Auto brightness was great in iOS 7.0.3, went to Hades in 7.0.3, was finally perfect again in 7.1.2 Since then it has been steadily getting worse and worse (except a few versions of iOS 8 and 9 were fine briefly, then went bad again) as follows: At night the phone is my Nav on the dash. I turn brightness all the way down so as to not disturb my night vision. I pass under a streetlight and the auto-brightness pushes up screen brightness one or two notches. Then when it's dark again brightness stays up and will not go back down again. With iOS 10 it's the worst it has ever been because brightness gets kicked WAY up and never goes back down. Reset all settings and hard/factory resetting the phone doesn't work. This is software error that Apple fixes from time to time, but then somehow always seems to be reintroduced in a subsequent iOS version. I finally just gave the fick up two days ago, turned off auto-brightness, and I just adjust screen levels manually like back in my Android 1.x days. ETA: this is the case on an iPhone 5, a 5s, and a 6s+, so it's not a hardware issue.