Reader’s Question:

I live in Las Vegas, Nevada and I was already asked to stop once because I was suspected to be intoxicated but I was not arrested. I passed the tests they asked me to do but I’m very much curious about one of the tests wherein they moved a penlight in front of my eyes, what is this kind of test?

Dale

Las Vegas, NV

You are lucky enough not to be arrested for DUI in Las Vegas, Nevada because if you will be convicted, the consequences are harsher than ever. But anyways, when you were asked to stop because of DUI and the officer moved a penlight in front of your eyes, this is one example of a standardized field sobriety test (FST) and is called the horizontal gaze nystagmus test (HGN). During this test, a driver will be asked to follow the light with the eyes. The officer would estimate the angle at which the eye twitches; if this happens at less than 45 degrees, it is considered a sign of high blood alcohol content (BAC).

HGN is relatively new to FST’s and they say that it is fairly accurate if administered properly. Nystagmus is an involuntary twitching of the eye and usually occurs when a person uses their peripheral vision by looking sharply to the side, at about 45 degrees, with the head held in the forward position. If a driver is under the influence of alcohol, the twitching occurs at a lesser angle and the person has difficulty following the object with his or her eyes.

Tags: DUI, DUI arrest, DUI lawyer, field sobriety tests