title_body: Is reading ebooks in "Night" mode better for eye health? Many e-book reader programs (at least on Android) like Cool Reader or FFBReader offer the  "Night" reading mode - basically, reverting from usual dark-text-on-light-background to light-text-on-dark-background.
  
  Are there any studies showing whether there are benefits or downsides to one's eye health when reading books in "night mode" vs "normal mode" at night (low light) or during day (plenty of light)? 
  
  Ideally it would cover different display types, but personally I'm especially interested in ~5" LCD and AMOLED displays as on recent flagship Android smartphones.
upvoted_answer: I found this article which explains how our body reacts to these LED devices (including ereaders). Near the end of the article, it says that programs that reduce the amount of blue light do actually aid you in getting a better nights sleep. 
  
  So, to summarize the article; blue light is what causes you to have a bad nights sleep after using a LED device (including ereaders). So, in order to reduce the blue light, you need to get rid of the bright colours. Programs for your computer, and night mode for your tablet do this effectively. Of course, this isn't a 100% solution, but it does help.