Since time immemorial nature's light-dark cycle, the circadian rhythm, has provided us with a biological clock that, through the secretion of light-sensitive hormones, has made us more alert during the day and tired at night, controlled our body temperature, our metabolism and our activity preparedness, etc.
Artificial lighting affects the hormonal balance that ensures we have an efficient 24-hour rhythm by elevating the level of cortisol in the blood. Elevated levels of cortisol at the wrong time of day can cause problems such as difficulty in resting and sleeping soundly: this REM, deep sleep is the reparative, regenerative phase of the 24-hour cycle. Insomnia has severe adverse consequences on our bodily functions making it more difficult to maintain our health. One sign of this is that we tend to feel more tired when we wake up than when we went to bed.
If you feel as though you have got into a downward spiral of fatigue, you can find out more about the role played by natural daylight and artificial light in your life. You can take advantage of natural daylight, artificial light and darkness to improve your health and well-being.
The Light Room has been specially designed and created to help those students who feel tired and exhausted during the dark period of the year. In the Light Room exposure to artificial bright light is intended to help you feel more alive and energetic in the morning.
A Light Room with artificial light is inevitably a short-term solution. It is only by being exposed to direct natural daylight that the body will be able to have and maintain the right levels of cortisol and melatonin, i.e. the sleep/wake hormones in the blood at the right time during the 24-hour period, which can be difficult in our part of the world during the wintertime.
The only real long-term solution to seasonal fatigue is to spend as much time outdoors as possible.
Several articles have been published on the light-sensitive human processes. Some useful search words for those who would like to learn more about this area of research are Brainard, the third receptor, Fontenoyt, Hollwich and Rickard Kuller, to name but a few.