The purpose of this research study is to collect data from the eyes of traumatic brain injury (TBI) patients. Patients will look at a green target that will measure the fixation of the eye for 30 seconds. In that 30 seconds, the location of the green target will change and the participant is to track, with their eyes, the light as best they can. The device will measure how well fixation was maintained and the speed of the saccadic movements of the eye. Data will then be used to determine whether there is correlation between these measures and known TBI.

Inclusion Criteria:

1. Age ≥18-40
2. Documented/ verified mild TBI
3. Mild traumatic brain injury will be defined as Glasgow Coma Scale (GCS) of ≥13 at time of study enrollment
4. Injury occurred < 24 hours ago
5. Positive acute brain CT for clinical care
6. Visual acuity/ hearing adequate for testing
7. Fluency in English or Spanish
8. Ability to provide informed consent
9. Enrolled in TRACK-TBI (IRB #: 825503)

Exclusion Criteria:

1. Catastrophic polytrauma that would interfere with follow-up and outcome assessment
2. Prisoners or patients in custody
3. Pregnancy in female subjects
4. Patients on psychiatric hold (e.g. 5150, 5250)
5. Major debilitating baseline mental health disorders (e.g. schizophrenia or bipolar disorder) that would interfere with follow-up and the validity of outcome assessment
6. Major debilitating neurological disease (e.g. stroke, dementia, tumor) impairing baseline awareness, cognition, or validity of follow-up and outcome assessment
7. Significant history of pre-existing conditions that would interfere with follow-up and outcome assessment (e.g. substance abuse, alcoholism, HIV/AIDS, major transmittable diseases that may interfere with consent, end-stage cancers, learning disabilities, developmental disorders)
8. Low likelihood of follow-up (e.g. participant or family indicating low interest, homelessness or lack of reliable contacts)
9. Penetrating TBI
10. Spinal cord injury with ASIA (American Spinal Injury Assoc.) score of C or worse
11. Any injury to eye including, puncture, scratch, occlusion, fracture to orbital socket (or any fracture to face that would negatively impact eye movement/vision) that would interfere with ability to complete study-device assessment.
12. History of poor vision prior to injury (Visual acuity worse than 20/40 in either eye)
13. Intoxication or chemical impairment at time of examination (upon initial presentation)
14. Evidence on hand-light examination of obvious ocular anomaly or misalignment

Aggregate data and individual test reports will be made available to the HITT device manufacturer to better understand its performance at identifying TBI. Personal identifiable data will not be shared with anyone outside of the University of Pennsylvania.

Data will be shared on an ongoing basis, and cumulatively at the end of the study. Study length is expected to be 2 months from first enrolled participant.

Data will only be shared with researchers involved in the study at the University of Pennsylvania, and only trained staff members at the device manufacturer.