Is the blue light from your phone really ruining your sleep? Here’s what the experts say

The message is across: blue light is bad for your health. Where is it? Experts will tell you: blue light at night can reduce the quality of your sleep. That’s part of why the blue light-blocking glasses industry could reach $5 billion over the next decade. But experts also say that blue light is good for you and that your phone may be keeping you up at night for reasons other than light exposure.

The sun is the main source of blue light. Humans are programmed to wake up when daylight, rich in blue, hits their eyes. Oxford scientists say that light entering the eye helps synchronize the body’s internal clock with the external light-dark cycle of day and night. Blue light at night can disrupt our systems, affecting circadian rhythms that regulate appetite, hormone release and sleep. But it’s not just the light that’s the problem. Melanopsin, the eye protein that helps the brain know whether it’s day or night, responds most strongly to blue light, but also responds to other types of light.

So, blaming your phone’s blue light for poor sleep is an oversimplification. A Portuguese study found that exposure to blue light from common digital devices was lower than what people receive from natural daylight, making bedtime and bedtime habits more important than exposure to blue light alone. Device brightness, time of day, duration of use, and mental stimulation all affect sleep. There are steps you can take to improve your sleep, even if you refuse to give up your nightly session of that iPhone word game that’s harder than Wordle.

Reducing blue light in bed can help you get more rest, but the impact varies depending on how you do it. A comparative study found that night mode on your device and blue light glasses reduce exposure to short-wavelength light, but night mode is more effective. However, reducing blue light is not the only way to improve sleep quality. A Saudi medical study found that general use of a device before closing one’s eyes can decrease sleep quality.

In a University of Washington study, a comparison between people who avoided screens before bed and screen users at night showed that screen users had a 33% higher rate of poor quality sleep. You already know the basics of getting a better night’s sleep, like hiding your phone in another room and tuning out the world at night, but you should also consider putting your phone down at least half an hour before bed.

Researchers at the University of Southern Mississippi say you need plenty of bright light during the day to regulate circadian rhythms and that morning sun can strengthen your internal clock. Meanwhile, a University of Texas study recommends taking a shower before bed. This will increase your body temperature for a short time. Then your body cools down, signaling the brain that it’s time to sleep.