Evening use of light-emitting electronic devices such as tablet computers can induce delays in desired bedtimes, suppress secretion of the sleep-promoting hormone melatonin, and impair next-morning alertness, according to a study led by Dr. Jeanne Duffy of Brigham and Women’s Hospital and Harvard Medical School. Using light-emitting tablet computers in the late evening can postpone our decision to go to sleep, and make us more sleepy the next morning....
