A system and method are provided for optical detection of cognitive impairment of a person using a portable video capture device (PVCD). In one embodiment, the method includes: (i) capturing video of an eye exposed to light stimuli over a predetermined time using a video camera of the PVCD (ii) processing the video to locate at least one feature of the eye (iii) measuring a change in the feature in response to the light stimuli (iv) analyzing data from the measured change in the feature by extracting data from the measured change in the feature, calculating a number of parameters from the extracted data, correlating the calculated parameters with predetermined reference parameters and predicting a degree of impairment based on the results of the correlation and (v) outputting through a user interface in the PVCD the degree of impairment to a user. Other embodiments are also described.
