What Studying the Blind Teaches Sleep Scientists

In our round-the-clock society filled with stress and responsibility, adequate sleep has become an increasingly rare and valuable commodity. The demands of work, family responsibilities, overstimulation from caffeine, alcohol and the ever-present blue light glow of our tablets and cell phones make getting the rest we need even more difficult, and may be damaging our body’s ability to recognize when exactly we are supposed to be awake and when we are supposed to be asleep. This rhythm, known to sleep scientists as the circadian rhythm, is our body’s clock. Back before the industrial revolution, when we largely survived by farming and without electric light, the body clock was largely set by the rising and setting of the sun. But our modern world has wreaked havoc on this evolutionary system, and as a result our ability to get the rest we need has suffered, as has our health. Lack of adequate sleep has been definitively linked to an increased risk of diabetes, obesity, cancer and depression, as well as problems with productivity and safety, so now we need to find a way back to a good night’s sleep.

Much of the research into the role of light in our ability to get to sleep is being done by neuroscientists. It has been well established that light is the dominant factor in the establishment and regulation of the body’s sleep clock; it is also well known by sleep scientists that even though we have a 24-hour day, when allowed to operate independent of light the body’s clock actually runs slightly longer than that. It is our exposure to sunlight and darkness that resets our brains each day and makes us adhere to the 24-hour cycle, making sure that we are alert at the right time, drowsy at the right time, that our body temperature is appropriate for waking hours vs. sleeping hours, etc. But scientists at Brigham and Women’s Hospital in Boston have been trying to determine what happens when the body can’t see light, and what happens to the circadian rhythm in the absence of these cues.

One thing that can happen is that the blind fall victim to a syndrome known as Non-24-Hour Sleep-Wake Disorder. As you might suspect, without the presence of light to guide their body into sync with society’s 24 hour schedule, those who have Non-24 find themselves operating on their own individual body clock. Each day they operate on something closer to a 25-hour cycle, thus putting them out of sync with the work and life cycle that the rest of the world around them follows. This is highly disruptive. They fall asleep an hour later each night and wake an hour later each day.  They end up being profoundly sleepy during the day light hours and unable to sleep during the evening.  Though they fight its impact, they often find that they end up cycling in and out of the schedule that the rest of their social circle and family keep.

There are almost 100,000 people who have been diagnosed with Non-24. They are all completely blind, and all have the problem of being sleepy during the day that they may fall asleep in the middle of a conversation. Their lives are disrupted to an extreme. The best description of the way that they feel is as though they have jet lag all the time.

In an effort to help those who suffer from this condition, sleep scientists are trying to determine whether there is something other than light that can help adjust their circadian rhythm.  One of the most promising studies done to date has been on a synthetic version of the hormone melatonin. Melatonin has long been credited with helping people to get to sleep more easily, and sleep researchers have had some success in readjusting the body clock of the blind who suffer from Non-24 by providing them with a daily treatment of the supplement. However, it is not clear exactly what dosage is most effective and whether the effectiveness is determined by timing, dosages and the strength of the supplement or by the individual. Since testing melatonin, the scientists are now turning to research into a drug that works in a similar way.

While the immediate goal of this research is to offer a solution for those who are suffering from Non-24, the benefits of the studies can extend far beyond this particular group into the general population.  The more that sleep scientists understand about the impact of light on the body and what other interventions can take the place of light, the more they will be able to help those whose circadian rhythms are thrown off by other problems, including a number of different sleep disorders and the previously mentioned issues of caffeine, stress and intrusive technology.

It can also help those who work on night shift, those who travel across time zones and suffer from crippling jet lag problems, and those who suffer from disorders such as delayed sleep phase syndrome.  Additionally, there is a newly developing field of medicine known as chronomedicine that is dedicated to understanding how timing can impact the effectiveness of different medications, and it is thought that having a better understanding of the circadian cycle and how to control it may be beneficial to this new area of study.

The more that medical science understands about the role of the sun’s light, as well as how it can be replaced, the better it will be able to help those who suffer from a number of issues that can play a part in our overall health and wellness.  With lack of sleep having been proven to be a major factor in issues of both safety and productivity, it is essential that we learn everything we can to combat the growing problem of sleep deprivation.