I never use a screen after I go to bed, bedroom is pitch black and I just listen to audio tapes.
I take a walk first thing in the morning to allow my eyes time to "warm up", then only use a screen after I've come back. Callouts might force the use but they're usually over within 20 mins.
Always get my eye checked out at an optician every 12 months, always buy the best reading glasses I can afford.
If I'm not working and I start getting a headache from gaming or coding, screens off for a couple of hours, get some fresh air.
I use a screen calibrator for my monitors to get the right colour, contrast and brightness. Adjust brightness to be comformtable for the light in the room.