an optical device for focussing a camera or other instrument automatically

an optical device for obtaining interference fringes

an optical device consisting of an attachment that enables an observer to view simultaneously the image and a drawing surface for sketching it

optical device used to follow the path of a celestial body and reflect its light into a telescope; has a movable and a fixed mirror

optical device consisting of a tube containing a convex achromatic lens at one end and a slit at the other with the slit at the focus of the lens; light rays leave the slit as a parallel beam

optical device consisting of a surface with many parallel grooves in it; disperses a beam of light (or other electromagnetic radiation) into its wavelengths to produce its spectrum

optical device that distributes the light of a lamp evenly

optical device that helps a user to find the target of interest

optical device consisting of a transparent cell with two electrodes between two polarizing media; passes light only if the two planes of polarization are parallel; used as a high-speed shutter or to modulate a laser beam

an acronym for light amplification by stimulated emission of radiation; an optical device that produces an intense monochromatic beam of coherent light

a transparent optical device used to converge or diverge transmitted light and to form images

optical device that produces plane-polarized light

an optical device for projecting images of celestial bodies and other astronomical phenomena onto the inner surface of a hemispherical dome

an optical device used to measure the rotation of the plane of vibration of polarized light

optical device having a triangular shape and made of glass or quartz; used to deviate a beam or invert an image

an optical device for projecting a beam of light

optical device that produces plane-polarized ultraviolet light

an optical device for viewing stereoscopic photographs

an optical device for viewing photographic transparencies

compound lens or lens system designed to be free of astigmatism and able to form approximately point images

a lens designed to correct astigmatism

a lens that focuses the image in a camera

a lens system consisting of two or more lenses on the same axis

lens used to concentrate light on an object

a thin curved glass or plastic lens designed to fit over the cornea in order to correct vision or to deliver medication

lens such that a beam of light passing through it is brought to a point or focus

a lens made of optical crown glass

a lens such that a parallel beam of light passing through it is caused to diverge or spread out

a diffraction grating consisting of a pile of plates of equal thickness arranged stepwise with a constant offset

a right-angled optical prism used to turn an inverted image upright

combination of lenses at the viewing end of optical instruments

the lens that is farthest from the eye in an optical device with more than one lens

lens composed of a number of small lenses arranged to make a lightweight lens of large diameter and short focal length

an artificial lens that is implanted into the eye of someone to replace a damaged natural lens or someone who has had a cataract removed

(optics) a lens that is concave on one side and convex on the other

lens for correcting defective vision in one eye; held in place by facial muscles

the lens or system of lenses in a telescope or microscope that is nearest the object being viewed