noun / adjective
bifocal
bye-FOH-kul/ˌbaɪˈfəʊkl/
A lens with two optical powers for near and distant vision, or having this design.
Her bifocal lenses help her read and see distant signs.
Etymology
The pieces mean “having two foci.” In the selected optical sense, this corresponds to two focusing powers: one for nearby objects and another for distant ones.
In context
they can also see well enough to drive the success rate rate with bifocal contacts is somewhere in the 60 to 70 percent range
More examples
- He looks through the lower part of his bifocals.
- The optician explains the two powers of a bifocal lens.
- She exchanges her reading glasses for bifocals.
Forms
bifocal · bifocals
Similar words
- progressive
- Uses a gradual range of lens powers rather than two sections.
- reading glasses
- Usually correct close vision without a separate distance section.