1: The date was September 4th, 1882. The world was about to change forever.
At 257 Pearl Street, not far from the Brooklyn Bridge, Thomas Edison’s power-generating station began supplying electricity to customers in the First District, a one-quarter square mile area in New York City.
“For the first time, the human race had a truly scalable method of unbuckling itself from our planet’s natural twenty-four-hour cycle of light and dark,” writes Matthew Walker in Why We Sleep: Unlocking the Power of Sleep and Dreams. “We, and not the rotating mechanics of planet Earth, would now decide when it was ‘night’ and when it was ‘day.'”
There has been a corresponding decrease in the amount of sleep we get: from around 10 hour’s pre-Edison to about 7 hours today.
We are chiefly visual creatures, notes Matthew. “More than a third of our brain is devoted to processing visual information, far exceeding that given over to sounds or smells, or those supporting language and movement. For early Homo sapiens, most of our activities would have ceased after the sunset. They had to, as they were predicated on vision, supported by daylight.”
Before Edison, and before gas and oil lighting, when the sun set, our brains would naturally unleash vast quantities of melatonin signaling to our bodies and brains that it was time for bed. “Appropriately scheduled tiredness, followed by sleep, would normally occur several hours after dusk across our human collective,” Matthew writes. “Sleep in modern humans is delayed from taking off the evening runway, which would naturally occur somewhere between eight and ten p.m., just as we observe in hunter-gatherer tribes. Artificial light in modern societies thus tricks us into believing night is still day, and does so using a physiological lie.”
When we do finally turn off the lights to fall asleep, it takes time for the “rising tide of melatonin” to take effect. For some, artificial nighttime light mimics sleep-onset insomnia, the ability to fall asleep within twenty-five minutes.
2: In 1997, another new invention, blue light-emitting diodes, or blue LEDs, made falling asleep even more challenging. Blue LED lights power our laptop screens, smartphones and tablets. They have lower energy demands and longer life spans than incandescent lamps. But, when it comes to our sleep, there is price to be paid. “Evening blue LED light has a more harmful impact on human nighttime melatonin suppression than the warm, yellow light from old incandescent bulbs,” Matthew explains.
9 out of 10 American adults regularly used a portable electronic devise within 60-minutes of bedtime, a recent research study showed – which has “a very real impact on your melatonin release, and thus ability to time the onset of sleep,” Matthew notes. One study showed using an iPad for two hours prior to bed blocked the rising levels of melatonin by a significant 23 percent.
“A more recent report took the story several concerning steps further. Healthy adults lived for a two-week period in a tightly controlled laboratory environment. The two-week period was split in half,” writes Matthew; “(1) five nights of reading a book on an iPad for several hours before bed, and (2) five nights of reading a printed paper book for several hours before bed.
“Compared to reading a printed book, reading on an iPad suppressed melatonin release by over 50 percent at night. Indeed, iPad reading delayed the rise of melatonin by up to three hours, relative to the natural rise in these same individuals when reading a printed book,” Matthew notes. “Unsurprisingly, individuals took longer to fall asleep after iPad reading relative to print-copy reading.”
3: The bigger question was: would reading on an iPad also change the quality/quantity of sleep beyond the timing of the melatonin?
Unfortunately, it did in three “concerning” ways, Matthew shares: “First, individuals lost significant amounts of REM sleep following iPad reading. Second, the research subjects felt less rested and sleepier throughout the day following iPad use at night. Third was a lingering after effect, with participants suffering a ninety-minute lag in their evening rising melatonin levels for several days after iPad use ceased—almost like a digital hangover effect.”
What we can do is practice what philosopher Brian Johnson calls “a digital sunset”- turning off our devises for a minimum of one hour prior to bedtime. In addition, we can install or enable software on our computers, phones, and tablets that gradually de-saturates blue LED light as evening progresses.
Matthew believes these practices are especially important for our children. “Devices are a wonderful piece of technology. They enrich the lives and education of our youth. But such technology is also enriching their eyes and brains with powerful blue light and artificial stimulation that has a damaging effect on sleep—the sleep that young, developing brains so desperately need in order to flourish.”
Reflection: Does my evening routine typically involve screen time immediately prior to going to sleep?
Action: Consider implementing a “digital” sunset a minimum of one hour before bedtime.