This article is from the Alternative Medicine Therapies guide.
Light therapy is the use of natural or artificial light to treat various ailments, but primarily depressive and sleep disorders. It may be administered by a physician, physical therapist, psychiatrist, or psychologist--or done on one's own with proper instruction from a trained professional. While exposure to the full-spectrum wavelength of natural sunlight is considered the best form of light therapy, it is not always possible for many people to get outdoors. Therefore, light therapists often recommend treatment with simulated sunlight from light boxes.
The form of light therapy most commonly used today is known as bright-light therapy. It requires that you sit near a special light box fitted with high-intensity light bulbs, which may provide either full-spectrum or white light. This type of light therapy has been proven to be particularly useful in treating seasonal affective disorder (SAD), also known as the "winter blues," a form of depression that occurs as the amount of daylight wanes with the change of seasons. It has also been shown to be effective for some sleep disorders.
For SAD, practitioners usually recommend sitting for 15 to 20 minutes in front of a light box with 10,000 lux capacity (a lux is the international unit of illumination, one lumen per square meter). This light is about 15 times brighter than normal home or office lighting. You can also receive light therapy by installing full-spectrum bulbs in place of incandescent or fluorescent room lighting. This method is less effective for depressive disorders, however, because they tend to respond better to intense rather than dissipated lighting.
Two other types of light therapy are: