Kindle Screens and Your Eyes

Today technology is everywhere and we are surrounded as a result by more and more screens. So much is this the case that many marketing departments around the world are currently looking into how they can take advantage of these ‘background’ screens that are constantly on.

The worry of course is that screens are not completely good for our eyes, and they can cause a little eye strain. At the same time more and more features on these screens – such as greater brightness and 3D depth perception – are taking their toll on our eyes and making it even harder for them to maintain focus. This then is why the Kindle was such a breath of fresh air – a screen that was actually good for the eyes and that you could read to your heart’s content without worrying about eye strain. Then at the same time it’s also very good for the environment and for your energy bill. But how does this work? Why don’t we see more screens like it? And are they really that much better than ‘normal’ monitors?

Why Monitors Cause Eye Strain

The main reason that monitors cause eye strain is that they cause your eyes to have to constantly adjust to different levels of brightness. Your eye achieves this by using tiny muscles to change the size of the pupil and thereby let in more or less light, and normally this occurs gradually throughout the day. The problem occurs when you watch TV or play computer games – particularly in the dark – because the brightness coming off of the television continually changes and thereby forces your eyes to have to adjust to the different levels of light. Rapid editing makes this worse as the scenes swap from dark to light and it can leave you with quite a headache. Of course TVs and computers need to use light to create the images however as this is how the pixels work – they are essentially all tiny bulbs.

The other problem is glare and this is something that makes using computers a problem. This happens when you position the screen in front of a window or another light source and it reflects off of the screen. As you move around that glare changes and you end up again adjusting to different levels of lighting. At the same time though as you are trying to read text over a bright spot of light this then means you are forced to look directly into the light which can cause eye strain too.

To prevent the problems then you would need a screen that didn’t reflect light and that didn’t emit it either – and that is where the Kindle screen is so useful.

How the Kindle Screen Works

The great thing about the Kindle screen is that it doesn’t use light to light up the pixels, but rather ink, or ‘e-ink’ as Amazon call it (hence why the screens are called ‘e-ink’ screens). The ink is then simply arranged on the screen where the pixels are and this creates the image.

The reason this is so good is that it doesn’t require any light in order to light up – and that means that there are no changes in contrast that your eyes have to adjust to. At the same time there’s no glass and the material of the screen is different and less reflective.

But the added bonus is that once the ink is arranged on the screen it doesn’t require any energy to maintain. Because there is no light coming out of the screen there is no change in contrast when the content changes and because there’s no glass there’s no glare or reflection. This all then means that reading a Kindle screen is actually just the same as reading from normal paper. Of course there’s no light coming from behind so that does have the slight downside of meaning that you can’t read in the dark, but then again you can get around this by simply using a reading light – just as you would with any normal book. At the same time it means that no energy is being used and this is why the Kindle can be used for days without running out of battery – it’s only changing the image that requires power and the internet connection.

E-Ink Screens on Other Devices

Other e-readers such as the Kobo also use e-ink technology in their screens, but it will be a while before we start to see e-ink computers and other devices. The reason for this? Well as well as not creating its own light, the e-ink screens also have two other slight drawbacks – one is that they take a long time to change screen and this means that there is no way they could (currently) support video or computer games. The other problem is that they are currently only in black and white – and most people would opt to use a color device and perhaps face a little eyestrain for the majority of their tasks.

Comments 15
  1. There is research on how screen backlights are bad not only for the eyes but also for the nervous system, engaging the brain in a permanent startle effect. (Ref: Chilton Pearce 2012)

  2. I wish I could make this a 4 + 1/2.

    It's very informative, but I would also like to have read the query. Also there is a basic assumption in the article that other devices cause eye strain but Kindle does not. Anecdotally I know many people who find eye strain after using Kindle also.

    1. With the paper white they had eye strain? I’ve had mine for years and no problems when I went to the fire I started to have it.

  3. AWESOME!!! Finally I can prove to my mom that Kindle E books are NOT bad for your eyes. She is like all E books are extremely bad and cause strain. Thx a lot.

  4. Now I understand why some friends experience headaches and/or eye strain when reading on a computer or tablet, not a Kindle. Thank you.

  5. Finally I would just like to know whether reading from kindle is equivalent to reading from a normal book. Yes or no?

  6. Thanks a lot for the article. The convenience of reading from a tablet can be offset by eye damage, but if technology has found a way around this, then the Kindle and the like devices are great choices.

  7. Does this means that kindle paperwhite is equally bad as it is backlit? And we should go for normal kindle device only?

  8. Hi all. Question regarding speed reading and reading on an iphone/iPad vs Kindle.The kindle and our smart-phones – when in reading mode, do they “flicker” i.e. renew their screens all the time? Cf speedreading; Howard Berg – Guinness book of records/speed reading – mentions keeping in mind the interference in the frequency your eyes work on and your screens “flicker”. His conclusion is that people read the same text faster in a book than on a screen. Howard does promote the Kindle I think that is what the “kindle” device differentiates from a computer. The kindle screen doesn’t flicker? Anybody can confirm this? Thy?

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