F.lux is an application that adapts the colour profile of your computer to the rising and setting of the sun.
Your computer screens produce white light, the same colour (albeit different intensity) as the sun. This is fine during the day – the colours look natural, but as the sun sets, should we really still be looking at the sun? This is essentially what we’re doing when we use our laptops, phones and tablets at night.
There’s a lot of scientific evidence that shows the effect of blue light on the body’s production of melatonin (the hormone that helps you sleep). I’m not going to go into detail about this, just know that blue light is not good for you if you’re trying to sleep.
This is where f.lux comes in. As the sun sets, the application changes the colour of your screen to match the colour produced by light bulbs instead of the sun. When the sun rises, the colours go back to normal. On first use, this makes the screen look orange and weird, but it’s not long before you get used to it and wonder how you ever lived without it. Seriously. Once you’ve used it for a few days, try disabling it. You’ll feel your eyes strain to adjust to the new colour.
Without f.lux, You don’t tend to notice that the screen is a completely different colour to its surroundings until you see it in a photo.
On the left is my laptop with f.lux disabled. The white of the screen is a completely different colour to the surroundings. Then with f.lux (right), the laptop’s colour is a more natural fit. It is more comfortable to look at for long periods.
Unfortunately f.lux is only supported on computers. On mobiles it’s a different story. The team at f.lux have made an app for iOS devices, but it only works on jailbroken ones. Apple don’t allow it on the app store because it requires access to settings which aren’t allowed to be accessed by apps. The thing is users can’t access these settings either. One of my friends has a jailbroken iPhone with f.lux installed and it looks beautiful at night. I want it, but I also don’t want to compromise the security and reliability of my iPhone.
I understand where Apple are coming from – I also don’t think f.lux should be in the app store – but instead it should be installed and enabled by default on all devices. It should be there as a setting right next to the brightness slider for everyone so that people who use their smartphones at night can get a better night’s sleep. The research supports it, f.lux users support it, it just makes sense. If a smartphone was released that natively automatically adapted its colour temperature as the sun set, I wouldn’t hesitate to buy it.
Download f.lux here (Windows, Mac, Linux):
Update: Apple have added a F.lux-like feature ‘Nightshift’ in their most recent iOS9.3 update