Previous research had suggested that exposure to blue light, particularly from phone and TV screens, reduced the production of melatonin, the hormone that helps you to sleep. According to a study conducted by the University of Manchester, using night modes to make your display more ‘yellow’ is possibly worse than leaving it in the regular untinted mode. In fact, tinting your screen may actually be worse.

It turns out that blue light filter like Night Light - which tint the screen to reduce blue light and help users fall asleep - may not actually help users fall asleep.