SAD light boxes are easy to use, but the intensity (lux) of the light, the duration of each daily treatment, the ideal time of day for treatment, and the distance you sit from the light has to be individualized. People who have ever experienced a major depressive episode or a manic or hypomanic episode should consult with a psychiatrist or other medical doctor before using a SAD light box. People with diseases of the retina or other eye disease should seek the advice of an opthamologist, who should monitor the patient during the course of treatment.

Determine Your Best Time of Day for SAD Light Treatment

Go online to the not-for-profit Center for Environmental Therapeutics (see link in the resources section.) Enter the site for consumers and patients and click on the "self-assessment" tab.

Click on the the link for "Your circadian rhythm type Auto(MEQ.)"

Answer the 19 questions in this free, anonymous test. "MEQ" stands for Morningness-Eveningness Questionnaire. Based on your answers to the MEQ, you will receive a recommendation about the best time of day to start your SAD light therapy.

The test was developed by SAD light treatment expert Michael Terman and others. Terman is the Director of the Center for Light Treatment and Biological Rhythms at Columbia University New York-Presbyterian Hospital.

Set up Your SAD Light and Begin Treatment

Place the SAD light at a table with a comfortable chair and turn on the light. The treatment usually begins with 30 minutes of exposure to 10,000 lux in the morning.

At the designated treatment time, sit 12 inches from the screen and focus on the work surface. You can read, write, work on a laptop computer, eat breakfast, or do another task that draws your eyes to the work surface while seated in front of the light.

Make sure your head and body are oriented towards the light, but do not look directly at the light.

Monitor for Side Effects and Improvement

Improvement should be seen within the first week of regular treatment. If no improvement occurs, consult a professional.

Notice if you experience minor side effects, such as fidgetiness, eye strain or irritation, restlessness, headache or mild nausea. These usually subside within a few days. If not, you may wish to decrease the lux.

If eye irritation does not resolve, you can try sitting farther from the light, sitting for less than 30 minutes, using a humidifier or artificial tears eyedrops.

If you experience insomnia, a "speedy" or "too high" feeling, restlessness and irritability, this could be a manic episode and can indicate the presence of bipolar disorder. Seek the care of a psychiatrist immediately. Sometimes light therapy can be continued with the use of a mood-stabilizing drug.

Continue treatment daily until the time of year your mood and symptoms usually resolve themselves naturally, without treatment. For most people this is in spring.


The standard dose of treatment is 10,000 lux for 30 minutes at 12 inches from the light in the morning but each person is different. If no benefit is achieved, consult an expert before giving up.


If you have ever experienced a major depressive episode or a manic episode, do not treat yourself with SAD lights. Consult a psychiatrist or other medical doctor to supervise your treatment.

If you have diseases of the retina or other eye problems, consult your ophthalmologist before and during the use of light treatment.