Sunlight regulates much of our bodily functions: sleeping patterns, moods, immune system, stress levels and resulting blood pressure.

What happens when there is not enough sunlight entering our eyes? The body becomes tired and lethargic. Growth in children is affected and our immune systems become compromised. It can even affect our mood swings.

For people living in the northern hemisphere, this can be a problem during long winter months when there are shorter daylight hours. Many people, especially women, may experience the "winter blues," a condition stemming from Seasonal Affective Disorder (SAD for short), exhibiting symptoms of lethargy, drowsiness, irritability, food binges, loss of sexual drive, social withdrawal, mood swings, and depression.

The solution? Supplement natural sunlight with artificial emulated sunlight in the form of full spectrum lighting, (FSL). First introduced by fast motion photographer John Ott, full spectrum lighting, in effect, provides most of the benefits of sunlight without its harmful UV effects.

In his book Health & Light, Ott describes the many health benefits of sunlight and FSL, including:

Ott's observations have also been substantiated with other studies in North America: experimental schools with FSL have found symptoms of hyperactivity in ADHD children significantly educed, overall concentration and on-task performance significantly higher, and incidences of dental caries, as well as absences due to various illnesses significantly reduced.

Studies have also found where FSL is used in workplaces, the incidences of stress-related illnesses and illness-induced absences significantly reduced.

My personal experience with full spectrum lighting has also been very positive. Two years studying under the light enabled two students living with me to reduce their prescription lenses for nearsightedness. My qigong/chi kung students and other visitors noted the lights had a calming effect on them. Many of them informed me that unlike regular incandescent light bulbs or cool white fluorescents, these were not only brighter but "more comfortable" on their eyes.

There is ongoing debate whether the effects of FSL are largely psychological, but personally, I have also found them much easier on the eyes and find I'm able to concentrate better.

How does full spectrum lighting treat hypertension? It affects the hypothalamus center in the brain and the photo-sensitive pineal gland that produces the "hibernation hormone" melatonin for sleep. Increased light entering the eyes signals to the brain via optical nerves to decrease melatonin levels, increase oxygen intake and production of serotonin, the hormone responsible for mood elevation, and reduce production of stress hormones such as cortisol.

Full spectrum lighting alone will not cure your hypertension, but, in combination with other qigong/chi kung practices, can definitely help in reducing high blood pressure. Having said that, not all FSL is the same in quality: educate yourself and shop around.

There are two main kinds of full spectrum lighting: one in the form of a light bulb, the other as a fluorescent tube. Appearance aside, I prefer the fluorescent tube, as it has a higher quality of light - 10,000 LUX (candlepower), which also works out cheaper and lasts longer than your average light bulb.

If you are using FSL for reading, position it two feet overhead to shine in a 45 degree downward angle. Ideally, you should have two fluorescent tubes to get enough light intensity to equal that of a midday sun. Do not cover them with anything that will filter the light - your eyes must be directly exposed to the full spectrum in order to benefit from it.

Try it - sunlight and full spectrum lighting for hypertension and a host of other benefits.