Concord Trial Attorneys

Understanding The Vertical Gaze Nystagmus Test

Being pulled over by the police is a very stressful situation to be in. Many thoughts and concerns run through a driver’s mind, and one of them is likely whether an officer will think he or she is under the influence of alcohol. We have all seen in on television and in the movies. Suspecting officers will ask the driver to exit the vehicle and begin the field sobriety test.

This test, which consists of various tests to provide evidence to support the presumption of intoxication, is frequently used during a DUI stop. But many drivers may not fully understand why these tests are conducted and what they really entail.

Take for example the vertical gaze nystagmus test. This tests looks at the involuntary jerking of the eyes. Before beginning the test, the officer should look at the suspect’s pupil size, resting nystagmus and his or her ability to track an object. This helps to evaluate possible medical impairments. If no impairments exist, then the test will proceed.

The officer will hold a small stimulus, such as a penlight, roughly 12 to 15 inches from the suspect’s nose. Then, the officer will instruct the suspect to keep his or her head still while following the stimulus with only their eyes as the officer moves it up and down and side to side. The officer is looking for various clue, such as a problem following the object smoothly.

Even if an officer believes a driver is intoxicated base don this or any other field sobriety test conducted, motorists should understand that they have defense options. If the test was not conducted properly or a step was missed, it is possible to challenge it. This could result in reduced or even dismissed charges.

Source:, “Vertical Gaze Nystagmus,” Accessed Dec. 2, 2017