Apple iOS 9.3: New iPhone and iPad operating system has special light mode to help people sleep

The tool takes away the blue light at night, a change that studies have shown can help people go to sleep

Craig Federighi, Apple senior vice president of Software Engineering, speaks about iOS 9 during an Apple event (Justin Sullivan/Getty)

Apple has introduced a new feature intended to make it easier for people to sleep.

The next software update for iPhone and iPad will allow the devices to know when it is night time, and turn off the blue parts of the light coming from the screen — a change that Apple says makes it easier to sleep after using the screens in bed.

iOS 9.3 will use the device’s clock and location to work out when the sun is setting. Then it will shift the colours towards the warmer end of the light spectrum, making the screen easier on the eyes after the sunset and making it more like the ambient light.

The move follows recommendations from experts last year that tablets and phones should add a "bed mode" to allow people to sleep better.

Apple’s own page for the feature references the fact that “many studies have shown that exposure to bright blue light in the evening can affect your circadian rhythms and make it harder to fall asleep”.

In the morning, the screen moves back towards the blue end of the spectrum. That will mean that it could be unlikely that anyone will notice the feature, since it will move with the light coming from the sun.

The feature will arrive with iOS 9.3. That software has just been given to developers and those in Apple’s preview programme, and so will probably arrive on customers’ phones in the coming weeks.

The feature brings back some of the functionality that was previously offered by f.lux, which makes an app that changes the light settings on phones and computers. The company shut down the version for iOS in May, when it said that it had been contacted to say that the app — which was installed using a roundabout trick — was in violation of the terms of its developer program.

F.lux still offers a similar feature for Macs and Linux, where installing new software is easier and doesn’t need to go through the App Store.

iOS 9.3 brings a range of other improvements including the option to lock information in the Notes app so that it can only be accessed with a fingerprint, and new Health features that allow for extra information to be shown within that app.

It also brings new features especially for the iPad, such as an option for schools that allows different people to have their own logins. Some have predicted that could eventually roll out to the main consumer line of the iPad, allowing different people in one household to log on to a single device, a feature that has long existed in desktop computers.