binocular, binoculars, field glasses, opera glasses - an optical instrument designed for simultaneous use by both eyes

lens, lens system, lense - a transparent optical device used to converge or diverge transmitted light and to form images

light microscope - microscope consisting of an optical instrument that magnifies the image of an object

optical telescope - an astronomical telescope designed to collect and record light from cosmic sources

graticule, reticle, reticule - a network of fine lines, dots, cross hairs, or wires in the focal plane of the eyepiece of an optical instrument

sight - a optical instrument for aiding the eye in aiming, as on a firearm or surveying instrument