
E-Readers Foil Good Night’s Sleep - walterbell
https://hms.harvard.edu/news/e-readers-foil-good-nights-sleep
======
dade_
"Backlit devices" would be much more accurate, but I doubt this information is
news to anyone here. I have a Kobo, but use an external LED clip light. To
solve the problem, I popped the external light open and replaced the "white"
LED (which are actually blue) with and RGB LED and only connected the red and
green LED. It is plenty bright for reading, but I am surprised that I've never
found an actual product that does this.

------
manicdee
Note: the people reading paper books were allowed to adjust their position and
the book's position while reading.

The people reading the "LE-eBook" (i.e.: iPad) were forced to do their reading
with the iPad locked into position and the brightness turned to maximum, for
four hours.

I find it hard to accept the study's findings that it was "use of these
devices [that] prolongs the time it takes to fall asleep," rather than, say,
having a bright light shone in your eyes and not being allowed to shift
position while reading for four hours.

The iPad's brightness can be turned down much lower than an equivalent paper
book illuminated by a reading lamp. Even better, the iPad's illumination will
not disturb your sleeping partner as much as a bed lamp (the latter
illuminates the whole room).

I'd like to see this study repeated with paper books vs paper books, with
books fixed in place on the table, and one group's books illuminated with a
spotlight providing equivalent illumination to the reader's face as the
maximum-brightness iPad.

Then run a parallel study with all readers using iPads, with some having the
brightness fixed to maximum and others free to adjust brightness to their own
comfort.

------
koralatov
The title of the article is misleading, as the participants were reading on a
tablet, not an e-reader. ( _" During the two-week inpatient study, twelve
participants read digital books on an iPad for four hours before bedtime each
night for five consecutive nights."_)

Having used an iPad, a Kindle, and a Kobo, I know from experience that there's
a _huge_ difference in the quality and intensity of light emitted by the
devices. At its lowest setting, an iPad emits much, much more light than an
e-reader at its lowest setting, and the e-readers I've used have to get above
25% or so before they begin to match the light intensity of the iPad at its
lowest setting. The displays also differ in the way they're lit: tablet LCDs
are backlit, and e-readers are generally front-lit, with the light being
pointed at the screen and bouncing back off it.

I wouldn't be surprised if the blue/white light used on e-readers also affects
sleep, but I think a study needs to be carried out using those devices before
it can be concluded that they do.

~~~
walterbell
The Marvin e-reader app on iOS can control color temperature, to reduce blue
content,
[http://www.appstafarian.com/marvin.html](http://www.appstafarian.com/marvin.html)

It's unfortunate that iOS does not have platform-wide support for adjusting
color temperature.

------
rahimnathwani
The headline doesn't reflect the content: "Although iPads were used in this
study, researchers also measured other devices that emit blue light, including
eReaders, laptops, cell phones and LED monitors."

So, they did a user study using iPads, and only measured the other devices.
They then claim the results apply to those other devices.

TFA didn't have a link to the paper (as far as I could tell), but it's here:
[http://www.pnas.org/content/112/4/1232.full?sid=a0e8cb09-0a5...](http://www.pnas.org/content/112/4/1232.full?sid=a0e8cb09-0a58-4213-b68f-e400a8efe21d)

"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 (Fig. 1)."

This seems like a strange test. When I read a physical book in bed, I need
more light (e.g. from a lamp) than when I'm reading on a Kindle or an iPad
(which I often read with the lights off, which also means I can turn the
backlight to a low setting).

~~~
manicdee
Even stranger is that the iPad was fixed in position on the table, with
brightness set to maximum.

The maximum brightness on an iPad means you can read the screen in broad
daylight. I can not see how this level of brightness lends itself to bedtime
reading in a dimly lit room.

------
Spittie
Interesting, I've been wondering about this myself lately, as I've started to
read on an e-book reader ~30 minutes before going to sleep as a part of my
routine. Too bad they only used iPads for this study.

I wonder if it's better for my sleep to read a "normal" book with the lights
on, or if it's better to read with an ereader with the minimum amount of
brightness on. I think I receive less blue light with the second case, but
maybe it's more direct into my eyes? I also wonder if there is a difference
between a "normal, backlit screen" and an "e-ink frontlit screen" at the same
brightness.

And it's a bummer that no-one sells an ereader with a "flux" mode.

~~~
walterbell
You can buy ambient lighting that has low blue content, e.g. the "Evening PM"
version of the GE Align,
[http://www.amazon.com/gp/product/B00PLR3M0M](http://www.amazon.com/gp/product/B00PLR3M0M)

------
lamby
As all the other commenters have mentioned (separately for some reason..),
this is a misleading title.. However, I'd still read some fiction on a backlit
e-reader than go through my emails and TODO list on my laptop from the
relaxation point of view.

------
coolandsmartrr
The title could be misleading. It's _light-emitting_ e-readers that affect
sleep cycles, especially iPads which they used in the study.

That means my sleep shouldn't be distracted significantly just because I read
on my non-backlit Kindle.

~~~
manicdee
It's even more misleading than that. The study really only demonstrated that
having a spotlight shone in your face for four hours before going to bed will
interfere with your sleep.

------
wlesieutre
Crappy choice of terminology for this article. They're talking about reading
in iPads (or other backlit LCDs, presumably).

Was hoping for some insight on frontlit eInk readers like the Nook Glowlight
or Kjndle Paperwhite.

------
nielsk
E-Readers is wrong. The study used as a "light-emitting" book an iPad (p.
1235). So it is tablets and smartphones. It is not even clear to me if a
Kindle Paperwhite would fall into the category.

~~~
manicdee
The Kindle Paperwhite can not be turned up as bright as the iPad can, which
would mean that the results of this study do not apply. The results of the
study are basically that having bright light shone in your eyes interferes
with your sleep (nothing to do with iPad vs book).

