Comprehensive Arizona DUI Information
DUI EYE TESTING
In Arizona
WHAT IS HORIZONTAL GAZE NYSTAGMUS?
The Horizontal Gaze Nystagmus test (HGN) is the eye test that officers give you roadside when they are doing a DUI investigation.
DO I HAVE TO TAKE THE EYE TEST?
Like all field tests, the answer, in Arizona, is no. If you refuse, the officer will likely arrest you. However, it is better to be arrested before, rather than after the test. Why? Because if you take the test, the prosecution and cops will try to make the result that the officer records (nearly always a "fail") seem like irrefutable evidence of your guilt.
HOW ARE OFFICERS IN ARIZONA TRAINED IN HGN?
Most officers take a weekend length class in the curriculum prescribed by NHTSA (National Highway Traffic Safety Administration). The class consists of roughly 20 hours of classroom and "hands on" experience. Here's a dirty little secret... I have never met anybody who fails the testing at the end of the course and does not graduate, and I defy any prosecutor or police officer to name one currently employed police officer who has.
Once the officers do their initial HGN training (which is combined with training on the One Leg Stand and Walk and Turn tests), then they must get experience in the field. They must do approximately 20 total tests before they are deemed certified to testify about the test in court.
Keep in mind that DUI officers are trained by other police officers. They are not trained by doctors or neurologists to diagnose nystagmus, which is essentially what this field test asks them to do.
HOW CAN I COMBAT THE COP'S ASSERTION THAT I FAILED?
Any DUI defense lawyer worth his/her salt will be well versed in this test, and able to recite numerous alternative causes for the phenomenon of nystagmus (other than, of course, alcohol). Some of the causes include:
- problems with the inner ear labyrinth;
- irrigating the ears with warm or cold water under peculiar weather conditions;
- influenza;
- streptococcus infection;
- vertigo;
- measles;
- syphilis;
- arteriosclerosis;
- muscular dystrophy;
- multiple sclerosis;
- Korchaff's syndrome;
- brain hemorrhage;
- epilepsy;
- hypertension;
- motion sickness;
- sunstroke;
- eye strain;
- eye muscle fatigue;
- glaucoma;
- changes in atmospheric pressure;
- consumption of excessive amounts of caffeine;
- excessive exposure to nicotine;
- aspirin;
- circadian rhythms;
- acute trauma to the head;
- chronic trauma to the head;
- some prescription drugs, tranquilizers, pain medications, anti-convulsants;
- barbiturates;
- disorders of the vestibular apparatus and brain stem;
- cerebellum dysfunction;
- heredity;
- diet;
- toxins;
- exposure to solvents, PCBS, dry cleaning fumes, carbon monoxide;
- extreme chilling;
- eye muscle imbalance;
- lesions;
- continuous movement of the visual field past the eyes;
- antihistamine use.
The point is this: how can any officer, who is not trained in medicine or neuroopthamology distinguish between any of the above 39 other possible causes of HGN, and alcohol as a cause? The answer is simple, he/she can't. It is your DUI defense attorneys job to make the Judge and Jury see and understand this simple fact.