A portable ocular response testing device includes a portable housing, a plurality of lights for generating visible light within two eye spaces of the portable housing, a controller for operating the lights according to a prescribed pattern, and an imaging system to capture images of the eyes under varying lighting conditions to evaluate an ocular response of a user to the lighting conditions. In some instances, the portable device is used in the field of ophthalmology for complete assessment of optic nerve defects producing Marcus-Gunn pupil, detection and quantification of color blindness, and detection and follow up of eye abnormalities. In other instances, the device is adapted for screening of driving under influence (DUI) or Driving While Intoxicated (DWI) by performing multiple eye tests resulting in field screening of DUI or DWI cases.
