It's not just that there is too much white space in IOS 7 but something about the color itself. Very fatiguing to the eyes, causes irritability, and ruins the crispness of the fonts. After a day, I went back to 6.1 on both iPad4 and iphone5 and it made a tremendous difference. Get back while you can. The light ruins anything that runs on top of it -- even turning the intensity down very low didn't help. As more people realize this, it is going to be a major drawback to IOS 7. Someone who knows what they are doing should investigate to see which 'color' white Apple is using.