Those who sit near a window were also found to have less
broken sleep and a better quality of life than employees deprived of daylight.
Researchers say better designed workplaces could boost the physical and mental
health of workers.
However, the result of all those sleepless nights is more
than just bad moods and a lack of focus and regular poor sleep raises the risk
of serious medical conditions like obesity, heart and diabetes - and can even
shorten life expectancy.
Researchers from the University of Illinois, Northwestern
in Chicago and the
Hwa-Hsia Institute of Technology
in Taiwan, teamed up to examine the
role of workplace windows in helping sleep.
They recruited 49 office employees, just over half of whom
spent the day in mostly windowless offices, while the rest experienced frequent
exposure to daylight through windows.
Each one was interviewed on sleeping patterns, physical
activity and general lifestyle. Some of the volunteers also wore hi-tech watches
round-the-clock for 14 days to measure their light exposure, levels of physical
activity and sleep/wake times.
The results showed those with the most work-time light
exposure enjoyed an average of 46 minutes more per night than their
light-deprived colleagues. They also scored better on a sleep quality scale and
reported fewer night-time disturbances.
Researchers said: "Architectural design of office
environments should place more weight on adequate daylight exposure for workers
in order to promote health and well-being."
"Body needs exposure to daylight to keep its sleeping
patterns on track. Light is essentially the thing that tells our bodies to be
awake and dark tells them to go to sleep. The problem with office lighting is
that it is not made up of 'blue' light, which is the wavelength of light you
get from the sun and which controls your body clock.
'So you could have a very well lit office but it does not
have the same effect because it's artificial and does not contain blue light,"
explained Dr Neil Stanley.
The study was published in the Journal of Clinical Sleep