Thanks all. What ambient light do you have/recommend?

We have potlights (2) above my computer but they are warm colours, unlike the massive colour-blast from the monitor. Lol.

I changed the Brightness to 45 and Contrast at default (50).  Looks much more usable now, despite a 5 unit decrease in brightness.  However, 100% scaling is crazy tiny, lol, it's nice during games but not on the Desktop (125% doesn't hurt my eyes).

I set my Acer G257HU 1440Hz IPS at 22% brightness and leave the contrast and gamma alone. I do photography and that brightness level gives me accurate tones and brightness when I print (meaning what I see on my screen is what prints) Plus, I take the extra step of calibrating my color with a Colormunki Smile.
 
I am also running Win 10 which comes with Dx12 (even though it's not optimized)

I've gotten used to it now. Sitting behind a TN monitor for a few years is like getting shell-shocked when you sit in front of an IPS screen. For games, I change the monitor profile to Normal (100% brightness) and use my custom User profile for other tasks.

NazcaC2
I've gotten used to it now. Sitting behind a TN monitor for a few years is like getting shell-shocked when you sit in front of an IPS screen. For games, I change the monitor profile to Normal (100% brightness) and use my custom User profile for other tasks.

Good to hear. I never crank up past the 22% although I might bump the gamma up a little. TN's tend to have the brightness cranked way up by default - almost painful sometimes, as you've learned.
 
Cheers

Actually, my previous TN monitor wasn't bright at all. The IPS monitor is really bright.