My eye doctor told me to follow the 20-20-20 rule, and it changed everything. I used to power through like you, but my eyes would get so tired lol. Now I look at something 20 feet away for 20 seconds every 20 minutes. It lets your eye muscles relax, so when you go back to work, you see details better. My accuracy went up a ton, and I don't get headaches anymore. Seriously, try setting a phone timer, it's a game changer.
Have you seen those articles about how our eyes dry out from too much screen time? I read that the 20-20-20 rule actually helps you blink more often, which keeps your eyes from getting so gritty. It makes sense why your accuracy improved, since dry eyes can mess with your focus. I should really try the timer thing, because I always forget to take breaks. Maybe it's time to stop ignoring all those health tips, right?