Virginia Horizontal Gaze Nystagmus Test

If you have recently been arrested for driving under the influence in Virginia, you were probably asked to take a few field sobriety tests by the police officer. These field sobriety tests are used to determine whether a DUI arrest should be made.

The National Highway Traffic Safety Administration has approved three standardized field sobriety tests: the walk-and-turn, the one-leg stand, and the Horizontal Gaze Nystagmus test.

Horizontal gaze nystagmus is basically the jerking of your eyes. Nystagmus typically occurs when you look to the side as far as you can. However, if a person is intoxicated, nystagmus will occur before your eyes reach a high peripheral angle. The jerking will also appear more pronounced if the person is drunk.

To administer this test, the police officer will ask you to follow a small object such as a flashlight with your eyes without moving your head. During this test, the officer is looking for several things: inability to smoothly follow the object, jerking that starts at a 45 degree angle, and jerking that occurs at the maximum deviation. The officer is watching for three signs in both eyes, for a total of six signs. If he or she notices four or more factors, it is assumed that your BAC is at least 0.10 percent or higher (well over Virginia’s limit of 0.08 percent).

The horizontal gaze nystagmus field sobriety test is also used by law enforcement to test for the presence of barbiturates and depressants.

While this test is known as the most scientific of all three field sobriety tests, it is far from perfect. Nystagmus can have hundreds of causes other than alcohol consumption. Vision problems, tumors, and neurological problems may result in nystagmus.

If you have taken the horizontal gaze nystagmus test and failed, there is still hope. There are many people who suffer from natural nystagmus. The police officer may also have improperly administered the test.