Light directly influences our emotions because it reaches the brain through the eyes, and is transmitted to the hypothalamus. The hypothalamus is connected to almost every other part of the brain, and involved with the regulation of hormones involved in motivation and reward. As a consequence, light has an affect on our basic drives and biological functions.
Bright light also inhibits the secretion of the sleep hormone, melatonin. Low light and darkness stimulates the pineal gland to secrete melatonin, so necessary for a good night's sleep, but counter-productive during the day. Those who suffer from SAD (Seasonal Affective Disorder) where seasonally low levels of light produces a form of depression, quite severe in some people, can find light therapy particularly effective.
The rest of us benefit greatly from exposure to good light levels, too. Twenty minutes walk a day in the sunshine which, even on an overcast day is between 5 and 20 times stronger than normal indoor lighting, is often advocated for improvement of mood and motivation, but what can you do if daily opportunities for adequate exposure to sunshine or bright daylight are limited?
Full spectrum lighting is the closest thing to natural sunlight, and used to treat those with SAD. But its benefits can also be utilised by the rest of us. Working with a full spectrum desk light can improve concentration, especially when long hours of desk work are necessary.
Many office workers have to put up with fluorescent lighting, which also flickers imperceptibly, making it very tiring to the eyes and, as a consequence, to the brain. Installing full spectrum lighting into work environments avoids this, and can improve productivity because of increased levels of wellbeing, motivation, concentration and a happier mood.
Which is why I work with a full spectrum desk light.
Living in the northern hemisphere, over the winter months and long dark days it's particularly beneficial, but provides a good source of light whenever I need it - although I do have to be sure not to use it for a couple of hours prior to bedtime. I need that melatonin as much as anybody, but at night, not when I'm trying to concentrate!
For more information on full spectrum lighting www.lumie.com