Well instead of purchasing one more notebook with intel HD 4xxx I tried Acer Aspire E5-573-59GV with Intel Iris graphics.
What should I say?! It is better than the Intel HD 4xxx, but after some hours I get also the eyestrain. However it is a bit different. The eyestrain is not so strong and there is no pain behind the eyes and no headache and dizziness. It's just really really tired eyes. Maybe you can also try out and maybe we can get used to it because the issues are'nt so strong with the hd4xxx hardware.
I came up with the idea cause some people told in the apple eyestrain thread that they don't have any problems with new Macbook 12.
It's really much better, but it's not as comfortable as my old notebook. Maybe 4k is a good solution for us. What do you think?