[bahy-foh-kuh l, bahy-foh-]
- Chiefly Optics. having two foci.
- (of an eyeglass or contact lens) having two portions, one for near and one for far vision.
- bifocals, bifocal eyeglasses or contact lenses.
Origin of bifocal
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for bifocal
His most direct contribution to medicine was the invention for his own use of bifocal eyeglasses.
Any other fish or mammal would have been just as likely as Anableps to begin the development of a bifocal eye.Parallel Paths
Thomas William Rolleston
- optics having two different focuses
- relating to a compound lens permitting near and distant vision
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for bifocal
Online Etymology Dictionary, © 2010 Douglas Harper
- Having two focal lengths.
- Having one section that corrects for distant vision and another that corrects for near vision.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.