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.
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.
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.
https://www.weforum.org/agenda/2017/07/heres-how-the-light-from-your-sma...