Kindle better for reading during the day, iPad at night may lead to loss of sleep

Let’s start with an interesting 2 person experiment that Jason Perlow at ZDNet carried out. It involved two people reading books and experiencing reading on both iPad and Kindle in various lighting conditions. They then note down their thoughts on whether the eInk screen of the Kindle really is better for reading than the iPad’s LCD.

ZDNet’s 2 person reading experiment finds Kindle and eInk better for reading during the day and in sunlight

Here’s what Jason Perlow found when comparing Kindle and iPad for reading

  1. Kindle and Sony Reader were better for indoor daylight reading than iPad.
  2. Kindle for iPad is better than iBooks.
  3. The iPad is a total no-go in sunlight. eReaders work great in sunlight.

The post has exact details on the amount of time for which the two readers could read on the various devices before their eyes got tired.

For people who feel that reading on LCD does not tire the eyes these figures should be interesting –

Living Room: With the iPad, I was only able to go for about 45 minutes (before experiencing significant eye strain).

Kitchen (more light): was able to read for approximately 15-20 minutes before experiencing significant eyestrain and discomfort. Sandi again fared a little better, with about 30 minutes of tolerance.

The experimenters find the iPad is unreadable outside –

Outdoors, it was a total fail for the iPad. The screen immediately turned into a mirror … was completely unreadable

Contrast that with what one of the first 5 ‘official‘ iPad reviewers, Andy Ihnatko, wrote in his iPad Review

My first full day out-and-about with the iPad underscored a problem with the display: the glossy screen can create a lot of glare.

… Glare aside, the screen does work fine in bright sunlight if you’ve got the screen brightness set to 100% …

The Press are writing that the iPad is readable in sunlight when the reality is that its screen turns into a mirror.

How can we trust the Press to be right about their claims that LCD is just as good for reading as eInk?

This ZDNet experiment is important in that –

  1. It had two people actually read a book (as opposed to look at the screen for 5 minutes and say it’s fine).
  2. It had both people experience eye-strain.
  3. They experienced eye-strain sooner on the LCD screen of the iPad than on the eInk screen of the Kindle.

The iPad apologists will be happy to know that they found different results for night.

iPad shines at night

For night reading they tried reading from 10 pm to midnight under complete darkness and also with the help of a bedside lamp.

Here’s what Jason Perlow found for night reading with eReaders –

  1. Eye strain after 40 minutes of reading with the bedside lamp for both eReader and iPad. 
  2. With a clip-on LED light and an eReader he could read for hours. However, the light would be distracting to his wife.
  3. Sandi found reading on Kindle with a reading light was comfortable. However, her spouse would get disturbed.

Here’s what he found for night reading with the iPad –

  1. Kindle for iPad works really well with White text on a Black background.
  2. This also reduces the amount of light coming out and thus is far less likely to disturb his wife.
  3. His friend found black text on white with 10% to 15% brightness worked well for her.

He ends with this –

both Sandi and I were very surprised how well the iPad performs in dimly lit rooms and in complete darkness.

If it weren’t for the considerable heft of the iPad, she would strongly consider using one to replace her Kindle for reading in bed at night, citing less chance for disruption of her spouse and less eyestrain than using a Mighty Brite or similar LED clip lamp with the Vizplex display on the Kindle

It’s remarkable that even after finding the iPad to be better for reading at night the experimenter is sticking with her Kindle. It’s because the iPad is too heavy and awkward – 1.5 pounds means heavier than a big hardcover.

The ‘iPad is better for reading at night’ conclusion seems pretty cut and dry – until we factor in another article that fortuitously came out this morning.

iPad tells the brain to stay awake and messes with your sleep cycle

The LA Times has an article where sleep experts (credentials below) say using iPad before bed can affect sleeping habits while eReaders like the Kindle are safe.

Here’s why the iPad’s backlight is a problem –

… direct exposure to such abnormal light sources (such as the iPad’s backlight) inhibits the body’s secretion of melatonin, say several sleep experts.

In this regard the iPad is actually worse than TV –

Light-emitting devices, including cellphones and yep, the iPad, tell the brain to stay alert.

Because users hold those devices so close to their face, staring directly into the light, the effect is amplified compared with, say, a TV across the room or a bedside lamp, said Frisca Yan-Go, director of the UCLA Sleep Disorders Center in Santa Monica.

