Astigmatism. The correction that is exceedingly rare in actual necessity. Yes, you probably didn’t actually have astigmatism the first time they gave you glasses with correction for it. Surprised? Incredulous? Not sure what to think?
Browse this section for science about astigmatism, how-to guides, and a whole lot of students who successfully reversed their lens-induced astigmatism. Odds are you won’t need this complex focal plane correction for long!