Several prominent scientists have conducted research on the biological effects of gradually increasing light in wakening human subjects. Homo sapiens evolved to waken by sunrise, which is now recognized as a powerful biological signal. Experiments on normal human subjects and SAD patients have demonstrated that dawn simulation advances circadian phase, and can be effective in treating SAD (SLTBR, Abstracts, Vol. 12, 2000). A hypothesis explaining a major factor in the study of the cause of SAD, which has been gaining in popularity, is that patients are phase delayed. The BioBrite SunRise Clock™ was designed to provide dawn simulation by an attractive, practical and inexpensive device. In a clinical trial of the Clock in high school students conducted by Dr. Brainard and associates, it was found to be a popular and effective wakening device (SLTBR Abstracts, Vol. 10, 1998.)