If your iPhone is keeping you up at night, Apple thinks it has the solution. iOS 9.3 adds a new feature called Night Shift, which automatically adjusts the colors that your phone's screen emits. Once the sun sets, your iPhone shifts away from the brighter, bluer light it gives off during the day to a warmer palette.
The idea behind Night Shift is to reduce the amount of blue light emanating from your iPhone. That light can disrupt your sleep patterns by tricking your body into thinking its daylight, so that it stops produce the melatonin that helps you sleep.
The best thing about Night Shift: It does all the work for you, without making you remember to dim your screen. All you have to do is enable it. Here's how.
1. Go to Settings.
2. Tap Display & Brightness.
3. Tap Night Shift to turn on the feature.
4. Slide the Scheduled toggle to the right to turn on Night Shift. You also have the option to manually enable the setting until the next day.
5. To adjust the time when Night Shift adjusts your screen's color temperature, tap on the time. On the subsequent screen, you can customize the time Night Shift turns on and off; you can also set it to turn on automatically at sunset and turn off at sunrise, with both times based on your phone's location.
Note that not every device running iOS 9.3 supports Night Shift. For iPhones, the feature works with the iPhone 5s and later. On iPads, Night Shift works with all iPad Air and iPad Pro models, plus any iPad Mini from the iPad Mini 2 onward.