binoculars

views updated May 14 2018

binoculars Optical device, used with both eyes simultaneously, which produces a magnified image of a distant object or scene. It consists of a pair of identical telescopes, one for each eye, both containing an objective lens, an eyepiece lens, and an optical system (usually prisms), to form an upright image. Binoculars are classified by two numbers, such as 8×30, with the first number indicating the magnification and the second being the diameter of the objective lens (nearest to the object) in millimetres. Field glasses are a common type of binoculars.

binoculars

views updated May 23 2018

bin·oc·u·lars / biˈnäkyələrz/ • pl. n. an optical instrument with a lens for each eye, used for viewing distant objects.