I never had any issues before with eye strain until I started using my new macbook pro. I immediately noticed something was off, but kept using it for a few hours until it became unbearable. My eyes became extremely light sensitive and I used night shift and the flux app, which ameliorated my condition a bit. But it seemed within a few minutes, my eyes would become uncomfortable again, and I would have to redshift the screen even more to make my eyes stop hurting. This process continued until I was all the way in the halogen end of the spectrum.
At some point, I realized that my issue was only with reading the text on screen and I had no issue with video.
Basically, my eyes were unable to focus on the macbook's anti-aliased font and everything I was reading had this weird 3D optical illusion type aura to it. I think this caused my pupils to continue to dilate in vain to focus on the text which is why I became so light sensitive.
In any case, for me the light sensitivity was all a red herring caused by the anti-aliased text and turning font smoothing off in System Preferences solved the issue for me. Just wanted to get this out there in case anyone is suffering from the same thing since the fix is so simple.