Light Therapy for Depression
1) The important parameters for light therapy are the brightness of the lightbox and the length of time one sits in front of it each day. Regular bulbs are as effective as “full spectrum bulbs” and cost quite a bit less. The keys to successful light therapy are brightness and length of exposure, not the color temperature of the light.
2) The major difference between home made and purchased light boxes is that the ones bought from reputable manufacturers have an ultraviolet filter built in. Without such a filter, use of the light box increases the possibility of skin cancer and cataracts. Among the better manufacturers are: Sunbox, Northern Lights, and Apollo.
3) When doing light therapy, make sure you are close enough to the light box to get 10,000 lux of light. Check the instructions that came with your unit to see exactly what distance your eyes should be from the box. With most boxes the correct distance is 18-24 inches from the light. Do not estimate, get a tape measure and make sure that your are sitting the correct distance from the lightbox. It is OK to read or knit while sitting in front of the lightbox, just make sure that you can see the lightbox clearly in the periphery of your vision with both eyes, while you are reading or knitting. Some people report that the time they spend in front of the light box is more beneficial if, once a minute, they look up from whatever they are doing, and look directly at the light for a fraction of a second.
4) Optimally the lightbox should be used first thing in the morning. Some people find that use of a light box late in the day makes sleep difficult. Most people with a seasonal component to their depressions improve with 20 to 30 minutes in front of the lightbox every morning. A few people have discovered that they require an hour a day.