Hi, I bought Macbook 12 (2015) after about 3 years using of Macbook Pro 15 Retina. I never had a problem with eye strain and pain with this Macbook Pro. Retina is great and I cannot imagine my work without it. Now I use Macbook 12 - smaller screen but same font size, same brightness. I see everything perfect but after few hours I have eye strain and pain like never before. Have you same experience or do you know where is problem? Thank you.