Horizontal Gaze
Nystagmus HGN
The officer asks you to follow a moving object with your eyes while keeping your head still.
What the officer observes
The officer checks each eye for three clues:
- Lack of smooth pursuit
- Distinct, sustained jerking at maximum deviation
- Jerking that begins before 45 degrees
There are six possible clues across both eyes. A review can consider the officer’s training and how the test was administered.

