Apart from what everyone else said (go see an ophthalmologist ASAP, eyes change, and wear your glasses), I've found that e-ink screens drastically reduce eye st

Apart from what everyone else said (go see an ophthalmologist ASAP, eyes change, and wear your glasses), I've found that e-ink screens drastically reduce eye strain for me (as in, I cannot stand a normal screen for more than a few minutes, my phone's OLED tires me within tens of minutes at a time, but i can spend the whole day on my Kindle or e-ink tablet). Check if that's the case for you too with a low cost option (like a Kindle), and if it works it might be worth investing in an e-ink monitor (which doesn't work for everything but should be fine for coding).