Negative Effects of Screen Time on Sleep

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Read about the growing evidence that suggests using a computer or phone before bed can disrupt your sleep, from the experts here at RMI. Read our blog, “Negative Effects of Screen Time of Sleep.”

By Vincent Giampapa MD

It’s recommended that adults need between 7-8 hours of sleep per night. Within the time that we sleep, there are 4 sleep stages that our bodies cycle through approximately 4-6 times during the night. Without 90 minutes in each of these stages, you can still wake up feeling tired. The U.S. seems to have a serious sleep deprivation problem from a combination of poor sleep quality and short duration of sleep. In fact, in a recent poll by the Sleep Foundation, it was found that Americans feel sleepy 3 days per week on average. Additionally, the Centers for Disease Control and Prevention (CDC) reports that about 35% of Americans sleep less than 7 hours per night. This can deeply affect quality of work, relationships, mental focus in school and more. What’s the reason behind Americans sleeping less? Screen time has been shown to interfere with our ability to fall asleep and have quality rest. Staring at that large screen on your dresser or the smaller device in your hand definitely affects your slumber, and we’ll outline how screen time affects sleep below.

What Happens In Your Brain When You Have to Deal with the Negative Effects of Screen Time

Your brain consists of both gray and white matter that contribute to cognitive performance and functionality. Gray matter is found in the tissue on the surface of the brain and helps control memory, emotions and movement. White matter is found in deep tissues of the brain and is responsible for internal brain communication. Having a healthy balance of both matters improves brain function and sharpness. Increased screen time before bed has been proven to restructure your brain by lowering levels of gray matter and causing issues with the brain’s white matter functionality. This rearrangement causes poor cognitive performance and in turn, lack of quality sleep. Exciting device use like online gaming can increase heart rates and brain stimulation. Along with the mental stimulation from the activity on your device, screen time can also keep you awake by causing a physical strain on your eyes and body. Overexposure to blue light devices can damage your retina and cause discomfort when trying to fall asleep. Researchers at Brigham and Women’s Hospital (BWH) found that using a blue light-emitting screen device (such as a smartphone) shortly before bed adversely impacts overall health, alertness, and the circadian clock. Anne-Marie Chang, PhD, corresponding author, and associate neuroscientist in BWH’s Division of Sleep and Circadian Disorders noted she and fellow researchers found that “the body’s natural circadian rhythms were interrupted by the short-wavelength enriched light, otherwise known as blue light, from these electronic devices.” Using blue-light devices suppresses the secretion of melatonin, a hormone released from the pineal gland overnight to control your sleep-wake schedule. As a result, it takes your body much longer to feel tired and delays bedtime significantly. Screens also stimulate parts of the brain that make us feel alert, raise our body temperature and heart rates. This makes it difficult to stay asleep and feel well-rested.

Does Blue Light Keep You Awake?

Our bodies have a natural circadian rhythm, or internal clock, that deeply impacts our awake and sleep schedules. Our circadian rhythm tells us that when it is light outside, it is time to wake up, and when it is dark, it is time to wind down and sleep. Blue light from our devices mimics the light exposure from outside and confuses our internal clock. Since our computers, cell phones, tablets and other devices that we use on a daily basis emit blue light, this is directly impacting our circadian rhythm and preventing our bodies from falling asleep. A study by Harvard Medical School looked at the biological effects of using an e-reader that emits blue light in the hours before going to bed. In this study, they found various concerns from the use of devices before bedtime:
  • Prolonged time to fall asleep
  • Delayed circadian rhythm
  • Suppressed levels of melatonin
  • Reduced amount of REM sleep
  • Reduced alertness in the morning
These results are fairly alarming, as it shows that the screens we so often use nowadays are having a negative impact on our sleep time and quality of sleep. Charles Czeisler, PhD, MD, FRCP, and chief of Brigham and Women’s Hospital’s Division of Sleep and Circadian Disorders notes that there has been a decline in average sleep duration and quality in the past 50 years, and attributes this decline directly to electronic devices emitting blue light. Below is a chart that shows the decline in average hours of sleep over the years. The negative psychological consequences of using screens are profound. One study found that humans suffered from low self-control, difficulty making friends, emotional instability and inability to complete tasks from just half a day of screen time. Furthermore, high use of devices from 14-17 year olds showed higher diagnoses of depression. The negative effects of screen time on our population goes far beyond sleep.

What About Green Light and Sleep?

Similar to blue light, green light helps manage your circadian rhythm. Green light emitted from cell phones, tablets and computers can disrupt your internal clock and impact sleep time.

How Long Before Bed Should You Turn Off Electronics?

Though everyone’s circadian rhythm is different, shutting down electronics about 2 to 3 hours before bedtime is a safe suggestion to follow. This means fighting the urge to power up social media or turn on Netflix before your head hits the pillow. There are plenty of other activities to try before bed to avoid screen time.
  • Read a book. Don’t let your bookshelf collect dust; find a new favorite author and read an old-fashioned paperback before bed.
  • Draw. Get those creative juices flowing and try to draw, doodle, or even color. You don’t need to be an artist to explore your creative side.
  • Write in a journal. Journaling is a great way to recount fond memories and practice gratitude to help you end the day on a high note.
  • Take a soothing bath. Light a candle, pour some Epsom salt into the bath, and ease into your evening.
  • Listen to music. Put on slow, soothing music that’ll help you wind down and feel relaxed.
  • Practice self-care. Wash your face, put on a facial treatment, or paint your nails. Investing in your physical health and wellness will leave you feeling rejuvenated before bed.
  • Prepare for the day ahead. Meal prep for this week’s lunches, set out your clothes and items you’ll need, and get organized so you can feel prepared for tomorrow.
  • Stretch. It’s proven that resistance exercises (like stretching) can improve symptoms of insomnia. This gentle physical activity can help reduce stress, improve circulation and help you feel rested.
  • Meditate. Quiet your mind and body through thoughtful meditation. This mindful activity will help calm your thoughts and help conclude your day.
If avoiding screens is difficult because your work requires you to work late hours on an electronic device, try wearing blue light blocking glasses like Horus X Glasses. You can also use apps that allow you to adjust the screen brightness to block blue light like the f.lux app. Apple devices have Night Shift capabilities that adjust colors of your screen display to warmer colors after dark. Although avoiding screens altogether is the most effective strategy, making these slight changes may help you achieve better sleep. References