Study: E-ink is NOT Better for Your Eyes Than LCDs

If you've been reading ebooks for any length of time then you've probably heard about how E-ink screens are nicer on the eyes than LCD screens. It's simply common sense that not having a light shine in your face must be better for you, and that is why E-ink Corp wants everyone to switch their reading over to devices with its screens.

But like some common sense assumptions, this one doesn't stand up to scientific scrutiny. A paper published in Ophthalmic and Physiological Optics last month reveals a fascinating study which suggests that it's the resolution more than the screen tech which has a harmful effect.

The paper discusses the results of a laboratory study. A group of 10 test participants were asked to read on either LCD or E-ink for several hours, and they were then tested through several objective methods (letter search task, reading speed, and pupillary light reflex) as well as subjectively queried about eye and general fatigue. The devices used in the test were the original iPad and the Sony PRS-600, and that is a detail which might influence the subjective questions (the iPad is bigger and heavier).

This question of the damaging effect of LCD screens is a chronic one, given the rise in tablets and smartphones as reading devices, and it is long past time that it was moved beyond subjective arguments to a discussion which includes real data.

And now we have it.  The results of the study didn't show a significant difference in reading on the two types of screens, and in fact that the effect of reading on the two display types is very similar in terms of both subjective and objective measures.

The objective tests resulted in a mix data points, with some subjects scoring higher after reading on E-ink and others scoring higher after reading on LCD. The results from the visual fatigue query were fairly close, though the LCD did rate marginally higher. Even the reading speed was virtually identical. In fact, the only major difference was when the test subjects were queried about general fatigue. LCD test subjects reported a higher general fatigue level than did E-ink test subjects, but that could be due to the size and weight of the iPad.

E-ink is often described as being just like reading on paper, and that's why the scientists were surprised to discover that the results were so similar. They were also somewhat surprised because this study contradicted many of the studies listed in the bibliography. It has long been documented that reading on screens is more tiring than reading on paper, and the bibliography cites any number of papers from the past 30 years which prove this is true.

So yes, all those assumptions about reading on screens being bad for you had a basis in fact.  But here's the catch: many of those older papers might not be relevant to how we read in 2012. As the authors point out in the paper, screen technology has improved a lot in the past decade, even more so in the past few years.

What if the reason this study couldn't find a difference in was that the subjects read on an iPad? Even today, that is a high quality screen. What if the subjects in those older studies were affected more by the poor quality of the tech than the tech itself?

If this pans out then it means the screen fetishists were right all along. A higher resolution screen really is better, and each step up in resolution is a boost in the user experience. It's not just marketing hype, anymore; pixels do matter.

image by Bitterjug

80 thoughts on “Study: E-ink is NOT Better for Your Eyes Than LCDs

  1. Interesting results but hard to put too much stock into it with a sample size of 10. I know a lot of people who have no difficulty reading on LCD screens and some who even prefer it. But I also know some who just can’t do it for long periods of time. 10 people doesn’t seem near enough to draw any conclusions.

    1. Pulse width modulation in lcd i led lcd displays causes nervous system fatique – this is the reason.
      Also it is not natural for human eyes to read from the source of light. We read from the reflected surfaces.
      Smoother fonts are good for eyes.

      Reading for hours is not good also when from paper… We are designed to live diversified lifes.

      1. LED and LCD display are good to addict people to use computer that’s reason why e-ink tecnology is not developped for using as screen for monitors. A lot of money is made on top of those addicting tecnologies! Light is addictive! That’s my opinion!

        1. If you have weak retina, not accommodation – E-INK will be much BETTER than LCD/OLED because it doesn’t blast your eyes with direct light.

          Especially if you are working all day long.

  2. I don’t notice a different either way. I’ve never had a huge problem reading onscreen. Yes, reading of any kind for long hours (and I’m an avid reader so I do it for hours on end) tires my eyes. It dries them out. I can’t read white on black comfortably. But other than that, it doesn’t really matter to me if it’s e-ink, my computer or a paperback. Thankfully laptop screens are a lot better these days (resolution and whatnot) because I work on one all day.

