The purpose of this study is to assess the safety and efficacy of daily morning exposure to colored light in patients receiving acute inpatient rehabilitation services for stroke, traumatic brain injury, or non-traumatic brain injury with sleep disturbances such as poor nighttime sleep and/or excessive daytime sleepiness.In a two-arm randomized placebo-controlled study with pre-exposure and post-exposure assessments, we are comparing the effects of daily morning exposure to either blue light or red light on objective sleep quality, subjective sleep quality, functional rehabilitation outcomes, cognitive symptoms, fatigue, and neurological symptoms.

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