In the study, 21 people put on special glasses after sunset each day to filter out blue light. Ostrin was part of a team that showed this in a study published this summer in the journal Ophthalmic & Physiological Optics. 'But when we have all this artificial light on, it's tricking those photoreceptors into thinking it's still daytime.' 'Normally when the sun goes down and the lights turn off, our body releases melatonin, which helps us get a nice restful sleep,' Ostrin says. Without a filtering app, cellphones and tablets expose users to an alarming amount of blue light, she says, 'Especially as people are lying in bed and have their screens just a few inches from their face.'Īnd all that blue light prevents special photoreceptor cells in the eye from triggering the release of a sleep hormone, she says. And every iPhone comes with an app called Night Shift that lets you filter out blue light. My first call is to Lisa Ostrin, an assistant professor at the University of Houston College of Optometry. So I phoned a couple of scientists who study the link between blue light exposure and sleep. There haven't been any big studies to answer that question.

In fact, there are now lots of apps that promise to improve sleep by filtering out the blue light produced by phones, tablets, computers and even televisions. If you're losing sleep over the blue light coming from your phone, there's an app for that. (Artur Debat/Moment Editorial/Getty Images) If you're regularly checking your phone at night in a dark room, you're probably tricking your body into thinking it's still daytime.

Is there a blue light app for iphone