To the way we read today, e-readers are as fundamental a change as print must have been at one time to people who read off scrolls. Amazon's Kindle is that company's top seller, and iPads are flying off store shelves at the rate of about a million a month; of all the changes that have come by to affect the way we interact with the printed letter, there is nothing that could quite match what the e-reader has been doing. The concept of dispensing with books for a single screen with hundreds of books in its memory is so new that no one is even sure yet what kind of screen is best for the purpose - a proper backlit screen as on the iPad, or an unlit reading experience such as is to be had with the e-ink screens preferred by the Sony Reader and the Amazon Kindle - you know, to simulate the feeling of looking at actual paper. And no one knows which one of these would be the better choice in keeping eye strain and other eye problems away.
It has to occur to anyone who spends hours curled up with one of these, how contrary an e-book reading experience is to the disapproving warning our mothers had whenever they found us close to the screen of any kind: "Don't do that unless you want to go blind!" Maybe we never wanted to take our mothers at their word, but there is no denying that there is a certain amount of logic to it - the fear that looking too closely at the screen can't be that good for your eyes. Seeing that the market is still trying to make up its mind which way to go with e-book reader technology, perhaps we might put a little thought into it too to keep out any chances of eye problems later.
To start out, the medical opinion goes somewhat against what mom had to say: they feel that pressing your nose to the reader and looking at it cross-eyed sn't really going to hurt your eyes. In fact, sitting that close to a television set, even the standard picture tube kind won't ever have sent you to braille school. There are some likely problems with getting your entertainment in such an enthusiastic way that could tire your eyes out; but there is nothing about the screen and what comes out of that per se that would lead to it. When it comes to the e-readers, the answer isn't quite cut and dried for which type of readers prefer to keep out the eye problems.
To begin with, regular paper is certainly the most pleasing to the eye. The texture of it, the way it reacts to different kinds of light, are all parts of the reading experience that glass screens of any kind could never quite replicate. But that is only if you're reading off high-quality paper. Electronic readers can easily bring you a more pleasing reading experience than with cheap newsprint or romance novel paperbacks. With e-readers, how tired your eyes become depends on your reading environment. E-Ink of the kind in the Kindle has the problem that it is typically quite low contrast. The difference between the letters in the background screen color isn't that great. So while it would be very pleasant to read in brightly lit surroundings, in dim ones, you could strain your eyes - because there is no artificial lighting built into these screens. Standard LCDs such as those on the Apple iPad have great lighting and viewing angles, but they would not do so well in brightly lit surroundings that would cause screen reflections and tire your eyes out again. How do eye problems come into play in these situations then?
Our eyeballs are held in place and moved in concert with astonishing accuracy, by a series of tiny muscles all round the eyeballs. It doesn't really matter to these muscles what it is that you're reading off, paper or screen. When they keep moving your eyes around and holding them tense and alert, they tend to get tired after while. Just imagine, for each block of words your eyes must move and read, your muscles must make a couple of jerky movements to keep up. Depending on how fast you read, that would be about 15,000 little synchronized moves in an hour. Perhaps the secret to keeping eye problems away with e-readers would be more about letting your eyes rest 10 to 15 minutes every hour, than about making the right choice in the kind of screen you get.
But perhaps mom does deserve a certain amount of credit for her admonition. The screens we grew up with when we were young, say 10 years ago or longer, were a lot less sophisticated than the ones we have now. They refreshed no more than 60 times a second; that kind of flicker can undoubtedly cause a bit of eye strain and eye problems on top of that. Today's screens refresh at twice that rate - that's faster than our eyes are able to see to be able to tell any difference. Basically eye problems don't come out of using the wrong technology altogether. They come from using the wrong habits with the right technology.