6 ms·

Evening use of light-emitting eReaders negatively affects sleep (2014)

33 points by ivanvas 5y ago

mekkkkkk 5y ago
I wonder if the type of illumination used for traditional book reading is relevant. I.e. would a bedside lamp with cold light provoke the same effects?
- zachruss92 5y ago
  From my understanding from what experts say any light will affect your sleep to some extent. The big issue with backlit screens are that the blue lights are projected directly into your eyes which compounds the effects as more photons hit your eyes.
  - mekkkkkk 5y ago
    Is that true though? I was under the impression that two surfaces with the same perceived brightness would bombard your eyeballs with the same amount of photons. Regardless of whether or not the surface is emitting or reflecting light. On the other hand, maybe there is some filtering taking place when light is bounced off materials. I.e. blue wavelengths being absorbed by the paper.
  - bXVsbGVy 5y ago
    This is both correct and wrong. Some lights affected more than others. A paper[1] funded by NIH published this year showed that ~12 log photons cm⁻² s⁻¹ on λ=460nm is enough to suppress melantonin production. I've discussed more on sibling thread. [1] https://journals.sagepub.com/doi/pdf/10.1177/0748730415585413 https://journals.sagepub.com/doi/pdf/10.1177/074873041558541...
- nicoburns 5y ago
  > would a bedside lamp with cold light provoke the same effects Almost certainly from my own anecdotal experience. There's a reason why bedroom lights tend to be warm (even though they're often now leds)
- bXVsbGVy 5y ago
  I spent the past weekend reading papers of blue light effects on melatonin suppression to decided if blue light blocking glass was supperted by science, and to know and to know the parameters I should consider. As today, the academic consensus is that Melatonin suppression, on the lower part of the spectrum, is regulated by melanopsin produced by the Intrinsically photosensitive retinal ganglion cells (ipRGCs) -- not blue rods. The photosensitivity of ipRGCs has λ_peek = ~460 (nm). They've done experiments with rats without cones and rods (but with ipRCS), and they displayed circadian cycles. Melatonin is also suppressed by lights on higher part of the spectrum, but haven't papers on it. I've decided in getting this safety glass: https://www.thorlabs.com/thorproduct.cfm?partnumber=LG3A https://www.thorlabs.com/thorproduct.cfm?partnumber=LG3A The dark amber glass from swanwick have similar optical density curve: https://www.swanwicksleep.com/ https://www.swanwicksleep.com/ I choose the safety glass instead of the swanwick glass because I have more confidence that a safety glass in conforming with the provided specification. Since I intend to use it home, I don't care about how it looks. It you want to customize your own glass, this company sells lens blank of filter that block a somewhat similar wavelength to the other products: https://laserprotection.com/product/laser-pointer-protective-lens-nite/ https://laserprotection.com/product/laser-pointer-protective... Zeiss also sells special lens for colorblind that blocks similar spectrum. But it is very hard to find information on how to get them online.
LeeOldAss 5y ago
vedtopkar 5y ago
They speculate that the harmful component of e-readers is the blue-shifted illumination. I’d be curious if newer e-readers with temperature controllable backlights set to “warm” mitigates some of this sleep harm
- zachruss92 5y ago
  Also the kindles use significantly less light that aren’t emitted directly into your eyes (rather up/down on the screen). That’s what I thought this study was at first. I have a non illuminated kindle for years and I’m wondering the same thing for when I inevitably have to replace it. A built in warm & dim light is convenient especially if it doesn’t adversely affect things. If not back to candles for me!
shrikant 5y ago
[2014] Also, it was shockingly hard to find [for me], but the "light emitting ereader" referred to in the title was an Apple iPad. It's not specified what kind of iPad they used, and the study focussed solely on reading from the iPad vs reading from a printed book. The authors do note (in Table S1, in the Supporting Information) that they don't consider a Kindle e-reader to be light-emitting. (I'm not throwing shade (heh) at the study, just adding some pertinent information that I thought would be useful to know.)
- mekkkkkk 5y ago
  Shade throwing would be justified in my opinion. "E-reader" isn't normally used to describe tablets. The light profile of a dynamic LED screen is probably very different from the ambient steady backlight on a Kindle.
