How many validated clues are there for the HGN test?

The Horizontal Gaze Nystagmus (HGN) test, which is commonly used in assessing impaired driving, involves the observation of the eyes as they follow a moving object. There are three validated clues that the officer observes during the test. These clues help identify signs of potential alcohol or drug impairment. Specifically, the officer looks for:

1. The absence of smooth pursuit in one or both eyes.

2. The presence of distinct and sustained nystagmus at maximum deviation in each eye.

3. The onset of nystagmus before 45 degrees in each eye.

The identification of these clues allows law enforcement to make a more informed evaluation of a driver’s level of impairment. Understanding the HGN test's validated clues is crucial for officers to correctly administer the test and analyze the results effectively. Recognizing these cues also aids in ensuring that officers adhere to standardized assessment methods, which are essential for maintaining the validity and reliability of the tests used in impaired driving cases.