Having two foci, as some spectacle lenses.
- Having two focal lengths.
- Having one section that corrects for distant vision and another that corrects for near vision, as an eyeglass lens.
- Embodying two distinct and often conflicting goals, interests, or courses of action: "a smoothly functioning bifocal mind” ( John McPhee). "A bifocal monetary policy . . . has kept one eye on the money supply and the other on interest rates” ( Edward Meadows).
- Eyeglasses with bifocal lenses.