Fourth Industrial Revolution

The science behind why you shouldn't look at your phone before you sleep

People browse their phones as they wait in line to buy the new iPhone 7 smartphone outside an Apple Inc. store in Los Angeles, California, U.S., September 16, 2016. REUTERS/Lucy Nicholson - RTSO2RT

Smartphone light can make it harder to fall asleep, leading to serious health problems Image: REUTERS/Lucy Nicholson

Kevin Loria
Writer, Business Insider
Skye Gould
Senior Graphic Designer, Business Insider

The designers of our smartphones, tablets, and laptop screens have been able to create incredibly powerful lights. These screens glow bright enough to be seen during a sunny day. At night, they're so strong that they've been compared to a "little window" that daylight can peer through.

That's why looking at your phone at night is a terrible idea.

Our bodies naturally follow a cycle that allows us to stay awake and alert during the day and helps us get essential rest at night. But when we look at these screens as we're getting ready to sleep, our brains get confused. Bright light can make the brain think it's time to stop producing melatonin, a hormone that gives your body "time to sleep" cues.

By disrupting melatonin production, smartphone light can disrupt your sleep cycle, almost like an artificially induced jet lag. That makes it harder to fall and stay asleep — which could lead to serious health problems.

Image: Business Insider

To combat this problem, app designers have created programs like f.lux and Apple's Night Shift mode, which adjust the light tones emitted by screens at certain times of day to remove bright blue light from the display. Many users say the orange tint these apps give feels less harsh on the eyes. But while some research indicates that dimmer light may improve sleep, more study is needed on the topic.

Even if such changes do prove to be helpful, experts say that many other things we do with our phones are also not conducive to sleep. If you're trying to get ready for bed and a late night work email pops up, that might wreck your sleep even more than shutting down your melatonin production.

Have you read?

If you can bring yourself to do it, your best bet is to steer clear of screens before you fall asleep. At the very least, try to keep them out of your bed.

Don't miss any update on this topic

Create a free account and access your personalized content collection with our latest publications and analyses.

Sign up for free

License and Republishing

World Economic Forum articles may be republished in accordance with the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Public License, and in accordance with our Terms of Use.

The views expressed in this article are those of the author alone and not the World Economic Forum.

Stay up to date:

The Digital Economy

Related topics:
Fourth Industrial RevolutionHealth and Healthcare Systems
Share:
The Big Picture
Explore and monitor how The Digital Economy is affecting economies, industries and global issues
World Economic Forum logo

Forum Stories newsletter

Bringing you weekly curated insights and analysis on the global issues that matter.

Subscribe today

Why we must overcome fragmentation to optimize AI for the benefit of all

Christian Klein

January 15, 2025

How collaborative partnerships pave the way for breakthroughs in quantum-centric supercomputing

About us

Engage with us

  • Sign in
  • Partner with us
  • Become a member
  • Sign up for our press releases
  • Subscribe to our newsletters
  • Contact us

Quick links

Language editions

Privacy Policy & Terms of Service

Sitemap

© 2025 World Economic Forum