  - JKCalhoun 5y ago
    Kindles have a backlight? Then I expect it to be LED as well. I'm not sure then you can be so dismissive of a back-lit Kindle and its effect on evening reading.
    - nicoburns 5y ago
      They have a frontlight rather than a backlight. And there's quite a bit of evidence that colour temperature and brightness both have a big effect. But I broadly agree that it will still have an effect. I use my kindle without the backlight and with a warm coloured lamp.
    - evancox100 5y ago
      Technically it’s a front-light, shining on the front of the screen from the side. But the nature of the eInk is such that you don’t have to use the built in light, you could just turn in your normal lamp.
    - mekkkkkk 5y ago
      I'm not dismissing it having an effect. But isn't it probable that the light profile would be somewhat different for an actual monitor and a back/sidelit eInk dislay? If so, the effect may differ as well.
dr1s 5y ago
Classifying an iPad as an eReader is a bit misleading IMHO. I would have never made the connection if it wasn't mentioned in the article. The intensity of light needed on an iPad to read comfortably is much higher then a backlit eInk reader e.g. a Kindle Paperwhite. Personally it doesn't affect me very much on such devices, but it would be interesting to see if there is a noticeable difference.
RistrettoMike 5y ago
Came here to add another voice to the discourse that an iPad is most definitely not a "light-emitting eReader" in popular vernacular. That term calls to mind recent e-ink devices with frontlights, which are often used in place of LCD-devices to allow for some time away from harsher backlit screens before bed. Burying that lede several sections deep feels almost purposely misleading, either that or just incompetent in my opinion.
steelframe 5y ago
From TFA: > The LE-eBook was set to the maximum brightness setting. Others on this thread have pointed out that it's an iPad. For years now, this has seemed like common sense to me. Of course you don't want to blast a tablet or laptop screen at 100% brightness when you're trying to get your brain to fall asleep. I use a Kobo e-reader with its brightness set to 1%. I can't imagine that exposes my eyes to light amplitudes that would exceed that of a lamp. In a dark room I don't have any problem reading the words, and I don't think I've had any sleep problems.
flatiron 5y ago
i don't use an ipad, i use a kindle pw2, but i feel like i can get to sleep quicker when reading than if i just plop down into bed and close my eyes.
aaron695 5y ago
monocularvision 5y ago
My anecdotal two-cents: I will stay up nearly indefinitely in bed if I read my phone or iPad. Read the same material on my Kindle Paperwhite and it can be difficult to stay awake more than a few minutes. I don’t know if it has anything to do with the difference in screen types, as my Kindle does have a backlight but it is so night and day for me, I am predisposed to believe anything that states there is a mechanism for my experience.
- IRP 5y ago
  Leds in a phone or tablet screen are directing the light to your eyes, where with a backlit screen, that light is diffused over the area of the screen. So the intensity of direct light from "LE-eReaders" is probably way higher than that of a backlit screen. Also, it might have to see with the level of blue light that is emitted by those devices. Light in backlit screens is somewhat filtered and might not contain as much blue.
  - Karawebnetwork 5y ago
    Elsewhere I would agree with you but this study was using: "The randomized, crossover protocol design consisted of two conditions: (i) reading an LE-eBook (iPad; Apple Inc., Cupertino, CA) in otherwise very dim room light for ∼4 h before bedtime for five consecutive evenings, and (ii) reading printed books in the same very dim room light for ∼4 h before bedtime for five consecutive evenings" In other words, they compared using a tablet to reading a book. Unsurprisingly, they found that using the tablet negatively affects sleep.
    - manicdee 5y ago
      During LE-eBook reading sessions, the light-emitting device was set to maximum brightness and placed in a stand that held it at a fixed angle. This stand was placed on a table directly in front of the individual at a 30- to 45-cm distance from their eyes. Participants were allowed to turn pages on the LE-eBook, but were asked not to hold it while reading or make any adjustments to the settings. During the printed book reading sessions, participants were allowed to hold the book at any desired distance from their eyes. —— Note that maximum brightness on an iPad is intended for reading in direct sunlight.
