(In singular and plural) binoculars containing two pairs of triangular prisms, introduced so as to shorten the instrument and improve the stereoscopic effect.
Origin
Early 20th century; earliest use found in British Optical Journal.
Definition of prism binocular in US English:
prism binocular
noun
(In singular and plural) binoculars containing two pairs of triangular prisms, introduced so as to shorten the instrument and improve the stereoscopic effect.
Origin
Early 20th century; earliest use found in British Optical Journal.