Glasses for Adolescent Delayed Sleep-Wake Phase Disorder

Inclusion Criteria * Regular school attendance in the setting of a fixed start time. * Adherence to ICSD-3 DSWPD diagnostic criteria. * Average spontaneous weekend wake time ≥1 hour than school day wake time. * Initiation of school-night sleep at 12 a.m. or later, ≥50% of the time, during a 14-day period (items 3-4 to be determined by sleep logs and actigraphy). As there are no discrete clock times associated with the ICSD-3 DSWPD description, this cutoff is based on data obtained from the 2006 Sleep in America Poll and experiences gleaned from prior recruitment. Exclusion Criteria * A positive urine drug abuse screen will disqualify the individual from further participation. * Subjects will be withdrawn from the study if the sleep log and wrist monitor activity does not correspond with the sleep schedule identified with the pre-study sleep log. * Alcohol and nicotine use will also be screened to qualify for the study. We will also screen for alcohol immediately before each DLMO assessment because alcohol acutely suppresses melatonin. * Patients receiving medications that might contribute to sleep disturbances and/or affect treatment responses will be considered ineligible (e.g., hypnotics, antidepressants, stimulants, non-steroidal anti-inflammatory drugs (NSAIDs), beta blockers). * All subjects will be asked to refrain from caffeine use on the days of phase assessments, and to cease ingestion at least 6 hours prior to nightly bedtime. * The Ishihara Color Blindness Test will be done and patients who are color blind/deficient will be disqualified from participating in the study.