I have the same problem when I'm in University and studied a lot. A trick I use is that when you take a break, don't look on your phone but instead go and open a window and stay in front of the window, even with the eyes closed if they hurt really bad, to relax your eyes. If they don't hurt that bad, looking outside the window, indentify the furthest away object and focus on it (this is a trick a doctor taught me). For me this did a sort of reset and after 5 minutes the pain in my eyes was significantly less and I could go back to studying.
One other trick is to use text to speech when you need to read something, for example an email, and you can look away while listening to protect your eyes as much as possible. This is especially useful if your job requires you to read a lot, like complaints, paperwork, maybe as a secretary, public servant. This of course won't work if you're a programmer or accountant, only for emails and such.
Minimize your screen time as much as possible, don't use your phone uselessly during your breaks or at home, and if you have to write messages to someone, it is better to call, or use a voice to text transcription on your devices so you don't keep your eyes as much on the screen when you have something to communicate.
Looking back at your message, you might have referred to something else rather than what I experienced with screen time, meaning eye pain without vision problems, but either way, I hope my message helps you minimize screen-time overall.