types:
autofocus
an optical device for focussing a camera or other instrument automatically
biprism
an optical device for obtaining interference fringes
camera lucida
an optical device consisting of an attachment that enables an observer to view simultaneously the image and a drawing surface for sketching it
coelostat
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
collimator
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
diffraction grating,
grating
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
Kerr cell
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
laser,
optical maser
an acronym for light amplification by stimulated emission of radiation; an optical device that produces an intense monochromatic beam of coherent light
lens,
lens system,
lense
a transparent optical device used to converge or diverge transmitted light and to form images
Nicol prism
optical device that produces plane-polarized light
planetarium
an optical device for projecting images of celestial bodies and other astronomical phenomena onto the inner surface of a hemispherical dome
polarimeter,
polariscope
an optical device used to measure the rotation of the plane of vibration of polarized light
optical prism,
prism
optical device having a triangular shape and made of glass or quartz; used to deviate a beam or invert an image
projector
an optical device for projecting a beam of light
stereoscope
an optical device for viewing stereoscopic photographs
viewer
an optical device for viewing photographic transparencies
anastigmat
compound lens or lens system designed to be free of astigmatism and able to form approximately point images
compound lens
a lens system consisting of two or more lenses on the same axis
contact,
contact lens
a thin curved glass or plastic lens designed to fit over the cornea in order to correct vision or to deliver medication
echelon
a diffraction grating consisting of a pile of plates of equal thickness arranged stepwise with a constant offset
erecting prism
a right-angled optical prism used to turn an inverted image upright
eyepiece,
ocular
combination of lenses at the viewing end of optical instruments
field lens
the lens that is farthest from the eye in an optical device with more than one lens
Fresnel lens
lens composed of a number of small lenses arranged to make a lightweight lens of large diameter and short focal length
intraocular lens
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
meniscus
(optics) a lens that is concave on one side and convex on the other
eyeglass,
monocle
lens for correcting defective vision in one eye; held in place by facial muscles