E-readers 'damage sleep and health,' doctors warn

[bounce]

Blue light is the issue I have with the lighted Kindles. The strange blue tint of the screen coupled with a light disrupts circadian rhythm/melatonin to some degree. I'd buy a Voyage or Paperwhite again if I could completely shut the light off.

This isn't just anecdotal, there are countless abstracts on Pubmed published about this.

[DuckieTigger]

Originally Posted by Shades

Something like this?



With brightness set very low, this looks very good at night.

Yes, exactly like that. Except I cannot dim your picture down enough on my tablet to reach my reading level - that is why I chose to use a darker red (about 50% red, instead of 100%).

Edit: I see that your red is not full 100% (still too bright on my tablet), and it will depend on your own control mechanisms for brightness - I don't use any screen dim apps, just builtin. FWIW, fbreader does not go as dim as the system brightness slider, so I disabled the left side light adjustment option.

[DuckieTigger]

Originally Posted by bounce

Blue light is the issue I have with the lighted Kindles. The strange blue tint of the screen coupled with a light disrupts circadian rhythm/melatonin to some degree. I'd buy a Voyage or Paperwhite again if I could completely shut the light off.

This isn't just anecdotal, there are countless abstracts on Pubmed published about this.

As for Voyage and Paperwhite, you also got to remember that Amazon does not recommend reading them in total darkness. If you want to turn the light off and then turn a bedside lamp back on, I would say to just leave the light on the lowest setting and then turn the extra light on if you are worried about the blue tint. Reading in general in total darkness with only the book lit up is not good advice.

[twowheels]

Originally Posted by DuckieTigger

As for Voyage and Paperwhite, you also got to remember that Amazon does not recommend reading them in total darkness.

First I've heard this. Where do they recommend against that?

[JSWolf]

Originally Posted by twowheels

First I've heard this. Where do they recommend against that?

I've been reading in bed in the dark at 4 - 6% brightness and I've not had a problem.

I too would like to see where Amazon gives this bad information.

[wodin]

What none of the abstracts that I've read addressed was the type of light used to read the non LE control devices or paper. In today's world of low energy light bulbs, CFL's by definition produce UV light which is then converted by a fluorescent coating into visible light. The problem is the fluorescent coating does not filter all of the short wavelengths and produces much more blue light than an incandescent bulb, or even some colors of LEDs.

Any time I see an incomplete study like this I immediately start looking for an agenda.

[DuckieTigger]

Originally Posted by twowheels

First I've heard this. Where do they recommend against that?

For the Voyage they used to say it is perfect to read in the dark. There came complaints in with some that have medical problems - and they all of a sudden changed both Paperwhite and Voyage to be suiteable for dim environments instead.

Coincidence? No I don't think so. You won't find evidence on current pages about the readers beeing ok in total darkness.

Edit: current pages mentioned is not correct any more - see next post.

[ApK]

Originally Posted by DuckieTigger

For the Voyage they used to say it is perfect to read in the dark. There came complaints in with some that have medical problems - and they all of a sudden changed both Paperwhite and Voyage to be suiteable for dim environments instead.

Coincidence? No I don't think so. You won't find evidence on current pages about the readers beeing ok in total darkness.

This is incorrect. You're reading way too much into a piece of marketing copy.
The pages and search results for both devices still refer to reading in the dark.

"Kindle Voyage can be read in bright sunlight or total darkness—and it's smart enough to know the difference."

"When reading in the dark, the adaptive front light slowly lowers the display's brightness over time to match the way the eye responds to darkness."

"Adjust your screen's brightness for great reading in any light"

[DuckieTigger]

Originally Posted by ApK

This is incorrect. You're reading way too much into a piece of marketing copy.
The pages and search results for both devices still refer to reading in the dark.

Ah, I see. Now they are targeting specifically backlit tablets:

Won't tire your eyes in the dark

Paperwhite guides light toward the surface of the display with its built-in front light—unlike back-lit tablets that shine in your eyes—so you can read comfortably without eyestrain

I guess they will always make their advertisements on the safe side. And nothing can be interpreted into them unless they say not to do something for this or that reason.

[SteveEisenberg]

Originally Posted by GoSharks

No, @arjaybe just said that replicating real world conditions "would be an untenable restriction to impose on experimenters"...which is an even bigger laugher.

Except that real world conditions would result in a meaningless uncontrolled muddle AKA an even bigger than bigger laugher.

For a real world study, there needs to be a preliminary study of real world use. Consider that a majority of posters on this thread think the great majority of tablet users turn down the light intensity at night, but a minority, including myself, think most do not. Since majority doesn't rule on factual questions, the researcher would have to study this first.

After the preliminary study was used as the basis for another sleep study, variables such as ambient room lighting and reading time would no longer be controlled. That's because, in the real world, people who read on different devices are different in their reading habits in other ways. There would then be no basis to say which variable caused any difference in sleepiness.

Most likely, average ambient room lighting used with tablets is different from than that used with eInk is different from that used for paper books. So you then, in a real world study, couldn't say whether the effect was due to the device or the ambient light.

