Inclusion Criteria:  Age 13-45 years Presents to the facility within 2 weeks of head trauma  Able to provide informed consent  If minor, then able to provide parental consent and minor assent Able to participate in the examination, including the ability to follow simple instructions Fluency in English or Spanish  Exclusion Criteria:  Glasgow Coma Scale score of equal to or less than 13 at the time of study enrollment Under the influence of alcohol or drugs Previous eye surgery Visual acuity known to be 20/200 or less in either eye Known strabismus, amblyopia (lazy eye), or double vision Known eye movement disorder, including nystagmus Known optic nerve disease, including papilledema or optic neuropathy Known retinal disease, including macular degeneration or retinal degeneration Known cataract History of neurosurgery History of stroke/brain hemorrhage, brain tumor, or epilepsy Any head trauma requiring medical attention from a physician within the last 6 months Diagnosed dementia or cognitive impairment requiring assistance for daily living Other condition(s) under the care of a neurologist Psychiatric hospitalization in the last 90 days Subject considered unsuitable for participation in this clinical trial by PI, treating clinician, or study research staff Any minor brain injury regardless of loss of consciousness