By Mayo Clinic Staff
Light therapy is a way to treat seasonal affective disorder (SAD) by exposure to artificial light. Seasonal affective disorder is a type of depression that occurs at a certain time each year, usually in the fall or winter.
During light therapy, you sit or work near a device called a light therapy box. The box gives off bright light that mimics natural outdoor light.
Light therapy is thought to affect brain chemicals linked to mood, easing SAD symptoms. Using a light therapy box may also help with other types of depression, sleep disorders and other conditions. Light therapy is also known as bright light therapy or phototherapy.
You may want to try light therapy for a number of reasons:
In addition to seasonal affective disorder, light therapy is used as a treatment for other conditions, including:
Light therapy is also used to treat skin conditions such as psoriasis. However, this is different from the type of light therapy used for SAD and the other conditions above. Light therapy for skin disorders uses a lamp that emits ultraviolet (UV) light. This type of light is filtered out in light therapy boxes because it can damage the eyes and skin.
Although it's possible to do light therapy on your own, it's best to ask your doctor or mental health provider if it's a good option for you. Also ask whether you need to take any special precautions. This guidance can help you get the most benefit and minimize possible side effects.
Internet retailers, drugstores and even some hardware stores offer a variety of light therapy boxes. Or your doctor may recommend a particular light therapy box. Health insurance companies rarely cover the cost.
Talk with your doctor about the best light therapy box for you, and familiarize yourself with the variety of features and options to help ensure that you buy a high-quality product that's safe and effective.
Generally, most people with seasonal affective disorder begin treatment with light therapy in the early fall, when it typically becomes cloudy in many regions of the country. Treatment usually continues until spring, when outdoor light alone is sufficient to sustain a good mood and higher levels of energy.
If you typically have fall and winter depression, you may notice symptoms during prolonged periods of cloudy or rainy weather during other seasons. You and your doctor can adjust your light treatment based on the timing and duration of your symptoms.
If you want to try light therapy for nonseasonal depression or another condition, talk to your doctor about how light therapy can be most effective.
During light therapy sessions, you sit or work near a light box. To be effective, light from the light box must enter your eyes indirectly. You can't get the same effect merely by exposing your skin to the light. While your eyes must be open, don't look directly at the light box, because the bright light can damage your eyes. Be sure to follow your doctor's recommendations and the manufacturer's directions.
Light therapy is most effective when you have the proper combination of duration, timing and light intensity:
Light therapy requires time and consistency. You can set your light box on a table or desk in your home or office. That way you can read, use a computer, write, watch TV, talk on the phone or eat while having light therapy. But stick to your therapy schedule and don't overdo it.
Some light boxes are even available as visors that you can wear, although their effectiveness isn't proved.
Light therapy probably won't cure seasonal affective disorder, depression or other conditions. But it may ease symptoms, increase your energy levels, and help you feel better about yourself and life.
Light therapy can start to improve symptoms within just a few days. In some cases, though, it can take two or more weeks.
Light therapy isn't effective for everyone. But you can take steps to get the most out of your light therapy and help make it a success.
Taken from: http://www.mayoclinic.org/tests-procedures/light-therapy/basics/definition/prc-20009617