A system for detecting abnormal eye movement in a subject to indicate possible impairment of the subject. The subject may be presented with a visual pattern to observe. The visual pattern may cause the subject's eyes to move. Images of the eye movements may be captured. An eye motion pattern may be computed from the images. The eye motion pattern may be classified relative to other eye motion patterns or a guide. The classification may indicate whether there appears to be an abnormal movement of the eye and thus an impairment of the subject. An identification of the subject may be obtained according to a biometric from the images and used to retrieve the subject's baseline eye motion pattern. A comparison of the computed eye motion pattern and the baseline eye motion pattern may indicate whether there is abnormal movement of the eye and thus an impairment of the subject.