The windows in your office may open gateways to good health as researchers have found that daylight in office improves worker's sleep, physical activity and quality of life.

Employees with windows in the workplace received 173 percent more white light exposure during work hours and slept an average of 46 minutes more per night than employees who did not have the natural light exposure in the workplace, the findings showed.

"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," said Phyllis Zee, a neurologist and sleep specialist at Northwestern University in the US.

"The study results confirm that light during the natural daylight hours has powerful effects on health," Zee added.

There was also a trend for workers in offices with windows to have more physical activity than those without windows.

Workers without windows reported poorer scores than their counterparts on quality of life measures related to physical problems and vitality.

"Light is the most important synchronising agent for the brain and body," said Ivy Cheung, a Ph.D. candidate in neuroscience in Zee's lab at Northwestern.

A simple design solution to augment daylight penetration in office buildings would be set to make sure the workstations are within 20 to 25 feet of the peripheral walls containing the windows, said co-author Mohamed Boubekri from University of Illinois at Urbana-Champaign.

The study involved 49 day-shift office workers; 27 in windowless workplaces and 22 in workplaces with windows.

The study appeared in the Journal of Clinical Sleep Medicine.