Video: "How Electric Light Changed The Night"


In a 2014 Penn State study, people read either e-books or paper books before sleep. The subjects who had read from tablets took longer to fall asleep, slept less restfully and performed worse on cognitive tests the next day compared to those who had read paper books.

Ebooks (as in epaper) or tablets? This is a pretty critical omission, since they are pretty different beasts. I’m guessing they meant tablets, but a little bit of clarity goes a long way. I pretty much closed the video at this point, since anything else they claim would also be vague and dubious, and thus of no real use to me.

Also, can we please actually LINK to studies we reference in our stories?

Second link in a google search. One of the researchers is named. You can write to her if you want.

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Much better headline, but still overly vague. Who refers to their tablet as an “e-reader”? I refer to my e-reader as an “e-reader”, and I refer to my tablet as a “tablet”, they are different beasts entirely, even on the, very rare, occasions I read ebooks on my tablet.

That said, I’m sure the actual study is valid. But the video linked here was flat out wrong, thanks to their sloppy use of language.

Hi, Jehovazilla. Thanks for pointing out the vague language in my article. I’ve made a correction that will hopefully clear this up for future readers.

Arwen Curry
KQED Science


It doesn’t help that at least in the last one I read about the subjects had to use the tablet for 4 hours and at full brightness which I know I sure as hell never do. Anyone would have sleep issues staring at a bright white screen for 4 hours before going to bed. I imagine most of the others are similar.

I always have the brightness cranked down and have it set to a night mode with white text on a black background and it would be nice to see a study of it with optimized brightness and color schemes used.

Also a bright light in your room is just the same if it is emitting the same wavelengths that keep up awake cause light going into your eyes is light going into your eyes whether it comes from the tv screen, pc screen, table screen or bedside lamp. Though granted a bedside lamp is not always going to be uber bright and probably will be diffused a bit but I don’t think our bodies care about that.

You might also try using a program called Flux. It changes the color temperature of your screen at night to make the light much less jarring to your eyes. I consider it a necessity on any computer I’m using at night. Its available for Windows, Mac and iOS, though the iOS version unfortunately requires that you jailbreak your device since the App Store can be stupid sometimes.

Yeah I know about that one and have been quite lazy about getting it and really should at least for the nook. So far I am good with just screen at minimum brightness and night mode. I find I start nodding off faster than when I turn on the light and read paper books especially on the odd time oh, 2am and I am AWAKE and go out the living room and sprawl out on the couch. With a light on I have burned through many more pages of reading paper books than just the tablet for reading in an otherwise dark room.

Thank you!

I can’t state how impressed I am at the moment, most of online journalism could learn a lesson from you!

@TobinL: I ran into sleep issue when using my tablet for reading comics before bed (at auto-brightness, in a dim but lit room). Horrible sleep issues, its hard to describe, but its like I had a full-bright after image of a comic page in head for 4-5 hours after turning off the light, every time I closed my eyes. This doesn’t happen with my ancient Nook with eink. Obviously anecdotal, but it does lead me to believe the study.

Comics/graphics tend to want max brightness and I don’t do a lot of reading of comics in general anyway. I always make sure I have cranked it down and switch to dark background and I haven’t noticed any more or less trouble getting to sleep than reading paper books.

[quote=“TobinL, post:6, topic:50378”]Though granted a bedside lamp is not always going to be uber bright and probably will be diffused a bit but I don’t think our bodies care about that.
Light going into your eyes is light going into your eyes, but the intensity of it makes a difference. Your body definitely cares about the diffusion difference between seeing a green laser and having one shone directly into your eyes.

Well lasers, duh. Do not shine in remaining eye.

I vaguely recall hearing an explanation that there was less of an issue when reading a paper (or e-ink) book because the light there is reflected off the page into your eyes, as opposed to shining directly into your eyes from the light source. But I may have completely fabricated that in my mind, as well. I wonder if newer e-readers with built in lights (kindle paperwhite, etc) have the same issues.

I have Flux on my iPad, and love it. Though it takes a bit of getting used to the colour temp changes that it gives.

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