Do the dark winter days make you want to crawl back into bed? Up to 6 percent of Americans suffer from seasonal clinical depression, known as seasonal affective disorder (SAD). Another 10 to 20 percent experience a less-serious version, sometimes referred to as the winter blues. If your mood changes with the weather, you may be able to brighten your outlook with light therapy. Basking in the glow of a light-therapy box for several minutes a day has been shown to alleviate symptoms of seasonal depression. Look for a device that emits at least 10,000 lux of light. Shine the lamp on your face, but don’t look directly into the light. Sit in front of it for about 20 to 30 minutes a day, usually first thing in the morning. Some people using light therapy could experience headaches or mania, so always check with your doctor to be sure it’s right for you. Anyone with vision problems should also consult their eye doctor before using a light box.