Another real world difference is that people who use tablets switch back and forth between reading, web surfing, gaming, etc. Book and eInk readers rarely surf on their device. They just read*. And they may use their device (considering here that a paper book is also a sort of device) for a shorter period of time because it is more limited. On the other hand, paper book readers may watch more television. Or less. I don't know. I do know that there is a heck of a lot of difference, in the real world, in how people use screens depending on their chosen device.

You can have real world, and you can have controlled experimentation. You can't have them both.

One corollary of this is that every study has strengths and weaknesses. Controls and real-world are both virtues, but the more you control, the less the experiment is real world.

This issue is not limited to sleep medicine. Real world medical practice, vs. controlling as many variables as possible, is, or should be, considered, and even agonized over, in design of most drug studies.

Some experiments are better than others. One reason the study under discussion is better than most is the careful control of variables so that the only difference between the two groups is the reading device. Is that real world? No. Does it tell us something real about the effects of different reading technology? Absolutely.

_____________________
* I use the Kindle Keyboard web interface a lot. But this is atypical.

[meeera]

Originally Posted by SteveEisenberg

For a real world study, there needs to be a preliminary study of real world use. Consider that a majority of posters on this thread think the great majority of tablet users turn down the light intensity at night, but a minority, including myself, think most do not.

Whether or not most people make a point of reducing brightness in dim light, the iPad does it by default. You have to go out of your way to disable auto-dim in order to get this experiment's conditions.

[SteveEisenberg]

Originally Posted by meeera

Whether or not most people make a point of reducing brightness in dim light, the iPad does it by default.

This keeps on getting repeated -- that the ambient light was dim. Yes, that's how the researchers categorized it. But they also gave numbers to the ambient light, and I don't think the average person would describe that as dim. I don't say that because I am familiar with the numbering system used there. I'm not. I say it because a dozen people were able to read paper books in that light for two hours straight (before the break). The study subjects wouldn't have done that if it was what a layman, as opposed to a sleep medicine physician, calls dim.

As for whether the stated lighting is what the Apple programmer for that iPad feature considered dim, I don't know. But I've read all the posts in this thread, and no one who has that iPad has done the experiment at home (admittedly some work as you need a cool white fluorescent, while most people probably have, at home, if they have any fluorescent fixture, warm white). Instead posters make the claim, without any evidence, that the stated iPad brightness is way lower than real life.

I do note and appreciate that, at the time you are criticizing the study, you, unlike some others here, don't claim the researchers are stupid or malign.

It is quite possible that if the light coming out of the iPad was dimmer, the result would have less strong. Maybe the results -- really quite strong for such a small sample -- would no longer have been statistically significant. But it's implausible to me that, with a less bright setting at the same wavelength, and a larger sample, the results wouldn't go in the same direction.

[GoSharks]

Originally Posted by SteveEisenberg

You can have real world, and you can have controlled experimentation. You can't have them both.

This is where we will have to politely agree to disagree. Designing an experiment to mimic real world conditions and yet to be able to adjust single variables is the Holy Grail of experimentation. It may be difficult and at times may require multiple attempts from different directions to acquire useful data, but it is what researchers strive to accomplish. It is why 'good' experiments take more sweat and effort to design then they do to perform. If you abrogate all obligation for the thoughtful design of an experiment because you advocate the essence of Chaos Theory, then you are throwing darts with your eyes closed and hoping to hit something...if you do, it is pure luck and not by design.

[meeera]

Originally Posted by SteveEisenberg

This keeps on getting repeated -- that the ambient light was dim. Yes, that's how the researchers categorized it. But they also gave numbers to the ambient light, and I don't think the average person would describe that as dim. I don't say that because I am familiar with the numbering system used there. I'm not. I say it because a dozen people were able to read paper books in that light for two hours straight (before the break). The study subjects wouldn't have done that if it was what a layman, as opposed to a sleep medicine physician, calls dim.

The iPad does not default to fixed full brightness in evening indoor conditions where there is ambient lighting, low but bright enough to read paper books. It just doesn't. Try it. Then put it on full brightness in those conditions, with a black-on-white book showing, one foot from your eyes. It is like looking at a blazing sun.

RIGHT NOW I am in indoor midsummer daylight, far brighter than a lamplit evening room that I would read pbooks in. My iPad is right next to me, well-lit and very easy to read - a little too bright for my liking, to be honest, once I go into the settings area which has a grey/white background. The brightness setting is well under halfway. This is what happens in the real world.

[jbjb]

Originally Posted by SteveEisenberg

One reason the study under discussion is better than most is the careful control of variables so that the only difference between the two groups is the reading device.

Except that's not the only difference. The experimenters imposed different physical arrangements on the two groups, in that the iPads were held in a stand in a fixed position, at a fixed distance from the subject, and the subjects were not allowed to hold them, or adjust the position. The paper book readers had no such constraints. I don't know about you, but reading for hours in a fixed position is something I'd find physically very uncomfortable, and it could easily skew the experiment.

/JB