• diagnostic accuracy of initial clinical diagnosis of concussion [ Time Frame: day 0 (when patient first presents for evaluation) ]
  sensitivity and specificity compared to initial clinical diagnosis of concussion
• diagnostic accuracy of clinical diagnosis of post-concussion symptoms [ Time Frame: up to one year after initial presentation ]
  sensitivity and specificity compared to clinical diagnosis of post-concussion symptoms
• adverse events [ Time Frame: through study participation, up to one year ]
  adverse events occurring during use of the diagnostic device

• diagnostic accuracy of initial clinical diagnosis of concussion [ Time Frame: day 0 (when patient first presents for evaluation) ]
  positive and negative predictive value compared to initial clinical diagnosis of concussion
• correlation with increases or decreases in post-concussion symptom severity [ Time Frame: up to one year after initial presentation ]
  diagnostic accuracy to identify increases or decreases in post-concussion symptom severity

• Concussion, Brain
• Mild Traumatic Brain Injury

Inclusion Criteria:

1. Provide written informed consent or assent along with guardian consent.
2. Have sustained a suspected direct or indirect force to the head with or without documented loss of consciousness, memory loss, alteration in consciousness or neurologic deficits. Only individuals presenting for initial evaluation of concussion may be enrolled, however longitudinal assessments may be conducted on enrolled subjects.
3. Have the ability to provide a complete ophthalmologic, medical and neurologic history as well as report medications/drugs/alcohol consumed within the 24 hours prior to tracking.

Exclusion Criteria:

1. Have penetrating trauma.
2. Have had a conventional head CT or MRI demonstrating evidence of structural brain injury (subdural, epidural or intraparenchymal hemorrhage, edema/mass effect per attending radiologist read).
3. Either of the following conditions, immediately related to the incident head trauma: loss of consciousness exceeding 30 minutes or best available GCS score less than 13 within 24 hours.
4. Be blind (no light perception), have missing or non-functional eyes.
5. Be unable to open their eyes.
6. Have a history of unresolved strabismus, diplopia, amblyopia.
7. Have a history of unresolved cranial nerve III, IV, or VI palsy.
8. Have a history of unresolved macular edema, retinal degeneration, extensive cataract, or ocular globe disruption.
9. Have a history of extensive prior eye surgery (examples include strabismus surgery, scleral buckle repair of retinal detachment, repair of blow out fractures of the orbit and any procedures that would interfere with extraocular muscle movements; prior cataract surgery or Lasik are not exclusions) or scarring.
10. Have a prior history of unresolved ocular-motor dysfunctions.
11. Be intoxicated.