Anastigmatic adj. (Optics) Not astigmatic; free of astigmatism; pertaining to a lens or lens system, and used especially of a lens system which consists of a converging lens and a diverging lens of equal and opposite astigmatism but different focal lengths, and sensibly free from astigmatism.
... correspond to one object plane; and these are in contact at the axis point; on the one lie the focal lines of the first kind, on the other those of the second. Systems in which the two astigmatic surfaces coincide are termed anastigmatic or ... — Project Gutenberg Encyclopedia
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