More on Horizontal Field Nystagmus Testing

I ran across this video from YouTube that actually demonstrates a HGN (horizontal gaze nyustagmus) field sobriety test.  The first minute or so of the video is a discussion about the test, but it then cuts to a video of an actual test.  As noted in our last post, there are many non-alcohol related conditions that can cause nystagmus, and there are numerous defenses to it as well.