I've personally had sleep issues for years now... Basically, I have a difficult time falling asleep and staying asleep. I do spend quite a bit of time on the computer at night and do use an eReader to read many books.
I did come an interesting article posted on the New York Times's blog titled How E-Books May Disrupt Your Sleep by Nicholas Bakalar. In the article, Bakalar writes the following:
Compared with a printed book, a light-emitting e-book decreased sleepiness, reduced REM sleep (often called dream sleep), and substantially suppressed the normal bedtime rise of melatonin, the hormone that regulates the sleep and wake cycle. The e-book users took longer to fall asleep and felt sleepier in the morning.
“Much more has to be known about the kind of impact these devices have on our health and well-being,” said the lead author, Anne-Marie Chang, an assistant professor of biobehavioral health at Penn State. “The technology moves quickly, and the science lags.”So, perhaps some of my sleep issues are related to reading books on an electronic devices at night near bed time!?