We examine a paper that finds sleep disruption from using tablet computers (as compared to reading a book in dim light). How much should we be worried about the effects of screens on a good night's sleep?

There's good reason to believe that blue light is the main culprit -- recently discovered receptors in the eye that respond to blue light directly connect to brain areas implicated in sleep regulation. We lay out the case....

Papers:
"Evening use of light-emitting eReaders...."
"Melanopsin: photoreceptors, physiology and potential"