  3. I caved in last week and bought a tablet (a Nexus). Using the Kindle app on that, provided the illumination is right, is just as pleasant as using my Kindle 3, but here’s the thing — after an hour or two I mysteriously find myself wanting to swap them. There must be some subtle difference between the screens. It’s good that the subject is now coming under scientific scrutiny.

    The mooted demise of E-Ink may also be postponed (or even cancelled) because of E-Ink’s low power-consumption and the fact that E-Ink devices tend to have fewer onboard distractions.

  4. It would be interesting to see this study done with a much larger sample size and using the new Kindle Paperwhite against the new iPad or Nexus.

  5. I wonder…

    Repeat this test, but now, use a monitor (instead of the Ipad) and an e-ink device which is propped up exactly like the monitor (and this last is very important!) Because that’s one huge difference between now and the last 30 years (beside the resolution, which I also think is very important).

    It’s diminishing, but before the rise of the tablets, whenever people thought about reading from a screen, they envisioned a monitor. And not a device which you could hold in your hand so you could find a comfortable position.

    Me, I’m using both systems with pleasure. Each has its strengths and weaknesses. I never noticed any tiredness after reading on my tablet for longer stretches of time. Unless I used it in a brightly lit environment. And I won’t even try to use my e-ink device in a darker environment as I must start to squint to even read and that’s very tiring!

  6. for me, as much as anything else, it’s a matter of weight. The new eink readers are virtually weightless in my hands. Tablets are quite a bit heavier, and make my hands hurt. I find even my smart phone (a Droid Razr Max) is really too heavy for long use.

      1. Well, the weight may be spread differently due to the way a person holds it. Not that I’m arguing the weight point. I do know several arthritic users in my cozy group love the e-reader they have because hardbacks are too heavy for them to manage without pain. I generally read on my laptop if not my Kindle and oh-boy, the kindle is a vast improvement in weight there!

      2. the screen size of the Droid Razr Max is 1.7 inches smaller than the Kindle’s, so it can fit less words of the same size. Over time, the Droid would tire the reader more.

      3. Now, since the poster you responded to mentioned tablets — perhaps you should have added the weight of some of those, eh?

        Original iPad — 24 oz.

        Oops.

  7. I have a few friends who work in this business and one of them had this comment on the study, which I would think is a good point.

    Doesn’t look like they were comparing apples to apples. You’d have to have the same fonts, same font size, same size device, same resolution (or ability to range from the same to lower/higher resolutions), same lighting conditions, etc. and for good measure I’d throw in a couple scenarios – outdoor reading, indoor reading with adequate light and indoor reading with insufficient light. My take is that LCD reading has gotten much better with higher resolution screens and things like reading with black background/white text, but with screen glare, etc. e-ink is better in normal to bright light conditions. In my humble opini0n.

    1. You’re suggestions make a lot of sense. More and more tablets made these days have incredibly high pixel density while most of the e-ink readers don’t. With scientific testing as many variables as possible must be eliminated to avoid bias results. The testing needs to be done with larger amounts of people and by multiple independent research groups.

    2. Yeah, I would have liked to have seen how well people were able to read on the iPad in sunlight, outdoors. Perhaps they could have added squint fatigue and and “hand-shading” fatigue to the testing parameters.

  8. I say do the test again but strap the subjects into chairs and use an apparatus that forces their eyes open. Have violent and pornographic images pop up on the readers while classical music is playing. Then see what happens.

    1. We believe that the “eye fatigue” found in previous studies may have been caused not by the LCD screen, but rather by the rabid wolverine clawing at the subjects eyeballs.

      We regret this error.

      signed,

      scientists

  9. I always assumed that the eye fatigue caused by LCD screens was because people had the screen set too bright. When the screen is adjusted to the ambient lighting conditions I’ve never had a problem, but I see people reading LCD screens with the light so bright it would hurt my eyes. So perhaps in this test they set the brightness correctly, hence the difference with previous tests.

