adjective
- Chiefly Optics. having two foci.
- (of an eyeglass or contact lens) having two portions, one for near and one for far vision.
noun
- bifocals, bifocal eyeglasses or contact lenses.
pl n
- a pair of spectacles with bifocal lenses
adjective
- optics having two different focuses
- relating to a compound lens permitting near and distant vision
“bifocal spectacles,” 1899, see bifocal. Conceived by Benjamin Franklin, but called by him double spectacles.
adj.
- Having two focal lengths.
- Having one section that corrects for distant vision and another that corrects for near vision.