A large HD monitor for a programmer so that your eyes do not get tired?

Question

Monitors

I've been sitting on laptops for many years. The eyes are so accustomed to small monitors (13-15") that even after 8-12 hours of work there are no feelings of fatigue and problems.
The main programs that I use in my work are, of course, browsers, a development environment / code editor, and other tools A
friend brought a large 23" DELL S2318HN IPS monitor for testing.
Everything is great, a large screen, etc. - but my eyes get tired no matter how hard I try to get used to it.
I already changed the lighting in the office and moved it away and the contrast with the brightness twisted - I stopped at such indicators:

but still tired after 3-4 hours ... when you could sit at the laptop for 8-10 hours and no sensations - I already forgot what eye fatigue is .. .
A large monitor is convenient, it's great - but will your eyes really get tired on such a faster and there's nothing to be done?
I read somewhere that simple old TFTs (not IPS) are softer for the eyes? This is true?