The American Heritage® Dictionary of the English Language, 4th Edition
n. An anastigmatic lens.
the GNU version of the Collaborative International Dictionary of English
n. compound lens or lens system designed to be free of astigmatism and able to form approximately point images.
The Century Dictionary and Cyclopedia
n. A system of lenses in which the astigmatic aberration is overcome and a flat field obtained.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. compound lens or lens system designed to be free of astigmatism and able to form approximately point images
Word Usage
"Both were fitted with anastigmat lenses, which eliminated distortion and preserved the perpendicular lines even of off-center images, making them especially well suited for architectural photography."