Daily Light Exposure for Sleep Disturbance, Fatigue, and Functional Outcomes in Acute Brain Injury

Inclusion Criteria: 1. Inpatient admission to St. Luke's Rehabilitation Institute for stroke, traumatic brain injury, or non-traumatic brain injury 2. Male or female, 18 to 85 years of age (to match limits of assessment instruments) 3. Able to provide written informed consent or have a legally authorized representative that can provide written informed consent 4. Stable neurologic status, as determined from subject's medical records and the study physician's opinion based on no new or changing symptoms 5. Normal vision or corrected to normal vision (if glasses or contacts are tinted, willing to remove during light exposure) 6. Normal hearing or corrected to normal hearing 7. Willing to complete baseline evaluations prior to inclusion in the study to include: sleepiness inventories, neuropsychological testing, self-report fatigue assessment Exclusion Criteria: 1. History of epileptic or other seizure disorder 2. Cataract surgery in the past 12 months 3. Significant visual impairment affecting light reaching the retina/performance of the retina: cataracts, macular degeneration, diabetic retinopathy, congenital blindness, total blindness, glaucoma, or retinal detachment 4. Endorsement of suicidal ideation on the PHQ-9 depression screen (standard of care admission assessment at St. Luke's) 5. Pre-injury diagnosis of a sleep disorder, including: sleep apnea, insomnia, narcolepsy or periodic limb movement syndrome 6. Neurological disorders other than those attributed to the primary diagnosis, including multiple sclerosis, Parkinson's disease, Huntington's disease, Alzheimer's disease or other dementias, amyotrophic lateral sclerosis) 7. Bipolar diagnosis 8. Females who are pregnant as determined from subject's medical records or who are breastfeeding 9. In active withdrawal from alcohol or street drugs 10. Unwillingness to refrain from wearing tinted glasses or contact lenses during light exposure