After iOS 9.0 rolled out last year, Apple has just started distributing its biggest software update including the much anticipated Night Shift feature which doesn’t harm the user’s eyes at night.

With the software update, the Night Shift feature provides a reduced amount of blue light emitted by your display. The feature works similar to f.lux, which makes software for desktop, according to The Verge.

When it’s dark outside the colour display temperature changes and the warm temperature rises as the outside gets darker.

Users who received the update can find the settings for the Night Shift in the main settings app. Users can go to Settings —> Display & Brightness —> Night Shift  to control when you want the feature to start. Users can even manually adjust the colour temperature of the display with a slider.

As a default, the Night Shift is set for sunset and sunrise but users are also allowed to set their own custom schedule of when you want it to kick in by choosing the “From to” menu in the display settings. This option lets you choose the time you want it to start and end.

Users can also toggle the feature on and off quickly from the iOS Control Center. A new shortcut icon is also available to adjust the display temporarily when in need. For instance, users would be editing a photo.

It is difficult to explain how much of difference it makes by changing the lighting temperature for those who have never used f.lux or similar software. Of course, it reduces eye strain at night but it is also less disruptive for those around you when you are browsing at night.

Users who have been using the beta version for iOS 9.3 would know how the Night Shift feature works. It’s has made nighttime reading more enjoyable, notes Mashable.