| 释义 |
biˈfocal, a. and n. orig. U.S.
[bi-2.]
A. adj. Having two foci; spec. designating spectacles with two segments of different focal lengths.
1888G. M. Gould in Med. & Surg. Reporter LIX. 545 (title) A new style of bi-focal lenses. 1895Pop. Sci. Monthly Aug. 470 Ordinary bifocal glasses. 1938E. Ambler Cause for Alarm ii. 29 A..man of about fifty with rimless, bi-focal spectacles. 1968New Scientist 21 Mar. 619/2 Bifocal and trifocal spectacles have been a blessing.
B. n. pl. Bifocal spectacles.
1899Ophthalmic Rev. XVIII. 270 Dr. G. C. Harlan..had shown..a pair of bi-focals made by Borsch in which the reading part is formed of a circular lens 15 mm. in diameter..sunk into the distant lens. 1936G. B. Shaw Simpleton 31 Wears glasses. Bi-focals. 1960J. Wain Nuncle 6 Harley Street types looking at me through their bifocals. |