Bifocals

Bifocals, eyeglasses with two distinct optical powers, are most commonly prescribed to people with presbyopia who also require a correction for myopia, hyperopia, and/or astigmatism. ==History== Benjamin Franklin is generally credited with the invention of bifocals. Historians have produced some evidence to suggest that others may have preceded hi...
Found on http://en.wikipedia.org/wiki/Bifocals

bifocals

Eyeglasses that incorporate two different powers in each lens, usually for near and distance corrections
Found on http://www.eyeglossary.net/

bifocals

noun eyeglasses having two focal lengths
Found on http://wordnetweb.princeton.edu/perl/webwn?s=bifocals

bifocals

bifocals Eye glasses with lenses that are divided into two parts. The upper half is for looking at things far away and the lower half is for reading or for looking at things that are near.
Found on http://www.wordinfo.info/words/index/info/view_unit/841/
No exact match found