martin
I had the same issue with a desktop HP (Nvidia GeForce 1050). Initially the box shipped with Win 10 that when i connected to my trusted CCFL display it caused me severe headache, no eye strain just an unbearable headache (my eyes were fine!!!!). Installed Win 7 and Ubuntu 16.04 LTS, same issues.
What seem to have worked though was Lubuntu 16.04 LTS. The system is still not perfect, i still get some mild headaches if i don't take breaks, but it is usable. Unfortunately i need Windows to install accounting packages so Lubuntu is not a choice.
The reason i installed Lubuntu in the first place, is that in the past a Dell laptop with Win Vista that i switched to Ubuntu caused me migraines after the switch. When I installed Lubuntu (the reason was that the laptop was slow with Ubuntu anyway) the migraines disappeared and the now the display is perfect.
For me up to now it all boils down to software. I think led lights could be handled with lenses since they block the excessive blue light. I do it with Crizal lenses and it seems fine. But with software i feel helpless.