How many clues are identified for the Horizontal Gaze Nystagmus (HGN) test?

The Horizontal Gaze Nystagmus (HGN) test identifies a total of six specific clues that are observed during the assessment. This field sobriety test is based on the involuntary jerking of the eye as a person gazes sideways, which may indicate impairment due to alcohol or drugs. The six clues include:

1. Lack of smooth pursuit in the eyes when tracking a moving stimulus.

2. Distinct and sustained nystagmus at maximum deviation, which refers to the eye's shaking while being held at an extreme left or right angle.

3. Onset of nystagmus prior to a 45-degree angle of the gaze.

These clues are critical for law enforcement officers to assess as they provide measurable indicators of a subject’s potential intoxication. The identification and interpretation of these specific clues aid in forming a conclusion about the individual's level of impairment, making the HGN test a key component in standardized field sobriety testing.