A recent case-controlled pilot study of office workers published in the Journal of Clinical Sleep Medicine found that the amount of daylight exposure workers received had an impact on workers' sleep quality, activity patterns, and quality of life.
The investigation reported that workers in offices without windows reported limited ability to meet the demands of their jobs due to physical problems, and poorer overall sleep quality. Meanwhile employees in windowed offices who were exposed to more natural light during the work week were more productive and had longer and less disturbed sleep durations.
The study's findings suggest that a lack of exposure to sunlight during work hours can have far-reaching effects on workers. Quality of sleep and insufficient sleep have already been associated with high levels of cortisol (a steroid hormone produced in response to stress), impaired glucose metabolism, increases in appetite, higher body mass indexes, increased fatigue, and deterioration in performance, alertness and concentration. The myriad of health affects and concerns emphasizes the importance of occupational health awareness.
Prior to this study little was known about how architectural features such as windows impacted light exposure and subsequent physical and mental factors. However, there are additional concerns about UV and heat damage from exposure to sunlight through windows. Responding to this, Darrell Smith, executive director of the International Window Film Association, stated, "Letting in abundant daylight into offices is very much desired, but may present a real problem for those who don't want to have harmful UV rays, glare and hotspots negatively impacting their workers' comfort and health. Despite the myths that window film makes indoor spaces dark, window films can let in ample natural sunlight without the downside risks […]."
Michigan Glass Coatings offers a number of solar window film options that allow visible light through windows while blocking any harmful effects, such as UV rays and excessive heat.