a lens system consisting of two or more lenses on the same axis
put or add together
a whole formed by a union of two or more elements or parts
an enclosure of residences and other building (especially in the Orient)
(chemistry) a substance formed by chemical union of two or more elements or ingredients in definite proportion by weight
a transparent optical device used to converge or diverge transmitted light and to form images
electronic equipment that uses a magnetic or electric field in order to focus a beam of electrons
biconvex transparent body situated behind the iris in the eye; its role (along with the cornea) is to focuses light on the retina
