I have experienced eye strain and blurred vision from using my new MacBook Air this past week for work. I can't focus properly on text, the letters go blurry and it stays with me for a while after using the laptop. I have had no issues like these with my (very) old 2010 MacBook Pro.
What I've done so far, going off what I read here and other places, is lowering the resolution (I could literally feel my eyes relaxing, but it could also be that I'm used to my old MBPs resolution), unchecking the "true tone" option in screen settings and also reduce transparency plus increase contrast. And obviously do all the right things that I do anyway (taking breaks etc).
Will give it some time to see if it helps things.