Sleep better with a real book

Reading a book on a tablet or e-reader before bedtime disrupts your sleep. Harvard researchers found that the screen´s blue light negatively influences the secretion of melatonin and disrupts sleep patterns. A two week study where participants read a real book for five consecutive nights followed by reading on the iPad (or vice versa) confirmed that those reading on the iPad took 10 minutes longer to fall asleep and their REM sleep was shorter. The blue light seems to be the cause. The research doesn´t mention the effect of changing the background colour.