Horizontal Gaze Nystagmus Test

When the police suspect that you are driving under the influence, they may pull them over for a traffic stop. Once both vehicles are safely stopped on the side of the road, the officer will attempt to determine whether or not you are under the influence of drugs or alcohol through various DUI tests. Commonly seen in movies and television, the horizontal gaze nystagmus (HGN) test is one of the methods often used to determine a driver’s level of intoxication.

If you are being accused of driving under the influence, you may be worried about the consequences you could face upon conviction. In Illinois, driving drunk is taken very seriously, with penalties including significant fines and a term of incarceration. Chicago DUI lawyer Michael O’Meara has over two decades of courtroom experience that he can put to use in your case. If the police used a horizontal gaze nystagmus test during your arrest, you may be able to challenge the basis for your arrest.

To find out more, call O’Meara Law today at 312-909-0706 for a free and confidential consultation.

What Is the Horizontal Gaze Nystagmus Test?

The HGN test is designed to provide officers with a general idea your blood alcohol content (BAC). However, it is in no way a definite indicator of intoxication or the amount of a substance in your body. The test relies upon a biological quirk in the human body that causes certain movements. Nystagmus is an involuntary twitching or jerking of the eye that is sometimes caused by depressants such as alcohol.

The test consists of the officer asking you to follow the movements of a pen light with your eyes. If your eyes twitch or pursue the light slowly, the officers may have reason to believe you are intoxicated. They may arrest you and take you into custody, where you will be given a formal BAC chemical test.

Is the Horizontal Gaze Nystagmus Test Accurate?

According to the National Highway Traffic Safety Administration (NHTSA), the HGN test is accurate, but only when administered properly. Unlike other non-standard field sobriety tests, such as estimating when 30 seconds has passed or reciting the alphabet backward, the HGN test is a standard field sobriety test that has been thoroughly researched. According to the NHTSA, when administered properly, the HGB test is accurate 77 percent of the time. That means 22 percent of the time the test is incorrect.

There are a number of requirements that officers must adhere to when administering these tests. For example, the driver’s eyes must be fully visible. If the penlight is not bright enough or if the officer is unsure of the results, the HGN test may be inconclusive. The driver should also never be facing oncoming headlights or bright street lamps because excessive light can cause nystagmus to occur.

Let Michael O’Meara Protect Your Freedom

If you were charged with DUI after a traffic stop that involved an HGN test, you should talk with an experienced Chicago criminal defense lawyer. It may emerge that the test was administered improperly, or that the officer did not have proper training. In such scenarios, this could mean that the officer lacked the proper basis to make an arrest, in which case your charges may be subject to dismissal.

Attorney Michael O’Meara has over 20 years of courtroom experience as both a prosecutor and a criminal defender. He can anticipate the prosecution’s strategy in order to construct a compelling defense. Regardless of the circumstances surrounding your case, he will fight to get you the best outcome possible.

To find out more about the defenses that may apply to your DUI case, call 312-909-0706 for a free consultation.