Slow vestibulo-ocular reflex (VOR): Since smooth pursuit and VOR systems are both active, if eye movements are choppy with this maneuver this implies deficits in both pursuit and the vestibular system as in CANVAS; Fast (HIT): Since smooth pursuit fails at high frequencies and high speeds, the VOR is isolated during the HIT even with the lights on; if the eyes initially move with the head during the HIT and then make a "catch-up" saccade back to the examiner's nose (in the opposite direction to the head movement), this is a + HIT toward the side of the rapid head movement and generally indicates a peripheral localization Instructional ocular motor examination procedures.