The horizontal gaze nystagmus test is one of three
field sobriety tests standardized by the National Highway Traffic Safety Administration. An
officer may use this test during a DUI stop to assess the subject's
condition. If an officer performed the horizontal gaze nystagmus test
during your traffic stop, resulting in your
DUI case, you may benefit from consulting with an Orange County DUI lawyer.
The test requires the officer to evaluate the rhythmic oscillation of the
subject's eyeballs. Though all people normally have slight, involuntary
oscillation of their eyes, a more pronounced motion may signify the presence
of alcohol in the subject's system. The officer looks for clues to
show a horizontal gaze nystagmus: a jerky, sporadic movement of the eye
toward the direction of the subject's gaze.
The test relies on three clues to show a horizontal gaze nystagmus. The
officer looks for: (1) a lack of smooth pursuit; (2) distinct nystagmus
at maximum deviation; and (3) the onset of nystagmus prior to an angle
of 45 degrees. The officer makes two passes and identifies each of the
three clues during each pass, which allows for a total of six clues. If
the officer notices at least four clues, the officer may determine the
blood alcohol concentration as higher than 0.10 percent.
Barney Gibbs may be able to assist you in challenging the results of a
horizontal gaze nystagmus test in your case. A lawyer may argue that interference
from strobe lights, rotating lights, or the lights of passing cars may
have changed the motion of your eyes. A lawyer may also try to cast doubt
onto the test by explaining that dust and other irritants may have affected
your eye movements. Furthermore, your lawyer may explain that other causes,
including consumption of caffeine, nicotine, or aspirin, as well as fatigue,
may lead to a nystagmus.
If you are facing a DUI trial, do not hesitate to contact experienced Orange
Country DUI lawyer Barney Gibbs today to schedule a
free initial consultation. I may be able to help you with your legal case.