    1. I always set my screen settings to lowest brightness, and reading on my LCD laptop screen still gives me tired eyes, and after a while slightly blurry vision and even spots for the eyes, plus it feels uncomfortable and makes me tired. I write, edit and read a lot on my laptop screen and these issues worry me and interfere with my productivity, so I am extremely eager to find a good quality e-ink monitor I can use with my laptop keyboard. A tablet screen is a bit too small but I would still prefer that if I could use it with my laptop keyboard, than looking at the LCD screen.

      No colour or funky features are not a problem at all, but the refresh rate, font type, screen size etc needs to be convenient for writing and editing.

      I can not believe this product is nowhere to find yet.

      1. Anna, these are my thoughts exactly! I too have been longing for such a device: a laptop with an e-ink screen, or even a desktop computer with a e-ink monitor. Yes, black and white, yes, even with the less-than-stellar refresh rate!

        This would suit perfectly my regular needs: working a lot with text processor, writing (literature and essays), doing translation work, proofreading for hours. Activities during which I need no distractions (colour, flash animation, videos, music…), just plain text work…

        There are so many professionals who would love to have this alternative to the LCD screen. Writers, academics in the humanities and sciences, editors, proofreaders, even accountants and architects — jobs in which one has to view a screen for hours. Jobs in which the colors on screen are unnecessary and where the refresh rate is irrelevant.

        Someone should invent this screen and it would sell massively to publishing houses, newspaper editorial offices, universities… and individuals like myself.

        Thanks, Anna for bringing this up.

  10. staring at a fucking fluorescent lamp all day is a hell of a lot different from staring at a relatively static field of ink bubbles all day. anyone who says other wise doesn’t live in this place called “reality”.

  11. If you work all day at a computer and have the serious related disorders (inability/delayed ability to focus at a distance, extreme light sensitivity) that can develop over time, then you know it’s the lighting that is to blame. You feel actual pain. You set the brightness as gently as you can while maintaining readibility, but it still hurts. There are eye exercises that help, and you learn to take breaks regularly. Setting a non-white background in applications that allow it helps (as it reduces brightness without affecting readibility). This study should have included people who actually suffer from this, as I do. Testing on people who don’t have the problem to begin with shows… no problem.

  12. One study with 10 people is hardly conclusive. It’s barely even worth mentioning. Once more independent studies have been done and have a larger sample size, then we can start getting some answers.

  13. My eyes get tired in just a few seconds (!!!) after looking at any modern LCD screen of any technology (amoled, ips and so on). However, I can read an average paper for tens of hours without any problem. The difference is huge at least for me.

  14. twaddle. Who paid for this study? Who peer-reviewed the test conditions? We don’t even know that the same fonts and resolutions were used on both devices.

    they had the people read for “a few hours”. A serious study would need to take months, if not years. And it would have to involve people who like to read * a lot * and who are prepared to use a device a lot.

    I read a lot, but I prefer physical books. I have just bought a Kindle Paperwhite and it deffo feels more comfortable on my eyes compared to all other devices.

    I just wish the E-ink idiots would produce better and bigger devices and develop colour. Presumably they need BigCorp to step in with the readies. Why not tablets with E-ink? No doubt economies of scale would cause production costs to drop.

    1. “E-ink idiots” is the best word to describe them! making expensive devices for doing ONLY ONE task which they fail to do properly! i just get headaches more often because of E-Ink devices’ flashing than lcds’ brightness!

      1. That is the best word to describe you..first of all you are deliberately insulting people without knowing what you are talking about, probably because you have never suffered of strong eyes disease like me….due to that, not only i invite you to read the comments here to understand that probably you are alone thinking in that way, but before insulting the others by calling them “idiots”, look yourself at the mirror of your home….thanks to Eink my life has changed forever, finally, after years of eyes pains, i can read digital documents without burning out my eyes anymore….

  15. This study is absurd. I have problems reading articles on an LCD screen. My eyes get really red and tired. However on my kindle I can read for hours at a time.

      1. Changes always come with age. I am 58 years old working in Finance. I have to sit through layers and layers of figures in excel. Unfortunately my tired and aged eyes have not been accustomed well to years of staring at an LCD screen. I would think it might have been different if i were instead staring at figures and letters on paper rather than a bright TV-like source. It just doesn’t feel natural.

