Considerable research reveals the consistent need humans have for natural light; for health, for productivity, the ‘feel good’ factor, combating SAD and much more.

MA hospital

The intensive care units at Massachusetts General have direct access to natural light, facing out to a central bamboo garden.

Research suggests exposure to daylight in the built environment creates significant health and performance benefits.

This past year, researchers at the Swiss Federal Institute of Technology found that employees working in environments with natural light recorded higher levels of energy than those in artificially-lit workplaces.

Exposure to daylight at the right time of day also suppresses our melatonin, leading to more restful sleep in the evening. From treatment of depression to alleviating workplace stress, daylight in particular is a convenient means to positively impact human health. Taken from “The Link Between Natural Light and Health – CJ Brockway, LC, IESNA, A. IALD

Christopher Bergland is a world-class endurance athlete, coach and author – “We all know the discombobulated feeling of being stuck in a windowless room under fluorescent lights during daylight hours.” Men sleep at desk

Researchers at the Interdepartmental Neuroscience program at Northwestern University in Chicago, found that the detrimental impact of working in a windowless environment is a universal phenomenon. A new study titled, “Impact of Workplace Daylight Exposure on Sleep, Physical Activity, and Quality of Life,” concludes that there is a strong relationship between workplace daylight exposure and office workers’ sleep, activity and quality of life. The research was published recently in an online supplement of the journal SLEEP.

The study group comprised 49 day-shift office workers — 27 in windowless workplaces and 22 in workplaces with windows.

Compared to workers in offices without windows, those 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. Workers without windows reported lower scores than their counterparts on quality of life measures related to physical problems and vitality. They also had poorer outcomes in measures of overall sleep quality, sleep efficiency, sleep disturbances and daytime dysfunction.

“The extent to which daylight exposure impacts office workers is remarkable,” said study co-author Ivy Cheung, a Neuroscience doctoral candidate at Northwestern University

Daylight and Circadian Rhythms

Circadian rhythms are biological, mental and behavioural changes that follow a 24-hour cycle and respond to light and darkness within an organism’s environment. Circadian rhythms are found in almost every living thing, including: human beings, animals, plants and even tiny microbes.

Circadian rhythms are produced by natural factors within the body, but they are mostly affected by signals from the environment. Light is the main cue influencing circadian rhythms. Exposure to light turns the genes that control an organism’s internal clocks “on” and “off.” Circadian rhythms dictate: sleep-wake cycles, hormone release, body temperature and other important bodily functions.

Disruptions of circadian rhythms is directly linked to sleep disorders. Abnormal circadian rhythms have also been associated with obesity, diabetes, depressionbipolar disorder and seasonal affective disorder(SAD).

Circadian Rhymn

The “master clock” that controls circadian rhythms consists of a group of nerve cells in the brain called the suprachiasmatic nucleus, or SCN. The SCN contains about 20,000 nerve cells and is located in the hypothalamus. Destruction of the SCN results in the complete absence of a regular sleep–wake cycle.

The SCN receives information about illumination and the quality of light through the retina. The retina contains “classical” photoreceptors (“rods” and “cones”), which are used for vision. The retina also contains specialized cells which are photosensitive and project directly to the SCN where they entrain your master circadian clock to synchronize biological rhythms.

The SCN takes the information on the length of the day and night from the retina, interprets it, and passes it on to the pineal gland. In response to signals from the SCN, the pineal gland secretes the hormone melatonin. The secretion of melatonin peaks at night and ebbs during the day which drives our sleep-wake cycle.

The presence of melatonin also provides information about the length of night. Several studies have indicated that pineal melatonin feeds back on SCN rhythmicity to modulate circadian patterns of activity and other processes. However, the nature and significance of this feedback loop are unknown.

Sunsquare, UK  says “It sounds crazy, but when it comes to implementing changes for a positive office environment, many have argued for the health benefits from natural light, particularly sunshine. Sunshine is very important for well-being because of the UV rays it provides. These help the human body to produce vitamin D, dubbed ‘the sunshine vitamin’ by health experts. Vitamin D has been hailed as an effective treatment for allergies, back pain, tension headaches and namely, depression.

In 2008, a study of 1,000 city workers by the Federation for Small Businesses found that 22% of workers got less than 20 minutes of sunshine a day. As a result, two-thirds of participants suffered with depression and four out of five blamed their lack of motivation on their sunless working environments.”

 “People are just happier when they have the sun shining on them.” By Scott Ryan, home and office interior design expert

Natural light looks nice. Not only is it practical and economical to rely on natural lighting, it is also pretty. You can’t go wrong. The next time you renovate or remodel, keep natural light in mind. By Josh Peterson, Planet Green