What is the second clue observed during the HGN test?

The second clue observed during the Horizontal Gaze Nystagmus (HGN) test is the distinct and sustained nystagmus at maximum deviation. This aspect of the HGN test is important because it indicates a significant level of impairment, as nystagmus refers to an involuntary eye movement that can reveal the presence of substances such as alcohol in the system.

When the eyes are moved to the farthest point of gaze, if nystagmus is distinctly visible and sustained, it suggests that the individual may be experiencing a degree of intoxication that affects their eye function. Recognizing this clue can aid law enforcement officers in determining the influence of alcohol on the driver's capabilities, contributing to a more accurate assessment during field sobriety tests.

Each stage of the HGN test builds upon the previous observations, and the presence of this clue is critical for evaluating a subject's sobriety reliably. The other choices, while relevant to the broader HGN test assessment, do not represent the second clue specifically, but instead refer to either earlier signs of impairment or balance issues that are considered at different stages of the evaluation.