What is the recommended position of the stylus when checking for HGN?

The recommended position for the stylus when checking for Horizontal Gaze Nystagmus (HGN) is indeed 12-15 inches from the subject's nose. This distance is critical because it allows for an optimal field of vision to assess the eyes effectively without causing discomfort or straining the subject. By maintaining this specified distance, officers can better observe the involuntary jerking of the eyes, which is key for determining potential impairment. This range is designed to align with typical human eye movement capabilities and ensures that the test is performed under optimal conditions, thereby increasing the reliability of the results. Proper positioning is essential to accurately identify the signs of impairment and to ensure that the test results are valid and defensible.