Hi - brand new user member here!
For those trying out new macbooks, please note that Apple frequently uses PWM to dim the keyboard!
I am typing this on a 2013 MacBook Pro that I had my wife use for years because I was getting headaches. I turned off keyboard backlighting and I can now use it without trouble!
So, if you have some trouble with eye strain on Apple laptops, I think it would be worth turning keyboard backlighting off before you conclude you have to return it.
Tait