I don't have a desk job. 🤷🏻♂️
I also always end up taking a break in the suggested (or rather, the suggested manner back when video games straight up had warnings about playing too long in the manual/splash screens when starting them) when I am playing. Just stand up, walk to the kitchen/bathroom/whatever and look at something other than a screen for like 5-10 minutes every 45-minutes to an hour.
You should be able to do that at work, too. Just stand up, stretch, look at the ceiling/floor. You don't even have to leave your cubicle/office.