What Is a Nystagmus Test?
The term “nystagmus” refers to involuntary movement of the eyes. A nystagmus test measures the involuntary bouncing or jerking of the eyeball. It is conducted by asking the person being tested to follow with his or her eyes the path of an object, such as a pen or a small flashlight, back and forth about 12-15 inches (about 30-38 cm) in front of his or her face. The most common use of this test is as part of an investigation to determine whether a person was driving while intoxicated (DWI) or driving under the influence (DUI). If the subject of the nystagmus test fails the test, he or she might be arrested for DWI or DUI. If a driver commits a traffic violation, a police officer can legally stop that driver to begin an investigation. While talking to the driver, the police officer will be making observations about the driver. If the driver has trouble producing his or her driver’s license and vehicle registration, smells of alcohol or has bloodshot eyes, the police officer might ask the
