  In this paper, we introduce a portable eye imaging device denoted as
lab-on-a-headset, which can automatically perform a swinging flashlight test.
We utilized this device in a clinical study to obtain high-resolution
recordings of eyes while they are exposed to a varying light stimuli. Half of
the participants had relative afferent pupillary defect (RAPD) while the other
half was a control group. In case of positive RAPD, patients pupils constrict
less or do not constrict when light stimuli swings from the unaffected eye to
the affected eye. To automatically diagnose RAPD, we propose an algorithm based
on pupil localization, pupil size measurement, and pupil size comparison of
right and left eye during the light reflex test. We validate the algorithmic
performance over a dataset obtained from 22 subjects and show that proposed
algorithm can achieve a sensitivity of 93.8% and a specificity of 87.5%.
