Sacramento DUI Lawyer Explains Nystagmus
An experienced Sacramento DUI attorney defines nystagmus as a side to side jerking movement of the eyeball. This occurs when the inner ear or the systems that control eyeball movement are disrupted.Nystagmus Can Occur Naturally
It is not unusual for the eyes to exhibit a small amount of involuntary movement under ordinary circumstances. Your Sacramento DUI attorney can explain that under HGN (Horizontal Gaze Nystagmus), the motion of the eyeball is not controlled by the subject. In fact, since the subject’s eyesight is not altered or affected by it, he or she has no knowledge that HGN is present.How the Test is Scored
The administering officer looks at three specific criteria (clues) when scoring this test:
- Jerkiness in pursuit
- Nystagmus that becomes obvious at the point of maximum deviation
- Nystagmus that begins before the 45-degree point.
Since the test is given twice, six scoring criteria are available. For the subject’s blood alcohol level to be deemed greater than 0.10 percent, four clues must be present.Issues That Affect Accuracy
Your Sacramento DUI attorney can point to several factors that can affect the accuracy or efficacy of the HGN test. Depending upon the conditions that exist at the scene, factors such as weather (wind), irritants such as dust or sand, lights from oncoming traffic, strobe lights or other distractions may contribute to nystagmus, as can fatigue and prescription or over-the-counter medications. Any of these can cause nystagmus whether alcohol is present or not, and the officer must be aware of this.Protect Yourself
If you have been subjected to the HGN test, don’t hesitate. Contact Param Pabla, your Sacramento DUI attorney via telephone or Skype at (916) 285-7900 today.