Published research in the Proceedings of the National Academy of Sciences suggests that using a light-emitting electronic device in the hours before bedtime not only makes it harder to fall asleep, but it affects how sleepy you are the next day and your overall health.
Researchers from Brigham and Women’s Hospital in Boston, Massachusetts, analyzed 12 study participants for 2 weeks. Participants read on an iPad for 4 hours before their bedtime for 5 straight nights then, repeated the process with printed books. For some of the participants, the order was reversed, starting with printed books then moving on to iPads.
The iPad readers were less sleepy in the evenings, took longer to fall asleep at night and spent less time in the REM sleep phase. Additionally, they had lower levels of the sleep hormone melatonin, their circadian rhythms were pushed back by one hour and they found themselves less alert in the mornings, even after 8 hours of shut-eye.
According to Dr. Charles Czeisler, chief of the BWH Division of Sleep and Circadian Disorders, overall we’ve been sleeping less with a decline in quality over the past 50 years. “Since more people are choosing electronic devices for reading, communication and entertainment, particularly children and adolescents who already experience significant sleep loss, epidemiological research evaluating the long-term consequences of these devices on health and safety is urgently needed.”
iPads were used in the study, but it’s important to note that the researchers measured all other blue light-emitting devices, including smartphones, laptops, other e-readers, and LED monitors. The activities you perform before bed have a huge impact on your snooze.