The largest segment of this industry--about one-third of industry sales--is sighting, tracking, and fire control equipment, much of which is used in missile systems,

This category covers establishments primarily engaged in manufacturing instruments and apparatus that measure an optical property

W. T. Welford has written:

'Aberrations of optical systems' -- subject(s): Aberration, Design and construction, Geometrical optics, Optical instruments

'High collection nonimaging optics' -- subject(s): Optical instruments

'Useful optics' -- subject(s): Optical instruments, Optics

'Aberrations of the symmetrical optical system' -- subject(s): Aberration, Design and construction, Geometrical optics, Optical instruments

According to the U.S. Census Bureau, there were at least 500 companies engaged in the manufacturing of optical instruments and lenses in the late 1990s.

Pantazis Mouroulis has written:

'Current developments in lens design and optical engineering IX' -- subject(s): Design and construction, Congresses, Optical instruments, Lenses, Imaging systems

'Current developments in lens design and optical engineering VIII' -- subject(s): Design and construction, Congresses, Optical instruments, Lenses, Imaging systems

'Current developments in lens design and optical engineering X' -- subject(s): Design and construction, Congresses, Optical instruments, Lenses, Imaging systems

'Geometrical optics and optical design' -- subject(s): Geometrical optics, Optical instruments, Design and construction