The proposed project will determine if patients with light sensitivity due to migraine headache have increased sensitivity to cone stimulation, melanopsin stimulation, or both. This pre-registration document was submitted on 4/17. At that point, we had begun screening potential subjects but not yet begun collection of any archival data. The pre-registration document was uploaded by HMM. An addendum to the pre-registration document was uploaded on 10/1/2018 by EAK. This addendum describes an additional cohort of individuals with traumatic brain injury to be studied and also provides a number of clarifications and refinements to our on-going experiment. An additional addendum was uploaded 5/14/2019 by HMM. This addendum describes our procedure to look at the pupillometry data collected thus far to re-evaluate the targeted enrollment, in light of slower than anticipated data collection. As stated in the addendum, note that all investigators involved in the analysis of this pupillometry data will remain masked as to the group assignment of any particular subject. On 6/28, an addendum was uploaded by HMM that describes our procedure to re-evaluate our power analysis. We have ultimately determined to have 20 subjects within each group.