1. Circadian, Neuroendocrine and Sleep Disorders Section, Endocrinology-Hypertension Division, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston 02115;
2. Division of Applied Sciences, Harvard University, Cambridge 02138; and
3. Department of Ophthalmology, Harvard Medical School and Massachusetts Eye and Ear Infirmary, Boston, Massachusetts 02114