Backlit e-readers 'damage sleep and health' • Hacker News Board

Re: Backlit e-readers 'damage sleep and health'

#41

Post by HackinOut » Tue, Dec 23, 2014, 9:23 AM UTC

eloisant wrote: post #36

HackinOut wrote: post #9

The well accepted definition of an e-reader is "a mobile electronic device that is designed primarily for the purpose of reading" (from wikipedia) and most (all?) of those devices are reflective as opposed to LCDs which are backlit. "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 withou…

There are a lot of e-book reader with a built-in backlight that can be turned on and off, like the Kindle Paperwhite. But I agree that using iPads then calling that "a backlit e-reader" is pretty stupid. That's a tablet.

Yes but they are totally usable with ambient light with the built-in light turned off as opposed to non-reflective LCDs. As a side-note, if I remember correctly, the built-in light in the Paperwhite is not a backlight but runs on top of the screen, thus using the reflective nature of the e-ink display.

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 :)

Re: Backlit e-readers 'damage sleep and health'

#42

Post by dang » Tue, Dec 23, 2014, 9:27 AM UTC

neindanke wrote: post #16

This article is poorly titled. Disappointing since the BBC is capable of better journalism than this. They should be specific that it is backlit LCD screens (especially LED backlights since their spectrum is predominantly in the blue range which simulates morning) rather than what is typically meant when someone says E-readers, ie: readers that use E-Ink panels which are not backlit and thus rely on ambient light.

We added "backlit" to the title to try to make it less misleading.

Re: Backlit e-readers 'damage sleep and health'

#43

Post by raverbashing » Tue, Dec 23, 2014, 9:30 AM UTC

paulannesley wrote: post #5

Probably the only useful line in the article: > 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, the point is moot.

It's a matter of intensity and spectrum, not if it's reflected or not.

Re: Backlit e-readers 'damage sleep and health'

#44

Post by HackinOut » Tue, Dec 23, 2014, 9:32 AM UTC

davedx wrote: post #37

eloisant wrote: post #36

Earlier quoted context omitted.

There are a lot of e-book reader with a built-in backlight that can be turned on and off, like the Kindle Paperwhite. But I agree that using iPads then calling that "a backlit e-reader" is pretty stupid. That's a tablet.

> There are a lot of e-book reader with a built-in backlight that can be turned on and off, like the Kindle Paperwhite. "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 t…

Thanks for the reference. I am not sure that backlights are the problem though. Just imagine shining a light behind the page of a book (although it's hardly comparable to the level of transparency of Liquid crystals). I would rather bet on the color of the light (warm vs cold). Maybe it's all in my head but when it's sleep time, I hate cold bulbs (and LCDs) while I am not bothered by warm light like a candle or a warm bulb.

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...

Re: Backlit e-readers 'damage sleep and health'

#45

Post by jonah » Tue, Dec 23, 2014, 9:40 AM UTC

veb wrote: post #19

jonah wrote: post #7

We just need f.lux[1] for our tablets. [1] https://justgetflux.com/

I hope you're not jesting, as this was my first thought. I definitely found it easier to fall asleep and stay asleep after installing Lux on my tablet, and phone. Flux for my computer. 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…

I am serious. Unfortunately, I don't believe Apple allows the necessary access to the graphics pipeline. :(

And yes, color is a big part of it. They have a whole section reviewing the research: https://justgetflux.com/research.html

Re: Backlit e-readers 'damage sleep and health'

#46

Post by jonah » Tue, Dec 23, 2014, 9:42 AM UTC

jkelsey wrote: post #26

lunarcave wrote: post #24

If you really have to read with a backlit display on your iPad or another device, just get flux[1]. [1] https://justgetflux.com/

Can't believe I have to jailbreak my phone to get f.lux on my phone. Love it on my Mac. Seems so obvious.

Lobby Apple.

Re: Backlit e-readers 'damage sleep and health'

#47

Post by seba_dos1 » Tue, Dec 23, 2014, 4:22 PM UTC

DrStalker wrote: post #34

ce4 wrote: post #30

Earlier quoted context omitted.

That's the same with smartphones and tablets. 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.

Are there any smartphones/tablets that have the light hit the display surface from the front and then bounce off like the kindle does? I thought they all either used a backlight shining through the display from behind or were an array of tiny little light sources (depending on the screen technology used) - either way the light is being broadcast direct from the source to your eyes; not hitting a surface and emitting…

Old monochrome reflective LCDs used that, but smartphones and tablets are almost always using transmitive screens with backlight (sometimes transflective, like on Nokia N900, but reflective properties are only usable in very bright sunlight).

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.

Re: Backlit e-readers 'damage sleep and health'

#48

Post by seba_dos1 » Tue, Dec 23, 2014, 4:24 PM UTC

SwellJoe wrote: post #31

hollerith wrote: post #10

Earlier quoted context omitted.

Since 2012, Amazon's high-end Kindles (the 2012 Paperwhite, the 2013 Paperwhite and the 2014 Voyage) shine light directly into the eyes. It looks just like a backlit display although technically the light and the diffusion panel are in front of an opaque (e-ink) display, not in back of a translucent (LC) display. On my Paperwhite, it is impossible to turn this light off -- only to dim it. Also, I dispute the OP's con…

I have a Paper White, as well. I can't imagine the light, when at its dimmest setting would be more trouble for sleep than any LCD thing. And, in fact, soon after I got a Nexus 7 and starting reading with it more often than my Kindle (using Twilight to redden and dim the screen dramatically and using the Kindle app in black background mode), my sleep schedule has kinda gone to hell. It's 3AM here, and I'm probably tw…

>I do wish it could turn off completely, however.

You can "jailbreak" it and simply control it via standard LED sysfs interface.

Re: Backlit e-readers 'damage sleep and health'

#49

Post by loco5niner » Tue, Dec 23, 2014, 5:47 PM UTC

hollerith wrote: post #14

superuser2 wrote: post #11

Earlier quoted context omitted.

The Paperwhite's LEDs front-light the display just like a reading lamp front-lights the pages of your book. It may look just like a backlit display, but the distinction is important.

Well, we'll just have to disagree on whether the distinction is important in the current conversation about effects on sleep. (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?

Rather than the source of the light shining directly into your eyes (iPad), in the Kindle paperwhite the light is directed onto the page, where it is diffused.

Check out the "light guide" description here:

http://www.nytimes.com/interactive/2012/12/26/technology/lig...

Re: Backlit e-readers 'damage sleep and health'

#50

Post by taurath » Wed, Dec 24, 2014, 7:37 AM UTC

Nemo157 wrote: post #6

taurath wrote: post #3

Earlier quoted context omitted.

Thats the primary reason I would buy a kindle over an iPad. Its not comparing e-readers and books, its comparing a bright screen with books.

The Kindle Paperwhite has a very blue tinted light. I'm not sure about other lighted eBooks, but I dislike that they specifically called out light emitting vs reflective surfaces. As far as I'm aware the colour of the light makes a much bigger difference to melatonin production than the source of the light. EDIT: Looking at the actual paper they were definitely aware of this with measurements of the colour spectrums…

Does it now?? Is there an option to go into standard e-ink/nonlighted mode? I've been considering purchasing one for a while in order to help my eyes at night.