Scientific study compares bedtime reading risk from iPad, iPhone, PW1
Oh, I’m very interested in your feedback on this one!
I’ve written many times about the difference between how a
or other frontlit device (the Voyage, and some other EBRs…E-Book Readers) versus how a backlit tablet, like the
or other backlit devices (the other Fires, a SmartPhone, a computer, a TV, and so on)
work, in terms of lighting.
On a backlit device, the lighting is behind the screen: what you see is between your eye and the light source.
On a frontlit device, the light is on the same side of the screen that you are. A light is pointed at the screen and bounces off…the same way that you can read when using a desk lamp, or the sun.
I find the Paperwhite and Voyage to be the most comfortable reading experience I’ve had…including paper.
A lot of people are concerned about how reading on a screen may be affecting their sleep habits. They have heard about “blue light” keeping them up at night, by messing with your biological system (perhaps they have heard that melatonin is involved).
I’ve always believed that the Paperwhite was not as bad…that reading on my Fire in bed would be more likely to keep me awake than reading on my Voyage.
Well, there’s now been a scientific study which produces some interesting and specific data…but I’m not sure I follow or agree with their conclusions:
Bigger, Brighter, Bluer-Better? Current light-emitting devices – adverse sleep properties and preventative strategies by Paul Gringras, Benita Middleton, Debra J. Skene, and Victoria L. Revell in Frontiers of Public Health
They tested the light emissions from an iPad, an iPhone, and a Paperwhite first gen. You can read the specifics of the models…I want to encourage you to look at the original report.
Here is a sort excerpt from the results:
“All the LE devices shared very similar enhanced short-wavelength peaks when displaying text. This included the output from the backlit Kindle Paperwhite device.”
That’s right: they found that the Paperwhite and the iPad had similar outputs in a measurement they suggested would negatively impact your sleep.
Many of the measurements they did were quite different for the iPad and the Paperwhite…about an order of magnitude (ten times) different. However, I guess those aren’t the wavelengths they consider impactful.
They also tested two remediation strategies: one hardware, one software.
The hardware one was for the user to wear goggles that filtered light.
The software one was to have the device go into a “sleep mode”, and shift the colors of the output.
Obviously, asking people to wear goggles to bed would not be an easy cultural shift. If we could get people to do that sort of thing, they’d be wearing helmets when driving their cars…that would save a lot of lives, from what I’ve heard. :)
The software fix makes more sense to me.
I love that the “nightstand” clock on my now discontinued Kindle Fire HDX 7″ has red numerals!
I have superior night vision, which may be connected to my color vision deficiency (“partial colorblindness”). When my Significant Other first met me, the light on my nightstand was a 25 watt red lightbulb…that was plenty for me.
So, I know I’m not typical. :)
I know, though, that a color shift could matter to even me as to how bright a light seems.
I have to say, my Voyage does not seem like it is keeping me up at all. I read a few “pages” in bed, and I’m ready for sleep…well, there is a big nighttime routine before that that is about half an hour, but the Voyage doesn’t seem to keep me up any more than a p-book (paperbook) did…less, I’d say.
My guess is that we may see a mode like this in the future, touted by the device manufacturers. There are all some things that do this, some settings on some computers, some apps.
My sense of the study is that their methodology for gathering the technical data was reasonable, for a small sample.
I’m not sure that that data does, though, cause the problems they suggest. I’d like to see studies with people actually using a frontlit device versus a backlit device and how it affected their sleep.
Oh, that’s one other thing: the study refers to something some of you already noticed…they say the Paperwhite is a backlit device, and it’s not. That doesn’t make me doubt their measurements, but does show a certain…lack of precision.
What do you think? Have you noticed any difference if you switched from a backlit device to a frontlit one when reading before going to sleep? How does it compare to reading with a nightstand light? If you do read the journal article, feel free to tell me and my readers what you think about it by commenting on this post.
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