2002 NHTSA PHASE I & PHASE II remain rather unchanged. Phase III HGN

NHTSA changed the definition of nystagmus to “an involuntary jerking of the eyes[1].” Apparently, NHTSA got tired of the officer’s saying everyone has a nystagmus even when not consuming alcohol.

NHTSA no longer tells officers not to administer HGN to people with eye problems or that medical conditions that will affect the test.

Further, no more reference to PAN I and PAN II, describing when alcohol may be increasing or decreasing. However, the old manuals never informed the officer on how to determine PAN I or PAN II anyway.

HGN – Scoring and standardizes clues: No noticeable changes. VGN

The present definition of VGN is used: “Vertical Gaze Nystagmus occurs as the eyes gaze upward. The presence of this type of nystagmus is associated with high doses of alcohol for that individual and certain other drugs. The drugs that cause Vertical Gaze Nystagmus are the same ones that cause Horizontal Gaze Nystagmus.[2] Walk and Turn

No noticeable changes. One Leg Stand

No noticeable changes.

[1]Id at VII-5

[2]Id at VIII-4

[3] Hereafter referenced as NHTSA 2004

[4]Id at VIII-3