October 29, 2015

DWI Detection and Standardized Field Sobriety Testing Horizontal Gaze Nystagmus Test Demonstration

Session 8 - Concepts and Principles of the Standardized Field Sobriety Tests (SFST)
DWI Detection and Standardized Field Sobriety Testing
Horizontal Gaze Nystagmus
Test Demonstration
8-61
Test Demonstration
Session 8 - Concepts and Principles of the Standardized Field Sobriety Tests (SFST)
DWI Detection and Standardized Field Sobriety Testing
Check for eyeglasses
Verbal instructions
Position stimulus (12-15 inches and slightly above
eye level)
Check for equal pupil size and resting nystagmus
Check for equal tracking
Administrative Procedures
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Session 8 - Concepts and Principles of the Standardized Field Sobriety Tests (SFST)
DWI Detection and Standardized Field Sobriety Testing
Lack of smooth pursuit
Distinct and sustained nystagmus as maximum
deviation
Onset of nystagmus prior to 45 degrees
Total the clues
Check for vertical nystagmus
Administrative Procedures (Cont.)
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HS 178 R5/13 39 of 62
Session 8 - Concepts and Principles of the Standardized Field Sobriety Tests (SFST)
DWI Detection and Standardized Field Sobriety Testing
Vertical Gaze Nystagmus
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D. Vertical Gaze Nystagmus
The Vertical Gaze Nystagmus test is simple to administer. During the Vertical Gaze
Nystagmus test, look for jerking as the eyes move up and are held for a minimum of
four seconds at maximum elevation.
• Position the stimulus horizontally, about 12 - 15 inches in front of the subject's nose.
• Instruct the subject to hold the head still, and follow the object with the eyes only.
• Raise the object until the subject's eyes are elevated as far as possible.
• Hold for a minimum of four seconds.
• Watch closely for evidence of the eyes jerking upward.
Session 8 - Concepts and Principles of the Standardized Field Sobriety Tests (SFST)
DWI Detection and Standardized Field Sobriety Testing
Vertical Gaze Nystagmus
8-65
Participant led demonstration.
For VGN to be recorded, it must be distinct and sustained for a minimum of four
seconds at maximum elevation.
VGN may be present in subjects under the influence of high doses of alcohol for that
individual, and some other drugs.
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HS 178 R5/13 40 of 62 Source: DWI Detection and
Standardized Field
Sobriety Testing
March 2013 Edition

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