For weeks I was battling tension headaches. This seems to have helped alot:
On both my phone and my laptop, I turned on night mode (Twilight on my Android, f.lux on Windows) to run all day.
These apps are made to change the colors on your display, to filter out the blue light that wakes you up. It’s supposed to help with sleep if you’re a device user before bed. But I’ve noticed that filtering the blue light also helps relieve tension in my eyes. It has been about three weeks since activating the apps for the whole day, and I haven’t had a tension headache since.