anastigmatic vs anastigmat

anastigmatic is not a noun while anastigmat is a noun.

Word	Noun	Adjective	Verb	Adverb
anastigmatic	No	Yes	No	No
anastigmat	Yes	No	No	No

anastigmatic (noun)	anastigmat (noun)
	compound lens or lens system designed to be free of astigmatism and able to form approximately point images

anastigmatic (adjective)	anastigmat (adjective)
not astigmatic
pertaining to a lens or lens system free of astigmatism (able to form point images)