|
|
Definition of Bifocal
1. Adjective. Having two foci. "Bifocal eyeglasses"
Definition of Bifocal
1. a. Having two foci, as some spectacle lenses.
Definition of Bifocal
1. Adjective. (optics) Having two focal lengths ¹
2. Adjective. (context: of a correcting lens) Divided into two parts, one of which corrects for distance vision and the other for near vision ¹
¹ Source: wiktionary.com
Definition of Bifocal
1. a type of lens [n -S] - See also: lens
Medical Definition of Bifocal
1. Having two foci. (05 Mar 2000)
Lexicographical Neighbors of Bifocal
Literary usage of Bifocal
Below you will find example usage of this term as found in modern and/or classical literature:
1. Solid Geometry by Percival Frost (1875)
"If P be one extremity of a bifocal chord of a ... Let /, TH, n be the direction
cosines of a bifocal chord drawn ;e* y* z* through a point P (f, rj, ..."
2. An Introduction to the Ancient and Modern Geometry of Conics: Being a by Charles Taylor (1881)
"In order to pass to the determinate form of the bifocal property of the hyperbola
from ... The tangent to a bifocal conic makes equal angles with the focal ..."
3. Diseases of the eye: A Handbook of Ophthalmic Practice for Students and by George Edmund De Schweinitz (1916)
"... conversely, the trouble diminishes as the glass is brought nearer to the
eye.1 bifocal Lenses.—When presbyopic patients require two sets of glasses, ..."
4. Ophthalmic Record: A Monthly Review of the Progress of Ophthalmology (1900)
"Having had considerable trouble in convincing many of my presby- opic patients
of the advisability of wearing bifocal glasses, r*id also being annoyed after ..."
5. Spectacles and eyeglasses: Their Forms, Mounting and Proper Adjustment by Richard Jones Phillips (1908)
"bifocal Glasses.—When glasses of different focusing power are required for distant
and near ... Such bifocal glasses are also called Franklin glasses, ..."
6. Transactions of the American Ophthalmological Society Annual Meeting by American Ophthalmological Society (1897)
"A NEW ACHROMATIC GLASS FOR CATARACT FOR FAR VISION, AND A bifocal COMBINATION FOR
... I beg leave to present for your consideration this very useful bifocal ..."
7. A Manual of Personal Hygiene: Proper Living Upon a Physiologic Basis by Walter Lytle Pyle (1915)
"Any imperfection in the cementing of bifocal segments should be remedied at once.
... However, a bifocal lens is preferable in such cases. ..."
Other Resources:
Georgian