new cell phone-should I go 5.5" screen or bigger?

I've been getting headaches whenever I read stuff on my phone (currently on a 5.2" screen). I'm pretty sure its due to the size of the screen as I do not get headaches when using my ipad mini. I also got headaches when reading my old phone (5" screen)

when I read my phone in landscape it helps with the headache, but I cant stand not having more of the webpage in front of me without scrolling.

just curious if anyone else had this problem and had success switching to particular screen size