Reading a book can help you drift off to sleep, but you've always been told to power down your electronics at least 20 minutes before you'd like to go to sleep - a confusing proposition if you've eschewed paperback books in favor of your iPad.
A new study confirms that you should, in fact, stack your nightstand with books rather than your tablet. The small study found that two hours of exposure to the light from your tablet or laptop reduced melatonin, a hormone that helps regulate your sleep cycle, by 22 percent. Melatonin suppression can lead to disruptive sleep and changes in your circadian rhythm; that's why it's important to avoid things like artificial light that can alter your body clock. So if you're used to reading a few chapters before bed on your tablet and are finding it hard to get quality sleep, switch to a good old book instead. If you can't part with technology, e-ink readers like a text-only Kindle or Nook are fine to use since they don't emit light.