bebna 5y ago
Because this article is about ipad vs book, here is my personal experience with eInk readers (no Light Sony PRS-350, light layer Kobo Aura HD) and personal setup of red on black on amoled on minimal lightness Samsung Note 10: Personally I define something to not affect my sleep, when I got trouble staying awake after one or two chapters on a workday. PRS-350 (no light eink): Like a real book, it mostly depends on the light setup of the room. With a warm, indirect and just enough to not have trouble reading dim light, I easily get sleepy and in trouble to stay awake long enough to poweroff device and lamp. I did fall asleep with device in hand often enough, even on a plane once. Aura HD (light layer eink, one of the first gens): Had to stop myself reading often after looking at the clock or how many chapters I read. Just one more chapter, was a real problem with it. But I didn't had any trouble falling asleep after putting it away. Note10 kobo reader (amoled, red text on black, "background light off mode"): Need more time than PRS-350 or real book, but I definitely got trouble keeping my eyes open after a while. Sometimes I switch it off and already fall asleep before I get the chance to put the phone out of my hand. Note10 anime reader app/websites/etc: Even without videos or other animated/interactive media, I stay awake indefinitely. If I fall into that trap, it is common for me to stay awake to at least 2am, sometimes up to 5am.
oidar 5y ago
iPad on full brightness is not the same thing as an ereader. This study has some serious problems. I'm surprised there hasn't been a recent study with the current generation of ereaders (Kindle Oasis in particular) that measures melatonin level. Ideally, I'd like to see light levels calibrated to the same level between an eink device vs LED tablet vs an actual book vs a no bedtime reading condition.
- ben7799 5y ago
  In my experience the iPad & iPhone cannot approach the dim levels side-lit eInk readers can. The minimum brightness on iPad/iPhone is about 50% of max on my Kindle Oasis, so it might be hard to do a realistic study comparing the two, one or both of the devices would end up far out of the normal range users would select in order to match brightness. If I'm reading in a darkened room on my kindle I have the brightness on the kindle set lower than it's possible to do so on an iPhone or iPad. I think this is common, which shows how crazy it is the study had an iPad on maximum brightness and had the user read for hours in that configuration. I'd have red eyes and a splitting headache by the end of that which would of course have negatively effected my sleep.
ben7799 5y ago
iPad on maximum brightness is what they were using. They sure buried it! That would be close to painful and certainly very unpleasant in a dim room at night.. WTH were the study authors thinking? The iPad won't even do that without the user manually setting it up to do that, and almost no one is going to find it comfortable. It seems more like they were trying to set the conditions to get the result they desired. They could have shined an LED flashlight into the user's eyes and gotten the same result.
- mpalczewski 5y ago
  > WTH were the study authors thinking? They were thinking that they wanted a publishable result. Unfortunately, little to no difference on sleep between dim e-reader at night vs book and dim light wouldn't get published even though would be really useful to know.
  - Beltalowda 5y ago
    It would seem to me that "there is no difference with appropriate light intensity settings" would be a much more publishable result? That max. brightness affects sleep is an unsurprising "common sense" result (although still worth doing research over just to verify), but I – and I think many people – genuinely don't know if there's an effect with low light settings (and/or colour temperature settings), and if there's an effect, how large that effect might be. In short: that seems a much more interesting study.
sandos 5y ago
Pro-tip: use the kindle paperwhite on 3-6 brithgness and fall asleep easily! It works wonders for me, honestly, I find I fall asleep easier with reading on a not-bright e-ink reader. I also have a kobo reader which is more yellow in its hue, but also a tad brighter. That one also works well for me, I usually put the reader down in 10 minutes to sleep.

