Nystagmus Test Procedures

Nystagmus Test Procedures, Horizontal Gaze Nystagmus, Vertical Gaze Nystagmus, standardized field sobriety tests, New Jersey, Driving While Intoxicated, DWI, Driving Under the Influence, DUI, drunk driving, Atlantic County, Bergen County, Burlington County, Camden County, Cape May County, Cumberland County, Essex County, Gloucester County, Hudson County, Hunterdon County, Mercer County, Middlesex County, Monmouth County, Morris County, Ocean County, Passaic County, Salem County, Somerset County, Sussex County, Union County, Warren County, criminal defense, traffic ticket, juvenile, attorney, lawyerAn Elizabeth, NJ, cop recently admitted to causing the death of a motorcyclist while driving drunk last Halloween. The officer admitted in court to drinking at a bar in Roselle, NJ, before the crash, per the news. While operating his vehicle under the influence of alcohol, he caused a collision with the motorcycle. A police narrative alleges he left the accident scene after giving police his credentials, per nj dot com. Court documents further allege he prevented police from searching his vehicle, per the news.

The officer pleaded guilty to third degree strict liability vehicular homicide, fourth degree tampering with physical evidence, and driving while intoxicated, per the news.

Horizontal Gaze Nystagmus Test Procedures

To establish probable cause for a DUI arrest, and ostensibly to prove the operator was under the influence, police perform Standardized Field Sobriety Tests (SFST). Included in this battery of tests are the Horizontal Gaze Nystagmus test procedures. Along the way, the officer should rule out non-alcoholic etiologies for involuntary nystagmus.

Horizontal Gaze Nystagmus (HGN) Instructions

The officer should instruct the subject by stating, in effect, I am going to check your eyes. Keep your head still and follow the stimulus with your eyes only. Continue to follow the stimulus with your eyes until I instruct you to stop. Additionally, the motorist should remove any eyeglasses.

HGN and Medical Impairment

Assessments for medical etiologies include examining pupil size, resting nystagmus, and tracking ability. The likelihood of medical disorders or injuries causing nystagmus increases when the pupils are noticeably unequal in size, if resting nystagmus occurs, or if the eyes do not track together while following an object. Seizure medications and some other drugs can also cause nystagmus. The officer ought to perform these assessments before beginning the nystagmus test procedures.

To test for medical impairment, the officer ought to position the stimulus about 12 to 15 inches from the subject’s nose. Additionally, positioning the stimulus slightly above the subject’s eye level means the eyes will be wide open when looking directly at it. Furthermore, the officer should examine the size of the pupils because unequal pupil sizes could result from a head injury. Moreover, the officer should test whether the pupils track the stimulus together. Indeed, a medical disorder, injury, or blindness can cause the eyes to follow the stimulus separately instead of together. The officer should also look for resting nystagmus.

Smooth Pursuit

Checking the subject’s left eye for horizontal gaze nystagmus requires moving the stimulus to the officer’s right. While moving the stimulus smoothly, two seconds ought to pass for the subject’s eye to reach as far to the side as possible. Likewise, testing the right eye requires moving the stimulus smoothly all the way across the subject’s face to the officer’s left. While moving the stimulus, the officer ought to watch the subject’s eye for smooth pursuit. The officer should do this twice.

Distinct and Sustained Nystagmus at Maximum Deviation

To check for distinct and sustained nystagmus at maximum deviation, the officer should move the stimulus to the subject’s left until the eye can move no further. The officer should hold this position for four seconds. Likewise, the officer should move the stimulus all the way across the subject’s face to the motorist’s right, and hold this position for four seconds. During the four second holding period on each eye, the officer should look for distinct and sustained nystagmus. The officer ought to do this twice. Notably, distinct and sustained nystagmus may begin after positioning a subject’s eyes at maximum deviation for more than 30 seconds.

Onset of Nystagmus Prior to 45 Degrees

The officer should begin moving the stimulus to his right, reaching the edge of the subject’s shoulder in about four seconds. Likewise, the officer should move the stimulus to his left, also reaching the edge of the subject’s shoulder in about four seconds. If the officer observes a jerking motion in the eye during either pass, the officer should stop and verify the jerking continues.

Vertical Gaze Nystagmus Test Procedures

The Vertical Gaze Nystagmus Test procedures require the officer to look for jerking as the eye moves up and are held at maximum elevation for about four seconds.

After positioning the stimulus horizontally, about 12 to 15 inches in front of the subject’s nose, the officer should instruct the subject to hold his head still and follow the stimulus with the eyes only. Next, the officer should raise the stimulus until the subject’s eyes are elevated as far as possible. While holding the stimulus for approximately four seconds, the officer should watch for evidence of jerking.

Defending a person charged under the DUI statute requires the ability to analyze the officer’s administration of the tests. Of course, that requires a thorough knowledge of these tests as well as the law. And while I hope everyone passes these tests with flying colors, if the officer decides you failed, NJ Drunk Driving Lawyer Michael A. Smolensky, Esquire, knows how to protect his clients. Mr. Smolensky can provide consultations on all cases involving DUI. Call Now—(856) 812-0321.