Then we have another expert chime in –

“The take-home lesson is that insomnia and electronics gadgets emitting light should not [be] mixed before bedtime,” UCLA Neurology Clinic Director Alon Avidan, also an associate professor at the university, wrote in an e-mail. However, “Kindle is better for your sleep,”

That’s certainly interesting.

All signs point to eInk powered dedicated reading devices

Let’s summarize what the experiments are telling us –

  1. eInk readers like the Kindle are better for reading with natural light.
  2. They also cause less eyestrain (or to put it another way you can read longer without straining your eyes).
  3. iPad is unreadable in sunlight.
  4. iPad is better for reading in the dark as there’s no need for a reading light that would distract other people.
  5. iPad caused less eye strain (for one reader) than reading an eInk screen with a reading light.

It seems like a simple conclusion – eReaders for daytime and sunlight and iPad and LCD screens for night.

Except the sleep disorder experts blow away the case for using iPad and LCD screen reading devices in the dark. According to them (and you have to admit its pretty sound logic) –

  1. Reading on the iPad means our brains get the signal to stay alert.
  2. The effect of the iPad is worse than a TV or a reading lamp.
  3. The iPad messes with our sleep cycle.

If the experts are right then it means that the iPad isn’t just great for reading in the dark – it’s so great that you’ll begin to lose sleep.

11 thoughts on “Kindle better for reading during the day, iPad at night may lead to loss of sleep”

  1. I have found backlit screens to affect my sleep patterns. I have to stop looking at my ipod and computer by about 8pm if I want to sleep by 11:30pm or so, and have a deep night’s sleep. Otherwise, it takes way longer for me to go to sleep, and I wake frequently during the night and sleep lighter. I’ve always advised friends or relatives with insomnia to shut off their pc’s in the evening and it always helps (if not cures) their problem. I also surf from my wii connected to my tv, and that even messes with my sleep due to the big tv screen being mostly white. So I’m a real life example of the “sleep loss due to gadgets” claim. The experts are right on! 🙂

    1. Gina, it’s the same with me. Reading on the iphone at night in bed messes up my sleep as does blogging late at night.
      It never really struck me that it makes sense to give the eyes and brain a few hours away from a bright screen to help get them ready for sleep – it seems so obvious.

  2. It seems as if none of the information given has been proven through controlled scientific studies. Supporters of both the Kindle and iPad can say whatever they want to make the positives cases for the favored devices. The opposite holds true, too.

    Some of the statements made cause me to wonder how aged the eyes are that are experiencing all the eyestrain.

    1. Patricia, do you regularly read novels on your notebook computer or PC? Do you think the Kindle PC application is just as good as the Kindle device? If not, why not, other than portability?

      If you do happily read novels on your computer, than it seems eye-strain isn’t an issue for you. The rest of us prefer to use computers for reading websites, blog entries, and email – that is to say, we prefer to use it for short form reading.

    2. It’s a good point – my original heading for the first section was ‘Unscientific survey says …’ . It’s just a 2 person survey – However, it’s important because this is people actually reading a book and then comparing.
      It might seem ridiculous to be happy that people are now actually reading a book before making claims on what is a better eReader – However, it’s a big step forward.

      Would tend to think the Sleep Disorder experts are basing their words on a lot of experience and knowledge – However, it would be nice to see some proper peer-reviewed papers to back it up.

  3. I’m sorry. But neither of these articles are studies, or experiments. They are opinion articles. The ZNet study is from a tech writer, with zero scientific anything. Once again, your biased ridiculous writing is utter nonsense.

    1. thanks for your comment. You’re right.

      We now have unscientific, ridiculous writing in favor of both the iPad and the Kindle. Equity is a beautiful thing.

  4. Has anyone tried using a red light to read their kindle in bed?

    Might not be as annoying for your spouse, and preserves night vision.

  5. People who complain that the iPad display causes eyestrain need to learn to properly adjust the brightness. I can read for hours on my iPad with no problem. eInk is simply not better than a properly adjusted IPS LCD except in full on sunlight. The iPad display is awesome.

    That said, I do agree that the iPad may not be the best thing for sleep patterns. I’m not sure how much of it is due to backlighting and how much to simple diversion, but I’ve had some late nights with my iPad.

    1. Agree with you on the late nights. Not on the iPad’s screen though.

      I’m an LCD-incompatible and reading on the iPad gives me a headache. I’ve had a 24″ IPS LCD monitor for my computer since 2009 and trust me – no matter of ‘proper adjustment’ or changing brightness can help people who are LCD-incompatible.

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