Technology, Blue-Green Light and The Impact on Healthy Sleep

technology light

Advancements in technology over the past few decades have made it possible for people to be even more connected. Today, working professionals check emails at all hours of the day and even toddlers play games or watch movies on their smart devices. Between our work and our entertainment, the average adult spends approximately 11 out of 18 waking hours per day in front of a screen, according to Nielsen. What’s more, a recent Time Magazine article explained the phenomenon this way: “Device by device, service by service, we have built over the past decade a world in which an amazing amount of what we do is recorded by our personal devices[…]” On the surface it seems innocent enough, however, with increased exposure to digital screens, there’s growing concern surrounding the blue light these electronic devices emit and the effect it is having on the sleep and overall health of the population.


The National Sleep Foundation reports that almost 95% of people use smartphones before attempting to fall asleep. Light emitted by smartphones and other devices can signal daylight to our brains and in particular blue-green wavelengths are scientifically proven to accentuate our drive for wake while simultaneously shutting off our drive for sleep. Here in lies the problem; using blue-green light emitting devices during sleep hours not only suppresses our sleep, it triggers our central nervous system centers for wake. In one of the most ancient parts of our brain, just above the crossing of the optic nerves (or optic chiasm) lies a small bilateral cluster of cells referred to as the Suprachiasmatic Nucleus (SCN). These neurons get direct light cues primarily from blue-green sensing neurons in the retina and then activate to reboot our wake and sleep rhythms every day. With or without light, our SCN naturally generates and orchestrates our personal internal brain and body clock, known as our circadian rhythm. Each of us have a different circadian rhythm based on our genetics, our age and our health. While most adults live with a 23-25 hour circadian rhythm, a few have longer or shorter circadian periods that result in early morning larks, and late night owls. Since most all adults require between 7-9 hours of uninterrupted quality sleep each night to recover mentally and physically, the effect of blue-green light emitting from their electronic devices can can have a major impact on both sleep quantity and quality. When our reliance on electronic devices during the day bleeds over to the night, it is not only distracting but also a biological impediment to sleep health.


Poor sleep is a growing crisis in the U.S. Approximately 45% of Americans report sleep issues on night-to-night basis, and one-third of the population get less than 7 hours of sleep per night. As the country begins to operate on less sleep, human performance and brain function are affected. For instance, when sleep deprived, we are less capable of thinking analytically, solving problems, or being creative. This is due to the fact that sleep deprivation selectively impairs regions of our frontal lobe that are responsible for higher cognitive abilities such as executive function, creative problem solving, as well as focus and attention. As a result, workplace accident rates increase, errors occur more frequently, and productivity levels decline.

The battle happens at night when we wrestle with the decision to either send out a late email or go to sleep on-time. For most people, the email emerges as the victor. But the reality is that disrupting our circadian rhythm with blue-green light impacts not our ability to fall and stay asleep, but more importantly we lose the essential recovery that sleep provides for our cognitive and physical performance. For those in the midst of the battle, there are now technologies that can help combat the effects of blue-green light so our bodies can transition naturally into sleep.


Recently, Apple launched an update to its software which reduces blue-green wavelength emissions during sleep hours. This feature enables automatic shifting of the display color spectrum of its devices to a warmer orange/yellow wavelength during the evening and throughout the night. These sorts of enhancements are important as 60 million people in the U.S. (many of them in the workforce) continue to suffer with sleep and circadian rhythm problems. As emphasized in our recent article, Humans vs. Machines, unlike mechanical devices, we require consistent, high quality sleep in order to perform efficiently. Human “maintenance” occurs naturally during sleep, and without it our physical and mental functions, including vitality, mood and memory will degrade over time. By proactively disconnecting yourself from technology before bedtime, you can begin to restore your own brain and body functions in order to live more productive, resilient, and happy life.

FusionHealth is the leader in providing technology enabled sleep health solutions for self-insured employers to deliver lasting results to their employees, their families and their companies.

1. Time
2. Nielsen
3. Apple
4. Scientific American
5. Sleep Foundation
6. CDC