| bifocal | Having two foci. (05 Mar 2000) |
|---|---|
| bifocal lens | A lens used in cases of presbyopia, in which one portion is suited for distant vision, the other for reading and close work in general; the reading addition may be cemented to the lens, fused to the front surface, or ground in one-piece form; other bifocal lens's are the flat-top Franklin type, or blended invisible. (05 Mar 2000) |
| bifocal spectacles | Spectacles with bifocal lenses. See: lens. (05 Mar 2000) |