I have been trying a used 2013 macbook pro retina 15in with dual cards (intel iris and nvidia 750m).
The first time I had it the eyestrain was really horrible. I checked the terminal and the display was from LG.
Since the used shop where I bought it has a really nice policy including returns, I told them about the eyestrain, they acknowledged it and offered to change the display to Samsung.
I must say the replacement did reduce the eyestrain quite significantly, although not getting rid of it completely.
I also run windows 10 build 1607 (pre-anniversary edition) on it. The eyestrain on that boot seemed quite bad, however turning off adaptive brightness helped again to get it to the same low level like the OS Sierra.
(a hint for windows anniversary eyestrain sufferers - doesnt the adaptive brightness turn on automatically with the update?)
Since the only change has been the display, I suppose Samsung either has PWM free displays or LG had really bad ones. I wanted to leave this here, since many people reported some Apple devices give them eyestrain while others do not.
Ill be happy to see if you have similar stories.