The research study indicates that artificial light disrupts our natural sleep cycles in an unhealthy way and exposure to such light keeps us awake longer and makes our sleep less restorative.
Previous studies have demonstrated that poor sleep is associated with poorer cognitive performance and produces negative effects such as mood swings, daytime fatigue, poorer performance at work, at school or in traffic, and in the worst cases leads to substance abuse, diabetes and obesity.
Dr. Wright and his research colleagues had groups of people live in tents in the wilderness for short and long periods of time, and then compared the subjects' sleep cycles with their everyday sleep cycles.
The study found that whether the subjects stayed outdoors for a weekend or a whole week, their bodies quickly adapted according to the biological night, which is close to the sun's setting and rising, giving the subjects longer and better sleep, according to the study.
Dr. Wright's study also showed that melatonin, which makes us sleepy, increased when the sun went down but quickly disappeared when the subjects woke up, unlike when we sleep in the artificial light environment of the home where our melatonin levels are relatively high long after we wake up. This explains why we are often a bit grumpy and irritable in the morning.
Read the full study here.