Natural daylight streaming in from the windows of your workplace has shown to significantly improve the health of employees. The benefits may sway employers to implement simple design solutions to increase their workforce output and overall well-being. Researchers from researchers at Northwestern Medicine and the University of Illinois at Urbana-Champaign published their illuminating study in the Journal of Clinical Sleep Medicine.

"There is increasing evidence that exposure to light, during the day, particularly in the morning, is beneficial to your health via its effects on mood, alertness, and metabolism," Dr. Phyllis Zee, the study’s lead author and a neurologist and sleep specialist at Northwestern Medicine, said in a press release. "Workers are a group at risk because they are typically indoors often without access to natural or even artificial bright light for the entire day. The study results confirm that light during the natural daylight hours has powerful effects on health."

People need to be exposed to natural light, and researchers wanted to understand what happens to those of us who spend 40 hours a day without any natural light, except if we slip out for a coffee or lunch break. Researchers measured the health-related quality of life, sleep quality, physical activity in relation to the light exposure of 49 employees who work during the day, 27 of whom were in windowless workplaces, while 22 had exposure to windows and natural light. Employees who received 173 percent more light exposure slept an average 46 minutes more with a higher quality of sleep than those who weren’t exposed.

"Light is the most important synchronizing agent for the brain and body," said Ivy Cheung, the study’s co-author and Ph.D. candidate in neuroscience in Zee's lab at Northwestern. "Proper synchronization of your internal biological rhythms with the earth's daily rotation has been shown to be essential for health.”

Each employee was given an actigraphy, which is a wristwatch-like device that monitors the amount of light exposure, activity, and sleep the user undergoes throughout the day and records the results. By just letting some natural light into the office with simple design changes, the employees with be healthier, happier, and ultimately work better.

"Architects need to be aware of the importance of natural light not only in terms of their potential energy savings but also in terms of affecting occupants' health," said the study's co-uthor Mohamed Boubekri, an associate professor of architecture at the University of Illinois at Urbana-Champaign. "Daylight from side windows almost vanishes after 20 to 25 feet from the windows.”

Source: Zee PC, Wang CH, Reid KJ, Cheung IN, and Boubekri M. Impact of Windows and Daylight Exposure on Overall Health and Sleep Quality of Office Workers: A Case-Control Pilot Study. Journal of Clinical Sleep Medicine. 2014.