A team of American scientists from the cities of Champaign, Boston, Millitas and Syracuse claims that people who work in offices with more daylight access sleep longer at night and show higher intelligence than office workers with poor natural light.
Sunlight activates a pigment in the retina — melanopsin, which is involved in the regulation of the pineal gland in the brain — the pineal gland. And the latter produces melatonin, a hormone that regulates human circadian rhythms. It affects the quality of sleep, the time of falling asleep and waking up. There is a parameter that links the amount of daylight and the melanopsin response — melanopic lux (EML): the more light (EML units), the less melatonin.
In the study, 30 adult office workers worked in two different offices for one week. Both offices had exactly the same layout, furnishings and orientation to the cardinal points, but in one case it had a window with electrochromic glass, which changes its optical properties depending on the level of illumination, and in the other the window was covered with blinds, hiding most of the light flux . Accordingly, the lighting in the room with electrochromic glass corresponded to 40.6 EML, and in the room with blinds — 316 EML.
It turned out that the subjects who worked in a room with electrochromic glass and received a lot of daylight slept 37 minutes longer and were 42% better on tests of cognitive function, which tested their ability to make meaningful decisions for work. When the employees participating in the experiment changed places, their indicators also changed. These changes were visible even after one day of work in an office with optimized daylight access or in an office with blinds. But a particularly pronounced difference was observed after a few days.
The researchers highlight the importance of designing offices for daylight workspaces. In their opinion, a sufficient amount of daylight will benefit both office workers and their management.