Standard Field Sobriety Tests -- Horizontal Gaze Nystagmus.
We have demonstrated previously the tests that are used by police. These are called the Standard Field Sobriety Tests. Click here to see a clip of each test that is administered by the police. In a series of blogs, we will discuss and evaluate each of the tests that are administered by the police.
First, let us examine the Horizontal Gaze Nystagmus. This test has routinely been held admissible in all courts in Texas. Nystagmus is a clunky, scientific term that is sued to describe the movement associated with a person's eyes. Generally, this movement is described as bouncing. HGN is a type of jerk or bouncing movement of the eyes in the direction of the gaze. The purpose of the jerking of the eyes is best illuminated when juxtaposed with normal eye movement. The eye normally moves smoothly like a marble moving over a glass surface.
HGN is an involuntary motion and the subject of the test will not know that his or her eye is bouncing because the jerking or bouncing does not affect vision. Generally speaking, nystagmus can occur because of a disturbance of the inner ear. Alcohol consumption, however, can cause it, as well.
Stay tuned as we evaluate the affects of alcohol on nystagmus, in the
DWI context. If you have been charged with a DWI,
contact a
Plano DWI lawyer today.