Filtering Blue Light to Get Better Sleep

Apps and Software

Photo By via Wikimedia Commons


Many people nowadays are glued to their phone up until bedtime. Not only can phones be a distraction to activity, they can also be a hindrance to getting a good night's sleep.

To address this problem, several apps have been developed to filter out blue light produced by phones, tablets, and computers, such as the iPhone's Night Shift. However, there still haven't been enough studies to confirm just how effective these apps are.


According to Lisa Ostrin, an assistant professor at the University of Houston College of Optometry, people are exposed to a large amount of blue light when using their mobile phones and tablets, especially at bedtime when they hold their phones very close to their faces. Photoreceptor cells in the eye are tricked by this light into thinking that it is still daytime, inhibiting the release of melatonin, a hormone that helps us sleep.

In a study published in the journal Ophthalmic & Psysiological Optics that Ostrin was part of, 21 people used special glasses to filter out blue light in the evening. The melatonin levels in the participants increased by 58 percent two weeks later, and by that time, they were getting better sleep.

While blue light-filtering apps don't work as well as the glasses used in the study, Ostrin recommends using them, saying that they could still help.

On the other hand, Southern Methodist University's Brian Zoltowski no longer uses his iPhone's Night Shift app. When he was still using the app, he found that he saw everything in a shade of orange during the evening. It didn't help him sleep at all.

According to Zoltowski, a filtering app alone might not be all that effective, as blue light comes from other sources as well, such as indoor lighting, street lights, and car headlights. However, those with sleep problems could add a filtering app to the measures they take to get a good night's sleep. Better yet, he recommends avoiding screens altogether near bedtime.

At least one study supports his suggestion, reporting that people fell asleep faster when they read from a printed book than when they read from an e-book.