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Light therapy

What is it?

Light therapy is the use of sunlight and other forms of light to help restore health or treat disease. Natural sunlight and artificial light have been used for over 100 years to treat certain physical and emotional diseases. Recently, Western medicine has learned the importance that light plays in regulating the body's biological clock. Sleep patterns, hormone levels, body temperature, and other body functions are strongly affected by light.

The oldest form of light therapy is natural sunlight. Other forms of light therapy currently used include full spectrum, bright light, ultraviolet (UV) light, syntonic optometry, cold laser, and colored light.

Any situation that disrupts or limits our exposure to light can affect these important reactions. Doctors have recently discovered a type of depression that occurs as a result of decreased sunlight. During the winter months, there is a reduced amount of sunlight. Many people are affected by reduced sunlight and have a type of depression that is known as "seasonal affective disorder," or SAD.

SAD is also known as the winter blues. Symptoms of SAD include depression, fatigue, excessive sleeping and eating, feeling withdrawn, and a decreased sex drive. Several studies in the 1980's suggested that reduced sunlight may cause this type of depression and that it might be corrected using full spectrum or bright white light.

Full spectrum lights emit UV light that may harm the eyes so bright white light is now used for SAD treatment. The patient sits in front of the light box, with the light pointed at the face, from 30 minutes to two hours a day. Reading or other activities may be done while having light therapy. Most studies show improvement within one week of beginning therapy.

In 1903, Dr. Niels Finsen won a Nobel prize for his work with light therapy for the treatment of skin disease. Since that time, light treatment has been a standard of practice in Western medicine. Doctors treating patients with psoriasis have had up to 90% success using light therapy.

Psoriasis and SAD are two conditions that have been widely studied. Both show that light therapy may be beneficial. Light therapy may also be used to treat bulimia, anorexia, sleep disorders, menstrual problems, or hypertension. Depression, migraine headaches, sugar cravings, hyperactivity, and poor immune function may also be treated with light therapy.

For more information:


1. Burton Goldberg Group: Alternative Medicine: The Definitive Guide. Future Medicine Publishing, Puyallup, WA; 1994.

2. Cassileth BR: The Alternative Medicine Handbook, 1st ed. WW Norton & Company, NY, NY; 1998:16-21.

3. Sifton DW: The PDR Family Guide to Natural Medicines and Healing Therapies. Three Rivers Press, NY, NY; 1999.

4. Woodham A & Peters D: Encyclopedia of Healing Therapies, 1st ed. Dorling Kindersley, NY, NY; 1997:90-94.

Last Updated: 9/15/2016

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