In the world where custom rom developers do wonders, I am baffled by how lazily samsung is taking this up... I'm dying out here from headaches.
If you go to https://ledstrain.org/ you will find 100's of people struggling with newer displays in phones and computers. Most have tried every option in the phone to help. Some even visiting specialist doctors only to be told there's no issues with their eyes. They are all stuck using 5-10 year old devices that give them no eye issue. Something in newer devices is causing this. The forum has a lot of information, even going into technical depth about the new screen tech.
Few of us know the cause of blurred vision, so Samsung will never develop improvements that cost the company. We have to wait for it to become more common or just change brands. You also have to be careful on the screens, many have slow pwm. They should at least have the decency to notify the buyer
Having the same exact issue with the current S21 ultra. Upgraded from a Note 8 (that I LOVED and had for 5 years). I have never experienced so much eye strain from a phone before. I have daily tension headaches, migraines, and motion sickness. I have tried everything from reducing the refresh rate, upping the eye comfort filter, maxing out brightness and using a 3rd party dimmer, nothing is helping! I'm trying a few more fixes and if there's no improvement, I'll be going back to a Note 8. So disappointing and a waste of $1000.