During the HGN test, what action is typically required of the subject?

The Horizontal Gaze Nystagmus (HGN) test requires the subject to follow an object, typically a pen or a similar stimulus, with their eyes while keeping their head still. This action allows the officer conducting the test to observe the eyes for specific involuntary movements known as nystagmus.

During the test, the officer moves the object horizontally in front of the subject, and the subject's ability to maintain focus on the object with their eyes is assessed. The presence of nystagmus can indicate impairment, as it may suggest the influence of alcohol or other substances. Keeping the head still is essential to ensure that the test results are valid, as any movement of the head can affect the visual observation of the eyes' reaction.

In contrast, turning the head slowly, reaching for the object, or moving the arms does not accurately assess the eyes' ability to track movement and would not provide the necessary indicators for determining impairment related to alcohol or drug use.