The Standard Field Sobriety Test (SFST) Includes the Horizontal Gaze Nystagmus test, which assesses the Involuntary jerking of the . as they move to the side. type your answer. __

## Step 1<br />The Standard Field Sobriety Test (SFST) is a set of tests used by law enforcement officers to determine if a person is under the influence of alcohol or drugs. The Horizontal Gaze Nystagmus (HGN) test is a part of this test.<br />## Step 2<br />The HGN test focuses on the involuntary jerking of the eyes as they move to the side. This is a physiological response that is affected by alcohol and drugs.<br />## Step 3<br />The test involves the subject following a moving object with their eyes while the officer observes the movement of the eyes. The jerking of the eyes is a sign of impairment.