Zlatko Glusica was the captain of an Air India Express plane carrying 166 passengers from Dubai to Mangalore, a bustling port city on India's southern coast. As his Boeing 737 approached the city, Mr. Glusica woke up from a nap in the cockpit and took over the controls. His co-pilot warned him repeatedly that he was coming in at the wrong angle and that he should pull up and try again. The last sound on the cockpit recorder was the co-pilot screaming that they didn't have any runway left. The plane overshot the landing and burst into flames. Only eight people survived. An investigation found that the captain was suffering from "sleep inertia."
The accident was a fatal reminder of the power of something prosaic that most of us typically don't give much thought: sleep. Yet it's a lesson that is habitually forgotten. Since that 2010 Air India flight, sleepy pilots have been at the center of several near-accidents, including two this year. In April, 16 passengers of an Air Canada flight were injured after the plane's pilot went into a sudden dive after he mistook the planet Venus for an oncoming plane. And in July, a Texas judge found that a JetBlue pilot's bizarre ranting in the cabin was a psychotic breakdown that may have been caused by a lack of sleep.
It isn't just the airline industry. Some 20% of automobile accidents come as the result of drowsy drivers, according to the Centers for Disease Control and Prevention. U.S. military researchers, meanwhile, have concluded that sleeplessness is one of the leading causes of friendly fire.
Sleep wasn't something we were supposed to worry about in the early years of the 21st century. Technology was making the world smaller by the day; the global economy blurred the lines between one day and the next, and things like time and place were supposed to be growing ever less important in the always-on workplace. Most of us never gave sleep much thought—considering it nothing more than an elegant on-off switch, like the ones on our smartphones, that the body flips when it needs to take a break from its overscheduled life. Sure, we'd like to get a bit more of it. But, beyond that, sleep likely hovers somewhere near flossing in most of our lives: something we are supposed to do more—but don't.
Americans, however, are starting to wake up about sleep. Endless ads for dubious energy drinks and an equal number of much slicker ads for prescription sleep aids reveal a culture in 2012 that is wired and tired. Lack of sleep, it seems, has become one of the signature ailments of our modern age.
Nearly a third of working adults in America—roughly 41 million people—get less than six hours of sleep a night, according to a recent CDC report. That number of sleep-deprived people is up about 25% from 1990. About 27% of workers in the financial and insurance industries are sleep-deprived, according to the CDC, while nearly 42% of workers in the mining industry share the same complaint. A 2011 study published in the journal Sleep found that insomnia costs $2,280 per worker in lost productivity, adding up to $63.2 billion nationwide.
This skyrocketing sleeplessness has given rise to a large and growing industry: Americans now spend tens of billions of dollars on prescriptions, at sleep labs, on mattresses and for medical devices in our quest for some simple shuteye, according to Marketdata Enterprises, a market research firm based in Tampa, Fla. "Fatigue management consultants," meanwhile, now work with more than half of the current Fortune 500 companies, law-enforcement groups and even Super Bowl-winning teams on ways to maintain a consistently high-performing workforce and prevent accidents.
So why is sleep, which seems so simple, becoming so problematic? Much of the problem can be traced to the revolutionary device that's probably hanging above your head right now: the light bulb. Before this electrically illuminated age, our ancestors slept in two distinct chunks each night. The so-called first sleep took place not long after the sun went down and lasted until a little after midnight. A person would then wake up for an hour or so before heading back to the so-called second sleep.
It was a fact of life that was once as common as breakfast—and one which might have remained forgotten had it not been for the research of a Virginia Tech history professor named A. Roger Ekirch, who spent nearly 20 years in the 1980s and '90s investigating the history of the night. As Prof. Ekirch leafed through documents ranging from property records to primers on how to spot a ghost, he kept noticing strange references to sleep. In "The Canterbury Tales," for instance, one of the characters in "The Squire's Tale" wakes up in the early morning following her "first sleep" and then goes back to bed. A 15th-century medical book, meanwhile, advised readers to spend their "first sleep" on the right side and after that to lie on their left. A cleric in England wrote that the time between the first and second sleep was the best time for serious study.
The time between the two bouts of sleep was a natural and expected part of the night, and depending on your needs, was spent praying, reading, contemplating your dreams or having sex. The last one was perhaps the most popular. A noted 16th-century French physician named Laurent Joubert concluded that plowmen, artisans and others who worked with their hands were able to conceive more children because they waited until after their first sleep, when their energy was replenished, to make love.
Studies show that this type of sleep is so ingrained in our nature that it will reappear if given a chance. Experimental subjects sequestered from artificial lights have tended to ease into this rhythm. What's more, cultures without artificial light still sleep this way. In the 1960s, anthropologists studying the Tiv culture in central Nigeria found that group members not only practiced segmented sleep, but also used roughly the same terms to describe it.
