You may have read about 'Night Shift' in the last update of iOS. I just now tried it and it's pretty cool. In the evening the display goes from a bright white to a warm yellowish color. It is easier on the eyes. You might give it a try and see what you think. Jim Hamm
http://osxdaily.com/2016/04/07/enable-disable-night-shift-ios-control-center/