We’ve all experienced the impact of poor sleep on our productivity and effectiveness at work. Over the past year I’ve noticed the topic of sleep – particularly the need to attain more of it, has become a major concern for many of us. I’ve been party to countless conversations, where people have fretted about their inability to achieve more than four hours sleep each night. This apparent trend was confirmed by Charles Czeisler, the Chief of the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital, who stated that 69 per cent of individuals are reporting insufficient sleep.

This modern-day ‘sleep crisis’ got me thinking about the root causes which may be driving our collective inability to ‘switch off’. Czeisler and his team have stressed that, “Sleep variability is one of the most important factors in determining how well someone sleeps.” In other words, it’s better to go to bed at a consistent time every night. However, according to Maria Konnikova, who recently wrote an article titled “ Why Can’t We Fall Asleep ?” for the The New Yorker, there remains a greater environmental cause which we need to be aware of  and that’s ‘blue light’.

The human eye is an amazing example of evolution. Within the human eye we have melanopsin receptors which only respond to changes in light and dark. These receptors are connected directly to the part of our brain that regulates our body clocks (a.k.a. circadian rhythms), thereby preparing the body for either wakefulness or sleep. Melanopsin receptors are so effective they even work for many blind people, maintaining their circadian rhythms.

Our environment has certainly changed over the past few years. Today, we are surrounded by computers, televisions, phones, and e-readers. These devices emit shortwave, ‘blue light’ spectrum light which our circadian systems, via the melanopsin receptors, interpret as daylight. The result? They delay melatonin release (a hormone which encourages sleep) for up to 1.5 hours. Critically, a recent study found these profound effects do not require prolonged exposure to ‘blue light’. A single exposure of less than 12 minutes can cause significant sleep disruption.

So, if we’re serious about catching zeds, we need to reconsider answering those last few emails before bed. It’s time to shut down earlier, so we can enjoy more shut-eye.