If I may ask, where did you get your vision checked for the prescription? I think I'm going your cheap route, however, my vision insurance has long been cancelled since I turned into a contractor..
I have insurance with a vision plan, however when I bought glasses from Zenni I used an old prescription from 8 years ago. My vision hasn't changed significantly in my adult life. I do still go for an eye exam every couple of years, mainly to keep an eye out for glaucoma, which may run in my family a bit.
The last time I got my eyes checked, I went to a Lens Crafters type store that was having a special for an eye exam and 2 pairs of glasses for $99. Of course they tried to upsell me on the lenses and frames, which got expensive quickly, but I declined and just got the bare minimum. Then I bought a pair of glasses with a nicer lens material online at Zenni. So now I have a few pairs of backup glasses, which is very nice.