In what should come as a surprise to no one, it turns out just making your smartphone's screen kind of yellow may not stop it from keeping you awake. In fact, according to a study out of the University of Manchester, that yellow-shifted "night light" is even worse for helping you get to sleep than just leaving your phone in the standard untinted mode.

The reasoning behind using a yellow tint on your screen was, at least, based on scientifically plausible principles. In your eye, a protein called melanopsin responds to the intensity of light, and specifically, it responds more strongly to light of a shorter wavelength.

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