Morning Light Treatment at Home to Reduce PTSD Symptoms

Inclusion Criteria: * Probable PTSD based on the PCL-5 score * Fluent in English * Willingness and ability to comply with the protocol Exclusion Criteria: * Current or recent (past 6 months) alcohol or substance abuse problems * Past or present psychotic or bipolar disorders * Significant suicidal ideation or suicidal behaviors in past 6 months * Unable or unwilling to give written informed consent. * Severe hearing and memory problems. * Cognitive impairment or mental retardation that interferes with subject being able to understand study requirements, consent form, etc. * Special events (e.g. weddings, exams, surgery) planned during 5 weeks of study * Unable to travel for study visits * Pending legal cases/litigation * Has a serious or unstable medical illness (including but not limited to cardiovascular disease, uncontrolled diabetes, advanced liver disease, kidney failure, seizures, cancer which is likely to result in hospitalization in next year). * Reports significant chronic migraine. For migraines, subjects will only be excluded if they report that bright light can trigger migraines. * Vision problems, retinal disease, or history of eye surgery. * Taking photosensitizing medications * Have previously had light treatment. * Uncontrolled narcolepsy, sleep apnea or restless leg syndrome * Likely to have undiagnosed, significant sleep apnea * Likely to have undiagnosed, significant restless leg syndrome * Prescribed hypnotics, over the counter sleep aids and antidepressants permitted providing all medications stable for 30 days before and during the study). All current medications must be non-photosensitizing. * If in psychotherapy must have been for at least 30 days. * People taking melatonin will be asked to abstain for a month before and during the study * Has traveled outside the central time zone * Have worked a night-shift the past month. * Has winter depression * Is pregnant, trying to get pregnant or breastfeeding. * Household has a child \<2 years old or a child that does not sleep through the night * Is unavailable for a 5 week period * Fail urine drug test at screening visit (after prescribed medication accounted for)