Backlit e-readers 'damage sleep and health'
bbc.co.uk
bbc.co.uk
"They spent five days reading from a paperback and five days from an iPad.". If only iPads were used, I don't believe the word e-reader is appropriate.
If you use an e-ink display without a built-in light, there are no reason this would be any different then using a book (as mentioned in the article but it's not only about "the original kindle"). Also there were tons of studies about the effect of light on sleep and especially blue light emitted by LCDs, most e-reader makers use a warmer light if I'm not mistaken.
EDIT: elaborating
But I agree that using iPads then calling that "a backlit e-reader" is pretty stupid. That's a tablet.
"Paperwhite guides light toward the surface of the display with its built-in front light—unlike back-lit tablets that shine in your eyes" [1]
I have a Kindle Paperwhite, and was surprised to read this article, because I have no trouble sleeping. Apparently the way the light works is the reason for this :)
[1] http://www.amazon.com/Kindle-Paperwhite-Ereader/dp/B00AWH595...
Furthermore, it seems to me that with the Paper White's light guided "on the surface of the display", the light shines as much in towards your eyes as it does towards the screen...
EDIT: I probably should have said "without the built-in light" but wanted to include devices that do not have one to begin with. I am still using one of these :)
> The light emitted by most e-readers is shining directly into the eyes of the reader, whereas from a printed book or the original Kindle, the reader is only exposed to reflected light from the pages of the book.
So it's talking entirely about brightly backlit tablets, not e-readers with e-ink.
Also, I dispute the OP's contention that reflected light on s paper book is any better; certainly, a normal bed-side lamp is worse for the sleep of anyone sharing the room with the reader.
EDIT. Although like I just said, an iPad probably has less of a deleterious effect on sleep than a Kindle Paperwhite does, it is probably possible to do better in the current market. Specifically, Samsung makes a tablet (the Tab S, which comes in 10.5- and 8.4-inch versions) with an OLED display, which has the advantage over LCD displays that the portions of the screen that are supposed to be black do not emit any light at all. Especially if used with software that displays red or orange text on a black background (to minimize the blue-ish photons) an OLED display is the best choice in the current smartphone-plus-tablet market AFAICT if protection of sleep is the main consideration.
EDIT. Oops, I forgot to include my main reason for preferring the iPad to the Paperwhite: on iOS, Settings > Accessibility > Invert Colors reverses black and white. Combined with the fact that many iOS apps like Safari and iBooks normally present a white field broken only by text and thin lines, the use of "Invert colors" probably results in less light entering the eye than a Paperwhite since (unless they changed it since I last updated the software on my Paperwithe a couple of months ago) you cannot alter the Paperwhite's default color scheme of black text on a white background. I will concede that the Paperwhite's brightness setting goes a lot dimmer than the iPad's does, but I consider that consideration to be trumped by what I just wrote, and, again, neither Paperwhite nor iPad comes close IMHO to an OLED display used with decent software.
(Kindle paperwhite owner and frequent iPad user here.)
What is it about the photons entering the eye that you imagine makes the "frontlit" display of the Paperwhite better than a backlit LCD display?
Check out the "light guide" description here:
http://www.nytimes.com/interactive/2012/12/26/technology/lig...
The LEDs in the Paperwhite Kindles do not shine light directly in the eyes: the leds shine from below the screen towards the top end of the screen. As it exits the LEDs, light is reflected inside a light guide from which it exits towards the display from specific holes, much like a leaky fiberoptic cable[1].
The directionality and position of the LEDs, and the existence of the light guide, are precisely the differences which make the Paperwhite unlike a backlit display.
[1] http://www.nytimes.com/interactive/2012/12/26/technology/lig...
For the sake of simplicity and to keep it as thin as possible, they use edge-LED lighting with a diffusor layer to spread the light evenly.
Kindle Paperwhite however has 100% reflective e-ink screen plus set of LCDs that shine through the light guide layer above the screen. Some people think that makes it better than transmissive LCDs - that's why using Kindle Paperwhite instead of iPad in this test would be much more insightful, as sleep-disturbing properties of transmissive, blue-tinted LCDs are nothing that wasn't known before.
uh, how so? You didn't give an argument for this point. At the very least Kindles go far dimmer than iPads do.
For reference for those who don't have a Paper White; when at its dimmest setting, it is probably less than the ambient light in the room from neighbors porch lights and street lights. It is almost completely dark, and looks like an older non-lit Kindle in any room with lights on. I do wish it could turn off completely, however.
You can "jailbreak" it and simply control it via standard LED sysfs interface.
It's a matter of intensity and spectrum, not if it's reflected or not.
https://justgetflux.com/research.html http://www.pnas.org/content/early/2014/12/18/1418490112.full...
I was really hoping for research comparing F.lux to a non-backlit screen; this seems to tell us what we already knew.
I guess we'll have to wait for more detailed studies.
To further reduce light exposure I use gray (remapped to yellow) text on a black background (very dark because the display is OLED). I set the screen brightness to maximum in FBReader to avoid PWM flicker, and reduce the text brightness to compensate. I also disable the phone indicator LEDs. I don't find reading like this to harm my sleep.
The one problem is that the mDNIe mode very briefly flashes to default when the phone is first turned on from standby. I think this could be fixed with a kernel patch but I just avoid looking at the screen then.
I also ordered an amber filter for my phone, although I think perhaps a better solution would be to not use phones/tablets in bed.. but I'm not sure it's realistic to always avoid the temptation.
The final part of the solution is to have a wake-up light. I had one before, and it's really quite essential up here in the north. But I think it would be beneficial everywhere. Studies showed that people have different times it's natural for them to wake up ("A" and "B" people), and if you wake up earlier than what's natural for you, it affects your performance. Solution? Block out all external light from the bedroom, and use a wake-up light as an artificial sunrise. (Or allow people to come to work/school at different times, but that's not always an option).
EDIT: Looking at the actual paper they were definitely aware of this with measurements of the colour spectrums of different tablets, unfortunately not including the Paperwhite. Disappointing journalism skewing the story as normal.
* https://play.google.com/store/apps/details?id=com.vito.lux&h...
1: https://play.google.com/store/apps/details?id=com.urbandroid...
If I disabled Flux -- like I just did -- it's awfully painful! Torture! How did I used to stare at this awfully lit thing for hours on end and expect sleep to be peaceful?!
On a serious note, it'd be interesting to see whether it's the actual 'light exposure' that's hindering the sleeping process, or the 'blue light' that Flux, Lux and others have set out to solve.
And yes, color is a big part of it. They have a whole section reviewing the research: https://justgetflux.com/research.html
1. http://www.amazon.com/Uvex-S0360X-Ultra-spec-SCT-Orange-Anti...
If you look at the progression of artificial lighting, from candles, to incandescent, to halogen incandescent, to fluorescent, to LED, each generation typically increases both the blue light production and the brightness. Such strongly blue spectrum isn't an essential feature of the technology, so I suspect that it's marketing driven because it looks more futuristic.
Additionally, a lot of LED lighting flickers at frequencies that are visible when you move your eyes via the phantom array effect: https://en.wikipedia.org/wiki/Flicker_fusion_threshold#Visua... I personally find this very annoying, but even if you don't consciously notice this it's something not found in nature, and I'm not aware of any long term safety studies.
I'm very skeptical of these changes. Humans have a poor track record of predicting safety implications of new technology (eg. radioactive materials as health products, leaded gasoline, etc).