1) Lens 2) Lens system 3) Lense 4) Not astigmatic 5) Stigmatic 1) Stigmatic 
• (a.) 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.
Not astigmatic. ... (05 Mar 2000) ... 
An·as`tig·mat'ic adjective [ Prefix an- not + astigmatic .] (Optics) 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. 
Type: Term Pronunciation: an′as-tig-mat′ik Definitions: 1. Not astigmatic.
[adj] - pertaining to a lens or lens system free of astigmatism (able to form point images)
stigmatic adjective not astigmatic
(of a lens) not having astigmatism; forming point images of a point object located off the axis of the lens; stigmatic.