Not all light is created equal, and our bodies have evolved to register certain frequencies and colors of light as more energizing.
“When our eyes see light in the teal to green to blue spectrum, it’s daytime. It’s the color of sunlight through seawater… It’s the color of the natural world,” Grandner explains. It’s also, unfortunately, the color of our phone screens.
Even if the rest of your sleep environment is pitch-black, looking at your phone in bed can still send a signal to your body that it’s earlier in the day than it actually is.
“Even though the amount of light coming out of them isn’t huge, it’s all going right into our eyes,” Grandner says as to why phones, in particular, are so harmful to sleep compared to electronics like TVs that tend to be farther from our faces. “It could be sending a daytime signal at the wrong time.” Depending on what you’re looking at, your phone can also trigger the stress hormone cortisol, further delaying sleep.
The most surefire way to resist the urge to scroll is to keep your phone out of sight in another room.