Glasses usually have obscene markups. Imo, the most cost effective way is often lasik (or similar), but it's an up front cost.
I think I paid 4k usd for both eyes, but that was something like 10 years ago and with no assistance from insurance.
I still get an eye exam every few years just to make sure everything is okay, but I am expecting another 10 years before I need too start thinking about vision correction again. Also, I'm fairly certain the provider that performed my lasik offered a warranty and would perform additional corrections as I age, but I don't live anywhere near the location anymore.
When I compare that to the combined cost of insurance, exams, glasses, contacts, and prescription sunglasses that my wife pays... lasik was a significant cost savings for me (and that's not counting any quality of life benefits).
And the more you dig into it, the worse it gets. That price discrepancy exists at the provider level too.
And it gets worse.
This video is a nice little primer about how the insurer might not even pay that $300 they agreed to, how that let's them profit further on the treatment while creating financial pressure on healthcare providers, and how your Dr may end up being owned by the insurer, further reducing the ability of a new co-op to compete.