If an Alaska police officer pulls you over at a traffic stop and asks you to step out of your vehicle, you can logically assume that you are suspected of driving under the influence of alcohol. The officer might ask you to take a special eye test, known as the horizontal gaze nystagmus test. If you wear contacts or have certain eye conditions or a past injury, it can impede your ability to perform the test well, which could, in turn, compel the person administering the test to issue a failing score and make a DUI arrest.
A horizontal gaze nystagmus test includes a list of instructions that require you to track an object left to right or vertically without moving your head. As you perform the test, the police officer administering it will closely observe your eyes. If you fail the test, it constitutes probable cause to arrest you for suspected drunk driving.
What causes you to fail a Horizontal Gaze Nystagmus test?
The human eye has a maximum peripheral vision point, meaning the ability to focus on an object horizontally or vertically, moving only the eyeballs, not the head. If you are intoxicated, there may be an exaggerated nystagmus, which is an erratic movement of the eyeball, while you are tracking an object using only your eyes. While every person’s eyes have some degree of nystagmus, jerking or shaking of the eyeball occurs sooner in an intoxicated person than it might in a sober person.
If you are taking a horizontal gaze nystagmus test, the person administering the test is closely monitoring your eyeball movement. If he or she believes that you have exhibited nystagmus jerking to such a degree as is common for an intoxicated person, you might wind up being taken into police custody for suspected DUI.
Such tests are often inaccurate
Before administering a horizontal gaze nystagmus test, a police officer is supposed to ask you whether you wear contacts or have had an eye injury or a medical condition in your eyes that may impede your ability to perform the test. If you were arrested for DUI and were not asked any such questions before taking the test, you may be able to challenge the evidence in court if your case goes to trial.
You will also want to be aware that you are not obligated to take a horizontal gaze nystagmus test or any other field sobriety test during a traffic stop. An Alaska police officer is free to request it, but you are also free to decline. Whether you take a test or not, if you are arrested for DUI, it is always helpful to secure defense support, as soon as possible.