Even prescription glasses don't always correct astigmatism.... I thought my red-dot sights were fuzzy because they were cheap, until I saw the YouTube video and realised I had an astigmatism.
I had an eye test a few weeks ago as I thought my sight in my shooting (right) eye was deteriorating.
The local optician said my eyes hadn't changed, and when i mentioned astigmatism, he said i'd always had it...
I wasn't happy with that, so went to Vision Express and had another eye test... they said they could correct the astigmatism, and while testing my right eye diagnosed cataracts forming..
I eventually got the glasses from Vision Express... and my red-dots are still fuzzy...