Using a computer screen in the evening could disrupt your sleep

For reasons that I can’t understand, some people refuse to believe that there is any connection between the light that hits our eyes and our moods and sleeping patterns. If you are one of those people then you may not get much from this blog. For the rest of us, there is a free piece of software called f.lux that might help.

f-lux-logoI discovered this software on a friend’s computer and decided to give it a go as I do often use a computer late into the evening and I do go through periods of not sleeping very deeply. Since it only takes two minutes to install the software I thought I’d try it. It’s been running on my main laptop for a couple of months now. I can’t prove that it’s actually helping me to sleep, but I can definitely say that it’s easier on the eyes when using the laptop in the evening (when the ambient light is much lower than during the day) and, coincidentally or not, I am going through a period of sleeping reasonably well.

The theory is that computer screens emit a light in a narrow waveband of blue that affects the production of a photopigment in the eyes called Melanopsin. Melanopsin is thought to be involved in the regulation of circadian rhythms. Using a computer in the evening might delay the onset of sleep by an hour or two and might affect the quality of the sleep. I’ve also found mention on a Wikipedia page that melanopsin may be implicated in the onset of migraine.

By the way, I often give links to Wikipedia pages in these blogs. The reason is fairly obvious – Wikipedia pages come to the top of Google search pages. I agree that we should always be wary of trusting what we read on Wikipedia, but they do provide a starting point and a springboard for further research if one feels inclined to pursue a topic. If you’d like a more authoritative starting-point for looking at the effect that LCD computer screens have, then check this link from the US Institutes of Health entitled “Evening exposure to a light-emitting diodes (LED)-backlit computer screen affects circadian physiology and cognitive performance“.

f-lux menu

The main options in f-lux

So, after installing f-lux, go into “Settings” to tell it your location (postcode) and it will then know when sunrise and sunset occur for you. During daylight hours your screen will look exactly the same as it does at the moment, but at night the screen will not emit most of the blue light that is associated with melanopsin. You can choose to have the software abruptly change the light that is displayed on your screen as it gets darker or lighter, or you can set it to gradually change over a 60 minute period. You can also choose just how much of the light spectrum is suppressed. There are times when you need to have your display showing normal, full-spectrum, colours (such as when editing photographs). The taskbar icon includes an option to turn off f-lux for a 60 minute period to cater for these situations. There is also an option to turn f-lux off for the remainder of the current night.

F-lux lighting levels

The lighting levels available on a PC.

I would recommend giving the software a trial of at least a few days. Initially, I kept finding that as the screen grew darker at around sunset I had an urge to turn it back up to normal. After a while, though, I got used to it to such an extent that the screen now seems to be painfully bright if I turn f-lux off for any reason during the hours of darkness.

F-lux is available for PCs, Macs, and Linux. The developers are working on a version for Android, but they don’t expect to release a version for “offical” IOS on iPads and iPhones (ie f-lux will not be available for IOS unless it is jailbroken).

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Computer Support in London
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