I have an astigmatism in my right, or dominant eye, or so they say. Up until about 10 years ago, I wore progressive trifocals, which every other year or so, they would increase the power of.
One summer back then at work, I broke my glasses, and could not get to the eye doctors to replace them, so I started to just wear my safety glasses. I havent worn corrective lenses since, and believe it or dont, my eyes have actually gotten better, not worse. At this point, I use Walmart 1.5x "3 pairs for $7" cheaters for reading very fine print on blueprints, script bottles, etc. Other than that, I dont need them, and havent missed them in the least.
My theory is, every time you go in, they increase the power, and it just makes your eyes progressively weaker, lazy. Ive had three eye exams since, and every time, asked the doc about my theory, and they all just blew me off and didnt seem to want to hear it. This past summer, I took my 10 year old glasses along to a different doctor, and didnt say anything until after the check up, and then gave him the glasses. He did admit, while still not perfect, my eyes were better than those glasses would have suggested. He still didnt want to hear it though. I do still have an astigmatism apparently.
Im not saying some people dont need them, far from it, just that I do think its a big racket, and sort of a sure thing for the eye glass places.
All that said, Ive used red dots now for about 15 years, with and without the glasses, and I see no difference. The dots have never been "round", but they are not some big starburst thing either. The dot looks the same to both eyes too, and my left eye doesnt have it, so I dont know whats up with that. I dont have, nor have I ever had, any issues with scopes either.