Any opticians in this crowd ?

[Deschodt]

Quick Q on glasses, lenses specifically....

I've noticed on my last few pairs of glasses from "generic brand" opticians (maybe? aren't they all using random labs anyway?) some distorsion on the lenses... hard to explain... If I fix my eye on a spot and turn my head back and forth, the clarity of the correction will vary quite noticeably as my eye scans the entire surface of the lens from one edge to another...

In a side to side head motion looking at a fixed spot, the left edge of the glass is actually a tad better (more corrected than on center), then it gets so-so, then on center it's normal, then so-so again, then the right edge is **** (lot less correction)... [Edit: side note to Pelican, you allow PARF but the word **** (fecal matter) is too "out there" and needs editing?]

I get that you're probably supposed to rely on the center of the lens and turns your head and not just your eyes, but I find it odd that previous pairs of glasses from independant opticians - not chains, not as quick - did not exhibit this variation (MOL same prescription for nearsightedness) and seemed to be consistent throughout... just wondering if it's a quality thing or if I just never noticed before, if my expectations are too high or if I should be asking fo ra specific type of lense to avoid this ?

I did not get el-cheapo lenses either, $350 or so just for lenses, but maybe there are better labs or better lenses out there ? Anyone in the field care to elaborate and educate me ?