I have ordered four pairs of -4 glasses from aliexpress ranging from 1 to 7 US dollars, from four various sellers, some have arrived already and are surprisingl

I have ordered four pairs of -4 glasses from aliexpress ranging from 1 to 7 US dollars, from four various sellers, some have arrived already and are surprisingly good, lenses are great really. Maybe I'm lucky to have standard distance between my eyes, but these super cheap glasses are just as good as those I used to buy in a local clinic for 50-100 USD.