33 points by ivanvas 5y ago

I wonder if the type of illumination used for traditional book reading is relevant. I.e. would a bedside lamp with cold light provoke the same effects?

zachruss92 5y ago
From my understanding from what experts say any light will affect your sleep to some extent. The big issue with backlit screens are that the blue lights are projected directly into your eyes which compounds the effects as more photons hit your eyes.
- mekkkkkk 5y ago
  Is that true though? I was under the impression that two surfaces with the same perceived brightness would bombard your eyeballs with the same amount of photons. Regardless of whether or not the surface is emitting or reflecting light. On the other hand, maybe there is some filtering taking place when light is bounced off materials. I.e. blue wavelengths being absorbed by the paper.
- bXVsbGVy 5y ago
  This is both correct and wrong. Some lights affected more than others. A paper[1] funded by NIH published this year showed that ~12 log photons cm⁻² s⁻¹ on λ=460nm is enough to suppress melantonin production. I've discussed more on sibling thread. [1] https://journals.sagepub.com/doi/pdf/10.1177/0748730415585413 https://journals.sagepub.com/doi/pdf/10.1177/074873041558541...
nicoburns 5y ago
> would a bedside lamp with cold light provoke the same effects Almost certainly from my own anecdotal experience. There's a reason why bedroom lights tend to be warm (even though they're often now leds)
bXVsbGVy 5y ago
I spent the past weekend reading papers of blue light effects on melatonin suppression to decided if blue light blocking glass was supperted by science, and to know and to know the parameters I should consider. As today, the academic consensus is that Melatonin suppression, on the lower part of the spectrum, is regulated by melanopsin produced by the Intrinsically photosensitive retinal ganglion cells (ipRGCs) -- not blue rods. The photosensitivity of ipRGCs has λ_peek = ~460 (nm). They've done experiments with rats without cones and rods (but with ipRCS), and they displayed circadian cycles. Melatonin is also suppressed by lights on higher part of the spectrum, but haven't papers on it. I've decided in getting this safety glass: https://www.thorlabs.com/thorproduct.cfm?partnumber=LG3A https://www.thorlabs.com/thorproduct.cfm?partnumber=LG3A The dark amber glass from swanwick have similar optical density curve: https://www.swanwicksleep.com/ https://www.swanwicksleep.com/ I choose the safety glass instead of the swanwick glass because I have more confidence that a safety glass in conforming with the provided specification. Since I intend to use it home, I don't care about how it looks. It you want to customize your own glass, this company sells lens blank of filter that block a somewhat similar wavelength to the other products: https://laserprotection.com/product/laser-pointer-protective-lens-nite/ https://laserprotection.com/product/laser-pointer-protective... Zeiss also sells special lens for colorblind that blocks similar spectrum. But it is very hard to find information on how to get them online.

LeeOldAss 5y ago

vedtopkar 5y ago

They speculate that the harmful component of e-readers is the blue-shifted illumination. I’d be curious if newer e-readers with temperature controllable backlights set to “warm” mitigates some of this sleep harm

zachruss92 5y ago
Also the kindles use significantly less light that aren’t emitted directly into your eyes (rather up/down on the screen). That’s what I thought this study was at first. I have a non illuminated kindle for years and I’m wondering the same thing for when I inevitably have to replace it. A built in warm & dim light is convenient especially if it doesn’t adversely affect things. If not back to candles for me!

shrikant 5y ago

[2014] Also, it was shockingly hard to find [for me], but the "light emitting ereader" referred to in the title was an Apple iPad. It's not specified what kind of iPad they used, and the study focussed solely on reading from the iPad vs reading from a printed book. The authors do note (in Table S1, in the Supporting Information) that they don't consider a Kindle e-reader to be light-emitting. (I'm not throwing shade (heh) at the study, just adding some pertinent information that I thought would be useful to know.)

