When we use electronics in the dark, before bed, like phones or iPods, why is it bad for us?

Question: When we use electronics in the dark, before bed, like phones or iPods, why is it bad for us?
- Keywords:
  dark,
  ipods,
  phone,
  sight
Asked by jodiebowey23 to Damien, Rachael, Simon, Suzi, Tim on 15 Jun 2011.
- Suzi Gage answered on 15 Jun 2011:
  
  Hi @jodiebowey23
  
  I don’t think it’s bad for you to use them in the dark, but if you use them just before you go to sleep it can overstimulate you and make it really hard to go to sleep. If you want to wake up and feel refreshed I find it’s best to avoid TV or ipod for at least an hour before bed. But that’s not science, that’s just my personal opinion.
  
  Anyone else know the science?? 🙂

Question: When we use electronics in the dark, before bed, like phones or iPods, why is it bad for us?