Light-emitting devices, including cellphones and yep, the iPad, tell the brain to stay alert. Because users hold those devices so close to their face, staring directly into the light, the effect is amplified compared with, say, a TV across the room or a bedside lamp, said Frisca Yan-Go, director of the UCLA Sleep Disorders Center in Santa Monica.
I missed this the first time around ... score for e-ink?