Kirkland Seattle King County Drunk Driving DUI Lawyer: The Drug DUI Handbook

Kirkland Seattle King County Drunk Driving DUI Lawyer: The Drug DUI Handbook

Kirkland Seattle DUI / DWI / Drunk Driving Lawyers- Experienced, Successful, Affordable

(425) 493-1115

The following is an excerpt from the upcoming book “The Drug DUI Handbook,” due to be published in September, 2011.  Jolly, David N.  The Drug DUI Handbook.  Outskirts Press Inc. (2011)

Horizontal Gaze Nystagmus (HGN)

The technical definition of nystagmus is the rhythmic back and forth oscillation of the eyeball that occurs when there is a disturbance of the vestibular (inner ear) system or the oculomotor control of the eye. There are two major types of eye movements: pendular and jerk. Pendular nystagmus is where the oscillation speed is the same in both directions. Jerk nystagmus is where the eye moves slowly in one direction and then returns rapidly. Most types of nystagmus have the fast and slow phase (jerk nystagmus). Horizontal Gaze Nystagmus (HGN), which is the type of nystagmus used in DUI investigations, is a type of jerk nystagmus with the jerky movement toward the direction of the gaze. Adams, Raymond D. & Victor, Maurice. Disorders of Ocular Movement and Pupillary Function. Principles of Neurology. Ch.13, 117 (4th ed. 1991)

Like most types of nystagmus, HGN is an involuntary motion, meaning the person exhibiting the nystagmus cannot control it or is even aware of it. Forkiotis, C.J. Optometric Exercise: The Scientific Basis for Alcohol Gaze Nystagmus. 59 Curriculum II, No. 7 at 9 (April 1987); Good, Gregory W. & Augsburger, Arol R. Use of Horizontal Gaze Nystagmus as a Part of Roadside Sobriety Testing. 63 Am. J. of Optometry & Physiological Optics 467, 469 (1986); Stapleton, June M. et al. Effects of Alcohol and Other Psychotropic Drugs on Eye Movements: Relevance to Traffic Safety. 47 Q.J. Stud. On Alcohol 426, 430 (1986)

For information on your Washington State DUI / Drunk Driving, Snohomish County DUI, King County DUI, Skagit County DUI, Island County DUI or Whatcom County DUI  please contact our Washington State DUI drunk driving attorneys for a free consultation at 425-493-1115, email us at david@davidjollylaw.com, or check out our main website at http://www.washdui.com or www.mukilteodui.com, www.everett-dui.co, www.marysville-dui.com, www.dui-bothell.com, or www.anacortesdui.com.  We represent DUI clients in every court in Western Washington including Seattle DUI cases, Kirkland DUI cases, Redmond DUI cases, Shoreline DUI cases, Lynnwood DUI cases, Everett DUI cases, Mukilteo DUI cases, Marysville DUI cases, Mt. Vernon DUI cases, Anacortes DUI cases, and Bellingham DUI cases.

Author of The DUI Handbook for the Accused, DUI/DWI: The History of Driving Under the Influence, The DUI Investigation Handbook and The Drug DUI Handbook. 

Kirkland Seattle DUI / DWI / Drunk Driving Lawyers- Experienced, Successful, Affordable

(425) 493-1115