by Amol Rao

The IMS Magazine recently conducted a Graduate Student Sleep Survey as part of a feature on sleep. The results, which can be seen in infographic format in the Summer 2016 issue, are quite concerning. Approximately 40% of respondents were unsatisfied or very unsatisfied with the quality of their sleep. A similar percentage were unhappy with the amount of time they sleep. If the survey respondents are any indication, there could be 6,800 grad students at U of T who are unhappy with their sleep.

Of those who were unsatisfied with their sleep quality, only 5% have consulted a sleep specialist and about 20% have tried OTC sleep medication–numbers that are similar for those satisfied with their sleep. This suggests that unhappy sleepers don’t generally seek treatment. A possible explanation is that poor sleep is considered normal or unavoidable due to external requirements. Most commonly mentioned reasons for poor sleep are: stress, work, schedule, and lack of exercise.

Poor sleep can have significant consequences for an individual’s wellbeing. From reduced cognitive function, memory and recall to altered mood and behaviour; over time chronic sleep problems have been linked with increased risk of obesity, stroke, hypertension, and a weakened immune system.[i] Those who experience poor quality sleep are encouraged to seek out and employ strategies and tactics to improve their sleep or consult a specialist.

Artificial Light at Night Time: A Potential Contributor to Sleep Problems

Most respondents expressed the wish to go to bed earlier–however one commonly cited problem was maintaining a regular sleep schedule while balancing a heavy work load.  For most students, this means completing work on a computer in the evening hours.

For a long time, it was thought that night time light was inconsequential to our sleep. However, over the past 20 years many studies have demonstrated that exposure to light in the evening hours disrupts circadian rhythms by suppressing the production of melatonin.[ii] This in turn makes it more difficult to fall asleep and wake on a regular schedule. The disruption is intensity and wavelength dependent, with high energy blue light being the most disruptive.[ii] In addition, light emitting electronic devices have become almost ubiquitous in the last ten years. At a 2012 Annual Meeting, the American Medical Association (AMA) voted to adopt a position statement recognizing that ‘exposure to excessive light at night, including use of various electronic media can disrupt sleep or exacerbate sleep disorders…’[iii]

So what is a hard working grad student to do? Ideally, lights should be dimmed and use of electronic devices minimized in the hours preceding bedtime. Since this isn’t possible for most, the use of free software such as or Apple’s Nightshift which reduce light related disruption should be seriously considered. Alternatively, several studies have shown that selectively filtering the most harmful element of lighting, i.e. blue light in the evening hours, can help improve sleep.[iv][v] Orange light bulbs and blue light filtering eyewear are both commercially available. Lastly, given the increasing attention being paid to sleep from tech startups to lighting companies there is hope that restful sleep is just around the corner, until then it’s off to Tim Hortons.

[i] Driver H, Gottschalk R, Hussain M, et al. Insomnia in Adults and Children. The Youthdale Series. Joli Joco Publications Inc.; 2012

[ii] Reiter RJ, Tan DX, Korkmaz A, et al. Light at night, chronodisruption, melatonin suppression, and cancer risk : a review. Crit Rev Oncog. 2007 Dec; 13(4):303-28.

[iii] American Medical Association (AMA). Report 4 of The Council on Science and Public Health (A-12) on Light Pollution : Adverse Health Effects of Nighttime Lighting; 2012

[iv] Pauley M. Lighting for the human circadian clock : recent research indicates that lighting has become a public health issue. Med hypotheses 2004; 63(4): 588-96

[v] Burkhart K, Phelps JR. Amber lenses to block blue light and improve sleep: a randomized trial. Chronobiol Int. 2009 Dec; 26 (8): 1602-12

Amol Rao is the Operations Manager at Somnitude Inc, which developed the Blue Block Glasses.