Once you raise your arm for real, you don't really need to look at the target, your hand and hence pistol will be in the right spot.
All you need then is to fine-adjust the sight alignment, hence why you focus entirely on the front sight post.
Once you get good you just know how to stand and such, so you'll be mostly bang on right away.
For this reason, if you get glasses for shooting, you'll want them made so your best focus is at the front sight.
An optometrist cannot see through your eyes, so they use that lens comparing machine and ask you "which is better", and that leaves plenty of room for the patient to bias the results towards "different from normal is 'Better'", such that they vastly bias their new prescription upwards. Even if every optometrist is thinking about that and purposely downgrading the results of that flow, that could still provide room for the ratchet effect of eye prescriptions that many people with glasses have experienced.
Wearing glasses for 40 years and talking to ophthalmologists and optometrists.
Also I don't know where you are getting your glasses from, but where I am it's been decades now that the measuring of eyesight (with a machine) is done before the lens fitting, which mainly focuses on astigmatism.
I've been wearing glasses for myopia since I was ~10 years old and this is exactly opposite of my experience. Optometrists almost always prescribe the number slightly lower than they determine using tests.
When my number was constantly increasing, I remember ordering the next available increment just because the prescribed number was slightly annoying when looking at far away objects.
Now my number has been stable for a decade and I still sometimes get annoyed when using glasses at the prescribed power.
For baseball hitting, that would be a colossal advantage.
I might have better vision (with glasses) than a lot of people who wouldn't get glasses because their vision would be good enough.
I'm in Germany and my glasses are mainly used to correct my astigmatism.