[quote=@Haeo]
The first thing to come to mind after reading this was... why would you read a book in a low light environment?  But... yes, trying to read a sheet of paper in the dark is harder than reading a glowing screen in the dark.  Some of these studies and manufacturer claims just make my brain hurt.
[/quote]

Some people like to read before sleeping. Keeping the bedroom light dim calms their body down.