We’re all guilty of it; we decided to go to bed, get comfy under our covers, but instead of going to sleep, we whip out our phones. “Going to bed” turns into a few more hours of scrolling through Facebook, Instagram, Twitter, Tumblr, Yik Yak, and when we decide it’s late enough to finally sleep, we have trouble doing so. Why does that happen?
The culprit is none other than the glow from electronic devices, especially the blue light they emit. Blue light prevents the emission of melatonin, which is the hormone our body associates with nighttime.
The pineal gland in the brain releases melatonin a few hours before we go to sleep, making a person less alert, as well as making sleep seem more appealing. When enough blue light hits the eye though, the pineal gland stops producing melatonin and, and as a result, hinders sleep, thus compromising circadian rhythms.
How does this happen? Many know that our retinas contain rods and cones, two light sensors that allow us to see colors, detect motion, and use peripheral vision, but the parts of our eye that detect darkness and syncs our circadian rhythms are called intrinsically photosensitive retinal ganglion cells, or ipRGCs.
ipRGCs were discovered in 2002, and, according to the Washington Post, “They are the body’s way of sending ambient light information to the master circadian clock, a huddle of nerve cells in the brain,” which then tells the pineal gland to either produce or not produce melatonin. ipRGCs are very sensitive to blue light, so when we use our electronic devices at night, it messes up our production of melatonin and circadian rhythm. This prevents us from falling asleep.
With that being said, if you’re looking for a good night’s sleep, turn off the phone, turn off the laptop, and turn off the tablet. The less these devices are used before you go to bed, the better your sleep will be.