Horizontal Gaze Nystagmus Administration

Horizontal Gaze Nystagmus Administration

If you have been charged with DUI, it is likely that you underwent a field sobriety test prior to your arrest. The first and most commonly administered field sobriety test is known as the horizontal gaze nystagmus test. Performance on the test is highly subjective; if you were arrested after this test was administered, your Orange County DUI lawyer may have a strong defense from which to argue your case.

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If an officer is administering the horizontal gaze nystagmus test, he will ask you to follow a pen or his finger with your eyes without moving your head. While observing your eye movements, he is trained to look for very specific indications of intoxication. However, as a human, the officer is susceptible to error, and the test relies solely on his observation and judgment.

How Is The Test Administered?

If he is administering the test correctly, the officer will direct you to do the following:

1.      Remove your glasses if you are wearing them.

2.      Put your hands at your side and place your feet together.

3.      Keep your head immobile for the duration of the test.

4.      Look at the “stimulus,” usually the tip of the officer’s finger.

5.      Follow the stimulus only with your eyes as he moves it.

6.      Continue to follow the stimulus until the officer tells you to stop.

The officer will then place the stimulus 12-15 inches in front of your nose, just above eye level. If the officer failed to take any of these steps, then the results of the test can be challenged. An Orange County DUI lawyer can tell you whether or not the test was conducted properly in your case.

What Is The Officer Looking For?

The officer is looking for the following signs of intoxication:

1.      Uneven tracking of the eyes.

2.      Uneven pupil size.

3.      Lack of smooth pursuit. The officer should take about two seconds to move the stimulus all the way to the edge of your vision, and another two seconds to bring it back to center.

4.      Distinct nystagmus at the extremes. Nystagmus is an involuntary tremor of the eye. Nystagmus at the extremes is naturally present in a significant minority of the population, even when sober.

5.      Onset of nystagmus before 45 degrees. This test measures how quickly nystagmus begins. Usually, a sober person will have a brief period of nystagmus after 45 degrees, which will then even out at the extremes. However, officers will never use any type of device to measure the angle, relying instead on their “training.”

6.      Vertical nystagmus. The officer will also look for nystagmus when having you follow a stimulus up and down.

Even if the officer conducts the test perfectly, that does not mean that his findings are unassailable. If you have been arrested following the administration of this test, the skilled Orange County DUI lawyers at the Law Office of Mike Coffey Attorney at Lawand the Law Office of Mike Coffey Attorney at Laware ready to help you with your case. Call (800) 706-7888 today to schedule a consultation.