What is the maximum number of clues for Horizontal Gaze Nystagmus that can appear in one eye?

The maximum number of clues for Horizontal Gaze Nystagmus (HGN) that can appear in one eye is indeed three. During the HGN test, an officer observes the subject's eyes while they follow a stimulus (typically a pen or flashlight). The clues that an officer looks for include:

1. The inability of the eyes to smoothly track the stimulus.

2. Distinct and sustained nystagmus at maximum deviation.

3. Onset of nystagmus before the stimulus reaches a 45-degree angle.

As each eye is examined separately, a maximum of three clues can be noted for each eye, leading to a total of six clues when both eyes are evaluated. This quantifiable aspect helps law enforcement officers determine whether an individual may be under the influence of alcohol or drugs based on the presence of these clues. Understanding the scoring system and the specific clues helps officers make informed decisions during DUI investigations.