I used to read actual books, then on my iPhone 3G before I got an e-reader. I have high myopia and astigmatism along with a lazy eye, so it's great to be able to read for long periods without squinting by the end of it.
I have WhatsApp and Facebook on my phone and can spend hours on them (and my eyesight just worsened over the past 6 months because I got lazy with carrying my Nook; I exchange a few hundred messages daily, oops?) so an e-reader is really helpful in combating boredom without destroying my eyes.
