I too have been experiencing this eye strain and a headache since I started using my surface pro3 four days ago. I actually thought the device was too bright and reduced brightness to 35%, but the headache hasn't gone away. I really hate these so called "retina" devices. Was one of the reasons I stopped using the ipad 3 and iphone. My last device before the surface pro 3 was the Asus vivotab tf810C hybrid and that had the best screen at 600nit even though it wasn't high resolution just 1366x768. Would putting a matte finish screen protector be an alternative to cranking up the brightness to max? I'm kind of wary of that too.