mekkkkkk 5y ago
Shade throwing would be justified in my opinion. "E-reader" isn't normally used to describe tablets. The light profile of a dynamic LED screen is probably very different from the ambient steady backlight on a Kindle.
- JKCalhoun 5y ago
  Kindles have a backlight? Then I expect it to be LED as well. I'm not sure then you can be so dismissive of a back-lit Kindle and its effect on evening reading.
  - nicoburns 5y ago
    They have a frontlight rather than a backlight. And there's quite a bit of evidence that colour temperature and brightness both have a big effect. But I broadly agree that it will still have an effect. I use my kindle without the backlight and with a warm coloured lamp.
  - evancox100 5y ago
    Technically it’s a front-light, shining on the front of the screen from the side. But the nature of the eInk is such that you don’t have to use the built in light, you could just turn in your normal lamp.
  - mekkkkkk 5y ago
    I'm not dismissing it having an effect. But isn't it probable that the light profile would be somewhat different for an actual monitor and a back/sidelit eInk dislay? If so, the effect may differ as well.

dr1s 5y ago

Classifying an iPad as an eReader is a bit misleading IMHO. I would have never made the connection if it wasn't mentioned in the article. The intensity of light needed on an iPad to read comfortably is much higher then a backlit eInk reader e.g. a Kindle Paperwhite. Personally it doesn't affect me very much on such devices, but it would be interesting to see if there is a noticeable difference.

RistrettoMike 5y ago

Came here to add another voice to the discourse that an iPad is most definitely not a "light-emitting eReader" in popular vernacular. That term calls to mind recent e-ink devices with frontlights, which are often used in place of LCD-devices to allow for some time away from harsher backlit screens before bed. Burying that lede several sections deep feels almost purposely misleading, either that or just incompetent in my opinion.

steelframe 5y ago

From TFA: > The LE-eBook was set to the maximum brightness setting. Others on this thread have pointed out that it's an iPad. For years now, this has seemed like common sense to me. Of course you don't want to blast a tablet or laptop screen at 100% brightness when you're trying to get your brain to fall asleep. I use a Kobo e-reader with its brightness set to 1%. I can't imagine that exposes my eyes to light amplitudes that would exceed that of a lamp. In a dark room I don't have any problem reading the words, and I don't think I've had any sleep problems.

flatiron 5y ago

i don't use an ipad, i use a kindle pw2, but i feel like i can get to sleep quicker when reading than if i just plop down into bed and close my eyes.

aaron695 5y ago

monocularvision 5y ago

My anecdotal two-cents: I will stay up nearly indefinitely in bed if I read my phone or iPad. Read the same material on my Kindle Paperwhite and it can be difficult to stay awake more than a few minutes. I don’t know if it has anything to do with the difference in screen types, as my Kindle does have a backlight but it is so night and day for me, I am predisposed to believe anything that states there is a mechanism for my experience.

IRP 5y ago
Leds in a phone or tablet screen are directing the light to your eyes, where with a backlit screen, that light is diffused over the area of the screen. So the intensity of direct light from "LE-eReaders" is probably way higher than that of a backlit screen. Also, it might have to see with the level of blue light that is emitted by those devices. Light in backlit screens is somewhat filtered and might not contain as much blue.
- Karawebnetwork 5y ago
  Elsewhere I would agree with you but this study was using: "The randomized, crossover protocol design consisted of two conditions: (i) reading an LE-eBook (iPad; Apple Inc., Cupertino, CA) in otherwise very dim room light for ∼4 h before bedtime for five consecutive evenings, and (ii) reading printed books in the same very dim room light for ∼4 h before bedtime for five consecutive evenings" In other words, they compared using a tablet to reading a book. Unsurprisingly, they found that using the tablet negatively affects sleep.
  - manicdee 5y ago
    During LE-eBook reading sessions, the light-emitting device was set to maximum brightness and placed in a stand that held it at a fixed angle. This stand was placed on a table directly in front of the individual at a 30- to 45-cm distance from their eyes. Participants were allowed to turn pages on the LE-eBook, but were asked not to hold it while reading or make any adjustments to the settings. During the printed book reading sessions, participants were allowed to hold the book at any desired distance from their eyes. —— Note that maximum brightness on an iPad is intended for reading in direct sunlight.

