I have a Paper White, as well. I can't imagine the light, when at its dimmest setting would be more trouble for sleep than any LCD thing. And, in fact, soon aft

I have a Paper White, as well. I can't imagine the light, when at its dimmest setting would be more trouble for sleep than any LCD thing. And, in fact, soon after I got a Nexus 7 and starting reading with it more often than my Kindle (using Twilight to redden and dim the screen dramatically and using the Kindle app in black background mode), my sleep schedule has kinda gone to hell. It's 3AM here, and I'm probably two hours from sleeping. There are confounding variables (winter always screws me up as I get Seasonal Affective Disorder something fierce), but still, now that I'm thinking about it, I think I'm gonna go back to reading on the Kindle before bed and see if it improves my sleep situation. The Nexus certainly hasn't helped. For reference for those who don't have a Paper White; when at its dimmest setting, it is probably less than the ambient light in the room from neighbors porch lights and street lights. It is almost completely dark, and looks like an older non-lit Kindle in any room with lights on. I do wish it could turn off completely, however.