What is not astigmatic; --said esp. 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 called?

anastigmatic — Not astigmatic; --said esp. 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. (Webster's 1913.)

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