bebna 5y ago

Because this article is about ipad vs book, here is my personal experience with eInk readers (no Light Sony PRS-350, light layer Kobo Aura HD) and personal setup of red on black on amoled on minimal lightness Samsung Note 10: Personally I define something to not affect my sleep, when I got trouble staying awake after one or two chapters on a workday. PRS-350 (no light eink): Like a real book, it mostly depends on the light setup of the room. With a warm, indirect and just enough to not have trouble reading dim light, I easily get sleepy and in trouble to stay awake long enough to poweroff device and lamp. I did fall asleep with device in hand often enough, even on a plane once. Aura HD (light layer eink, one of the first gens): Had to stop myself reading often after looking at the clock or how many chapters I read. Just one more chapter, was a real problem with it. But I didn't had any trouble falling asleep after putting it away. Note10 kobo reader (amoled, red text on black, "background light off mode"): Need more time than PRS-350 or real book, but I definitely got trouble keeping my eyes open after a while. Sometimes I switch it off and already fall asleep before I get the chance to put the phone out of my hand. Note10 anime reader app/websites/etc: Even without videos or other animated/interactive media, I stay awake indefinitely. If I fall into that trap, it is common for me to stay awake to at least 2am, sometimes up to 5am.

oidar 5y ago

iPad on full brightness is not the same thing as an ereader. This study has some serious problems. I'm surprised there hasn't been a recent study with the current generation of ereaders (Kindle Oasis in particular) that measures melatonin level. Ideally, I'd like to see light levels calibrated to the same level between an eink device vs LED tablet vs an actual book vs a no bedtime reading condition.

ben7799 5y ago
In my experience the iPad & iPhone cannot approach the dim levels side-lit eInk readers can. The minimum brightness on iPad/iPhone is about 50% of max on my Kindle Oasis, so it might be hard to do a realistic study comparing the two, one or both of the devices would end up far out of the normal range users would select in order to match brightness. If I'm reading in a darkened room on my kindle I have the brightness on the kindle set lower than it's possible to do so on an iPhone or iPad. I think this is common, which shows how crazy it is the study had an iPad on maximum brightness and had the user read for hours in that configuration. I'd have red eyes and a splitting headache by the end of that which would of course have negatively effected my sleep.

ben7799 5y ago

iPad on maximum brightness is what they were using. They sure buried it! That would be close to painful and certainly very unpleasant in a dim room at night.. WTH were the study authors thinking? The iPad won't even do that without the user manually setting it up to do that, and almost no one is going to find it comfortable. It seems more like they were trying to set the conditions to get the result they desired. They could have shined an LED flashlight into the user's eyes and gotten the same result.

mpalczewski 5y ago
> WTH were the study authors thinking? They were thinking that they wanted a publishable result. Unfortunately, little to no difference on sleep between dim e-reader at night vs book and dim light wouldn't get published even though would be really useful to know.
- Beltalowda 5y ago
  It would seem to me that "there is no difference with appropriate light intensity settings" would be a much more publishable result? That max. brightness affects sleep is an unsurprising "common sense" result (although still worth doing research over just to verify), but I – and I think many people – genuinely don't know if there's an effect with low light settings (and/or colour temperature settings), and if there's an effect, how large that effect might be. In short: that seems a much more interesting study.

sandos 5y ago

Pro-tip: use the kindle paperwhite on 3-6 brithgness and fall asleep easily! It works wonders for me, honestly, I find I fall asleep easier with reading on a not-bright e-ink reader. I also have a kobo reader which is more yellow in its hue, but also a tad brighter. That one also works well for me, I usually put the reader down in 10 minutes to sleep.