https://www.youtube.com/watch?v=Xzk_7Q5orwU&feature=plcp Call Mark Thiessen The Texas Trial Attorney at: 713-864-9000<br />Thiessen Law Firm<br />1221 Studewood St.<br />Houston, TX 77008<br />Visit my youtube page for more helpful DWI tips.<br /><br />The horizontal gaze nystagmus (HGN) is the pen test you see the officers doing in someones face. What they are looking for is a small jerking of your eye or a nystagmus due to a central nervous system depressant like alcohol being introduced into your system. They're looking for six clues total three in each eye. Wach the video to find out more about the horizontal gaze nystagmus.