        1. In my case, as I’ve gotten older, I’ve found that a LCD screen is easier to read than paper, under the right conditions. I read ebooks off my tablet in a fairly dim room with the brightness of the screen turned down. If I have to read from paper, I have to turn up the ambient light up enough to irritate my eyes. I haven’t tried an eink screen, but I assume it would give me the same trouble.

      2. I sincerely doubt that you spend 10 hours reading on you LCD screen. There’s a lot of glancing away, looking at pictures and scrolling down the screen. It’s not the same as reading a book for hours at a time.

  16. This study doesn’t mention the parameters of the environmental light during the test.

    If you read in closed spaces, in optimal conditions, then there might be no notable difference. But if the light sources around you are varying (as it happens in real life – in the bus, station, on the beach etc.), then the results are completely different, as the LCD doesn’t reflect the outer light and it’s unable to adjust its emitted light to compensate for the variations. This is where the e-ink has a huge advantage, because it reflects the outer light and you’re actually reading in the light of the environment.

    It is a huge difference in reading inside an office or outside in the sun shine. If you try reading from a LCD in place where the light varies and shines from your back, then your eyes will put in a lot more effort than if you read from e-ink in the same conditions.

  17. People saying “e ink idiots” are idiots themselves. Don’t you people understand that compared to LCD technology, e ink is still in its infancy? Think of all of the monochromatic LCD devices you owned before the technology had the ability to be used for displaying complex images. Think of the Timex watch you owned back in 82, think of the calculator you purchased back in 93. You catch my drift? E ink was only in the theoretical stages through the mid nineties. All of the extra years of R&D provided to LCD would give it the obvious advantage. But even more important than than that, the technologies are both so fundamentally different. LCD is the natural choice for moving images and such, whereas e ink excels in the static image department.

    Furthermore, for the past 10 years, LCD has been nearly the only available display technology for so many different applications (think computers, TV, tablets, hell even NASA flight simulators). On the other hand, e ink has been relegated to a single market (e readers). How do you think that will affect the speed of development and improvement?

    Perhaps, given enough time and demand, developers will be able to increase the resolution and refresh rate of e ink to the point where it can support color screens and maybe even motion (although, I would imagine that motion will remain out of e ink’s grasp due to inherent limitations).

    Legal disclaimer:
    This comment was written by a computer analyst who spends many hours of his day using LCD technology to perform his job. I am the owner of an LCD based smartphone, LCD based tablet and e ink based ereader. In my opininion, each technology currently serves its purpose well. If you’ve actually read this far, thank you for your time.

  18. Indeed this study measures eyes strain on a very short period where everybody knows it takes years to damage eyes. Only a study lasting years could be significant here, would show how easy e-ink is for eyes after years not just a day or two !
    E-ink screens are far better for your eyes.
    I tried e-ink on myself… try it on yourself rather than swallow studies made by and for lobbies !

  19. This is an old trick:
    -> Make a study with a small test group.
    If result as desired -> publish in the media
    else -> make a new study

    Repeat ad infinitum or till you get the desired result

  20. I had a kindle 1 and then moved to the Kindle 2 Keyboard and then on to the Kindle Fire HD. The resolution of the Kindle Fire is amazing but after 2 months of use I’ve gone back to my kindle 2. The eink display is so much nicer to read for long periods.

    I ride the train for 2 hours every day and I was unable to focus for that long with the kindle fire hd. With the Kindle 2 I have no problems. Train ride is over before I know it.

    There is also the weight factor. The kindle fire with the case is pretty heavy. The Kindle 2 (without the big leather case with the light) is much lighter. The glare off the screen was pretty bad too on sunny days. I would have to look for a seat away from a window or I couldn’t see anything.

  21. that’s so damn terrific news
    I suffer with eyes since 2 years, I’ve been behind my monitors since 1985 with amstrad CPC
    So i never though it will hapen, but yes, my eyes are now dead. There’s no medecine, be warned.
    I killed it with a 28″ lcd (i changed my LCD like 10 time since 1999)
    I recently bought a pixel QI and a samsung N150, AND IT’S THE SOLUTION
    I don’t get it, LCD just put direct light in your eyes and burn them.

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