Some SAD sufferers insist they'd be fine if they could just be left alone to rest. But family, friends and employers tend to make hibernation difficult. Going south for the winter is rarely an option. Most commercial light boxes use full spectrum fluorescent bulbs that filter out ultraviolet rays. They don't overeat and oversleep so much.
Winter seems more manageable.
Light also has proved useful in treating shift workers, victims of jet lag and patients with sleep disorders. Side effects are rare, though some patients have reported headaches, eyestrain, irritability and insomnia. Nevertheless, many doctors remain skeptical. It doesn't help that sunlight also is a favorite New Age cureall, thought to have magical properties. And those most likely to seek light therapy also tend to have the most faith in it.