Bright Light therapy is used to tread S.A.D. (Seasonal Affective Disorder). S.A.D. is a disorder which affects people in the winter, when sunlight is infrequent. Bright light therapy treats many disorders, these include acne, jaundice, some psychiatric disorders such as depression, delayed sleep phase syndrome, and Parkinson's disease. The bright light therapy helps people all the way from infants to older adults.