Abstract: A Horizontal and Vertical Gaze Nystagmus test apparatus and method for detecting eye twitch of an impaired test subject, the apparatus being generally comprised of a target having a top end for the test subject to focus on and follow with at least one eye through a horizontal range of motion extending between a leftmost location and a rightmost location relative to a central transverse axis, and a through a vertical range of motion, the apparatus further including a base forming a template and support for the target, where the base includes means for positioning thereof relative to the face of the test subject and means for prescribing a uniform travel path for the target between the leftmost and rightmost locations, and the aforementioned vertical range of motion at a specified distance from the face of the test subject.