trifocaladj.n.
/trʌɪˈfəʊkəl/ A. adj. † a. (See quot. 1826) Obsolete.
ΘΚΠ
the world > health and disease > healing > ophthalmology or optometry > aids to defective vision > [adjective] > types of spectacles
steel-rimmeda1400
steelbowed1606
young1667
near-sighted1796
trifocal1826
steel-bow1834
pantoscopic1836
window glass1885
bifocal1888
horn-rimmed1894
pebbled1928
thick-lensed1946
single-vision1962
wire-rim1968
wire-frame1977
Lennon1984
1826 J. I. Hawkins in Repertory Patent Inventions (1827) 3 386 When three pair [of glasses] are worn in one frame..which I denominate trifocal spectacles, the opening should be a circle of one inch diameter.
b. Of a lens: having three parts with different focal lengths. Of spectacles: having such lenses.
ΘΚΠ
the world > health and disease > healing > ophthalmology or optometry > aids to defective vision > [adjective] > types of spectacles > types of spectacle lens
astigmatic1881
toric1890
trifocal1921
multifocal1928
pebble-grained1943
omnifocal1962
1921 Amer. Jrnl. Ophthalmol. 4 406/2 The writer does not claim that every presbyope should have a pair of trifocal spectacles.
1928 S. Duke-Elder Pract. Refraction xxiii. 343 For some purposes tri-focal lenses are advocated.
1969 K. Vonnegut Slaughterhouse-Five v. 93 She was wearing tri-focal lenses in harlequin frames.
B. n.
A trifocal lens; usually plural, trifocal spectacles.
ΘΚΠ
the world > health and disease > healing > ophthalmology or optometry > aids to defective vision > [noun] > spectacles > other types of spectacles
half-moon glasses1607
half-moon spectacles1607
blinkers1732
temple-spectacles1762
reading glass1853
distance glasses1864
horn spectacles1893
bifocal1899
trifocal1899
horn-rims1927
harlequin spectacles1940
harlequin glasses1945
library frame1948
aviator1951
library glasses1959
library spectacles1962
multifocals1962
wire-rim1968
1899 J. Thorington Refraction (ed. 3) xi. 283 Trifocals.—Occasionally, a patient is not content with bifocals, but will demand a focal point somewhere between infinity and his working distance.
1946 C. Berens & J. Zuckerman Diagnostic Exam. Eye i. xii. 319 (caption) Double~segment panoptik trifocal for sculptors.
1962 L. S. Sasieni Princ. & Pract. Optical Dispensing vii. 172 Where the gardener does not need a distance correction, the best combination may be reading and weak intermediate. A trifocal is the obvious alternative.
1973 R. Hayes Hungarian Game xxiv. 147 He was a pallid man with eyes that were weirdly distorted by trifocals.
This entry has not yet been fully updated (first published 1986; most recently modified version published online September 2021).
<
adj.n.1826