Eye strain from monitor: what am I doing wrong?

I’ve been dealing with serious eye strain lately and can’t seem to figure out what’s causing it, hoping someone here has been through this.

My setup: I use a Studio Display. My desk is right next to a window so I get plenty of natural light during the day, but the glare is so bad I usually have to pull the curtains anyway. I also tend to work late into the night pretty regularly.

Symptoms: by the end of a long session my eyes really hurt, and sometimes the text even starts to blur a bit.

Things I’m wondering about:

• Should I be adjusting True Tone / brightness differently for night vs. day?
• Is Night Shift or a third-party app like f.lux actually worth it?
• Any tips specifically for late-night work?

I’ve tried bumping up the font size a little but haven’t made any other changes. Would love to hear what’s worked for you, like monitor settings, lighting setups, habits, eye drops, anything.