Comment Total integrated light (Score 1) 179
The paper suggests that light prevents us from sleeping well, but does an e-reader emit more light than a reflective paper book with an ambient light source? It's hard to believe that it does; a typical bedside lamp is a few tens of watts (incandescent equivalent) while a phone or small tablet is in the ones.
Even if this was real science, people who read for four hours before going to sleep are an odd group to study. In that group a 10 minute difference in falling asleep probably depends more on how much they enjoy the book than environmental factors. We could just as easily argue that transmissive book readers engage people better than their reflective counterparts.