That natural cycle was forever changed by Thomas Edison (whose contributions to our sleepless nights also extend to his work on the phonograph and the motion picture). Soon, sunset no longer meant the end of your social life, but the beginning of it. Night became the time when all the good stuff happens. And, for businesses, it meant that darkness no longer got in the way of production. Factories soon began running all night long. By the 1920s, the idea of a first and second sleep had entirely disappeared from our daily rhythms, completing a process that had begun 200 years earlier with the introduction of the first gas lamps and the surge in the number of coffee houses in Northern Europe. Now we have so much artificial light that after a 1994 earthquake knocked out power, some concerned residents of Los Angeles called the police to report a "giant, silvery cloud" in the sky above them. It was the Milky Way. They had never seen it before.
None of us wants to go back to a time before electric lights, of course. Yet our attempts at blending our natural sleep rhythms with the modern world look to be failing—especially as the electric light has migrated from the ceiling to the palms of our hands, where smartphones and other devices now rarely leave our side.
The consequences of this change in lifestyle are far more dire than a simple loss of connection to the natural world. Researchers are increasingly finding that lack of sleep is terrible for our health. Sleeplessness has been linked to increased rates of heart disease, obesity, stroke and even certain cancers. The exact reasons for these effects are still largely unknown, but give support to the theory that sleep is the time when our bodies naturally repair themselves on a cellular level.
Recently, researchers have also found how important these overlooked hours are to our mental performance. Sleep, or the lack of it, is now thought to be a complex process that underpins everything from our ability to learn a new skill to how likely we are to find a novel solution to a problem. It is also considered a vital part of happiness and one of the best forms of preventative medicine.
Many of us try to mitigate our lack of sleep with coffee and sleeping pills, but it just doesn't work. Caffeine may work in the short-term, but it isn't a long-term solution for the average person because the body begins to build up a tolerance to it. Soon, higher and higher doses are required to get the same effect. Strong doses of caffeine tend to make the body jittery and, once the caffeine wears off, lead to crashing in exhaustion.
And no amount of caffeine can alleviate the need for sleep. When that time comes, many adults turn to sleeping pills for help. About 60 million prescriptions for sleeping pills were filled in the U.S. last year, according to IMS Health, a data and analytics firm in Parsippany, N.J. That number is up from 48 million in 2006. Yet a number of studies have shown that drugs like Ambien and Lunesta offer no significant improvements in the quality of users' sleep.
And they only give you the tiniest bit more in the quantity department. In one meta-analysis of sleeping pill studies sponsored by the National Institutes of Health and published in 2007, patients taking popular prescription sleeping pills fell asleep just 13 minutes faster than those given a sugar pill. They slept for a grand total of 11 minutes longer. People seem to overestimate the effectiveness of sleeping pills, partly because of the placebo effect, and partly because some of these pills cause short-term memory loss that leaves people believing they got better sleep than they actually did—they just don't remember all their tossing and turning.
So why don't we put more effort into dealing with our sleep problems? While we'll spend thousands on lavish vacations to unwind, grind away hours exercising and pay exorbitant amounts for organic food, sleep remains ingrained in our cultural ethos as something that can be put off, dosed or ignored. We can't look at sleep as an investment in our health because—after all—it's just sleep. It is hard to feel like you're taking an active step to improve your life with your head on a pillow.
Nonetheless, there are steps we can take to adapt the way we approach sleep to be more effective for modern life. In a new branch of sleep medicine, scientists have identified how to get a good night's sleep naturally. Most of the suggestions come down to changing your behavior. One thing you can do is go to bed at the same time every night. Also, studies have shown that people should avoid the bluish light from computer screens, TVs and smartphones—which our brains interpret as sunlight—for at least an hour before bed. And, by doing yoga or other relaxation techniques that put the mind at ease, subjects in studies have dramatically improved both their sleep quality and quantity.
Poor sleep habits can also be a data problem. With nothing more than hazy memories of the night to go on, most of us have only rough estimates of when, exactly, we fell asleep—and whether we spent the night tossing and turning. New consumer devices, like headbands that measure brain waves during the night and pedometer-like devices that measure movement, can give the home user data rivaling what they might get in a sleep lab. Such data can allow people to pinpoint the real effects of each day's choices on their night's sleep.
Such tracking and behavioral adjustment isn't that far removed from the work that fatigue-management consultants do. Their work often consists of combing accident reports and comparing them with work schedules to find out how long employees on duty had been awake. By charting the outcomes, fatigue-management consultants are often able to prove that a greater respect for sleep can lead to better results at the office, whether that office is a multinational corporation or a local fire department.
The secret to a good night's sleep may very well be acknowledging that it takes work. And that the work is worth it. Health, mental sharpness, sex, relationships, creativity, memories—all of these things that make us who we are depend on the hours we spend each night with our eyes closed.
As Heraclitus wrote 2,500 years ago: "Even a soul submerged in sleep is hard at work and helps make something of the world."