysis, bi- + foc(us) + -al.
1
Engineering, Natural sciences, Optics, Physical sciences, Physics Having two focal lengths.
- His hair is black and well greased, with individual strands of gray, and he wears wire-rimmed bifocals with a subtle brownish tint.1992, Neal Stephenson, Snow Crash, page 183:
2
Of a correcting lens Divided into two parts, one of which corrects for distance vision and the other for near vision.
- Derived terms
- bifocality