HGN stands for Horizontal Gaze Nystagmus and is one of the three field sobriety tests given when you get pulled over for a DWI.
This test determines the movements of your eyes to gather information on whether or not you may be intoxicated.
The federal government came up with three standardized tests that all the scientific so-called experts thought were valid and reliable to prove if someone was intoxicated. The first one is HGN: Horizontal Gaze Nystagmus. Horizontal meaning just that, horizontal, gaze meaning they look into your eyes, nystagmus is the involuntary jerking of your eyes, and there’s the old saying when they’d teach this to police officers, the eyes don’t lie. If your eyes jerked back and forth, they determined that there may be a level of intoxication.
The way the test is given is that the police office will hold a pen or other stimulus 12 to 18 inches from your face. The officer has to give you precise instructions. He will start with the left eye. He will move the pen, and you are to follow the pen with your eyes, and if your eyes start to jerk back involuntarily before they get to your nose – that’s 45 degrees – that’s one clue. If your eyes without moving your head cannot equally track or equally follow the pen, that’s clue number two. The third clue is maximum deviation. That means when the pen requires your eye to go all the way to that side of your wall eye socket and it can’t stay there, and if it’s there and it jerks back and forth, it’s called maximum deviation nystagmus. Six clues, three for each eye.