from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Having two focal lengths.
- adj. Having one section that corrects for distant vision and another that corrects for near vision, as an eyeglass lens.
- adj. 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).
- n.pl. Eyeglasses with bifocal lenses.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Having two focal lengths
- adj. Divided into two parts, one of which corrects for distance vision and the other for near vision
from the GNU version of the Collaborative International Dictionary of English
- adj. Having two foci, as some spectacle lenses.
- n. a bifocal lens.
from The Century Dictionary and Cyclopedia
- Having two foci.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. having two foci
Sorry, no etymologies found.
He produced other inventions as well, such as bifocal eyeglasses and the efficient Franklin stove.
No intermediate lenses but u get optimal distance correction as well as reading. .and u will also look younger with them glasses as they don't have the telltale "bifocal" line.
If not, then you got something "off the rack", and it may just be that the "bifocal" part covers more of the lens than necessary.
I've got progressive bifocals, and the "bifocal" part occupies
(progressive or otherwise) wherein the "bifocal" part occupied the entire bottom half of the lens, and they swore they'd never go back to bifocals again.
I've got progressive bifocals, and the "bifocal" part occupies a small semi-circular region at the bottom of the lens, and I have clear vision throughout the rest of the lens for distant objects (no "sweep spot).
Pastor White is fifty-something with receding brown hair that he combs straight back, and wears large bifocal glasses that cover half his bearded face.
Watch Your Step Dr. Auerbach notes that wearing bifocal glasses to correct the classic over-50 vision issue—presbyopia, or the inability to focus on objects nearby—can lead to stumbles and falls; the lower part of the glasses, meant for reading, can blur the image down at your feet.
Our leaders must become bifocal, if not bipartisan.
And now at this point, we can actually do such detailed design so that we could actually do a full, what's called a progressive lens and no-line bifocal, to cut multiple curves on the back of a lens now to actually a full, no-line bifocal on the back of a lens.