The horizontal gaze nystagmus test is a commonly used field sobriety test that helps law enforcement determine whether someone is drunk while driving. However, it’s important to note that this test is only sometimes reliable.
What is a Nystagmus Test?
The horizontal gaze nystagmus test is a usual field sobriety test that checks for nystagmus, the involuntary jerking of the eyes. This jerking can happen for various reasons but tends to be more noticeable when a person is intoxicated.
How Does the DUI Eye Test Work?
During the test, an officer will hold a pen or another small object about 12 to 15 inches from your face. The officer will then slowly move the object from side to side, asking you to follow it with your eyes while keeping your head still.
The officer will watch for eye movements that jerk or bounce while following the object, as well as nystagmus before your eyes reach a 45-degree angle or at the maximum angle of deviation. If the officer sees four or more signs of nystagmus, it may lead to probable cause for a DUI arrest.
Reasons for a Failed Test
The horizontal gaze nystagmus test is only correct about 77% of the time. Here are some reasons why someone might fail the test:
- You naturally have nystagmus in your eyes.
- You have a cold or an inner ear infection.
- You have been diagnosed with conditions like muscular dystrophy, multiple sclerosis, epilepsy, or glaucoma.
- You recently did activities that strained your eyes or caused eye muscle fatigue.
- You were taking certain medications, like pain relievers, anticonvulsants, or antihistamines.
- The officer moved the object too quickly for you to follow.
- The object was held too close to your eyes.
- You weren’t given enough time to follow the object during the test.
Also, if you drank alcohol several hours earlier, remember that nystagmus can still occur even after the alcohol has left your system.
Building a Strong Defense
Failing the horizontal gaze nystagmus test doesn’t mean you should panic. An experienced DUI defense lawyer can aid you in creating a solid defense by exploring all possible options to support your case. Contact us today to schedule a free initial case review with DUI attorneys at The Law Offices of Krum, Gergely, & Oates.
