Why Your Smartphone Won’t Let You Sleep by John Kell @FortuneMagazine November 16, 2015, 3:37 PM EST E-mail Tweet Facebook Linkedin Share icons A London-based researcher reportedly says smartphone makers should consider adding an automatic “bedtime mode” that would reduce light intensity and make it easier for users to sleep. Professor Paul Gringras of Evelina Children’s Hospital in London has said device manufacturers need to show more “responsibility” when it comes to making future models of smartphones, tablets, and e-readers, BBC News reports, Gringras’s research concluded that the type of light used in light-emitting devices produced today uses emissions that are “likely to cause the most disruption to sleep,” as they most effectively suppress melatonin and increase alertness. Thus, Gringras says that “brighter and bluer” isn’t always better—at least when it comes to sleep. The professor believes that future software could be better optimized when the smart devices are used at night. He says an automatic “bedtime mode” should shift blue and green light emissions to yellow and red—which would reduce backlight intensity.