I recently was required to renew my glasses prescription because the other one was 2 years old (so considered expired). When I got my new prescription, my optometrist said "your vision improved". I have been spending more time outside. I have found that time on the water seems to make my vision improve. I also suspect that walking through forests and experiencing the parallax effect might function as something like a depth perception calibration. It's also worth noting that I do wear glasses, but not all the time - intentionally so I can exercise my eyes.