October 01, 2018
What is the “eye test” officers do during a DUI traffic stop?
The HGN is an abbreviation for “Horizontal Gaze Nystagmus Test.” HGN is one of several tests, referred to as Standard Field Sobriety Tests (“SFSTs”) that officers perform on an individual that they believe is driving while impaired on alcohol or drugs.
Of the several SFSTs that some officers are trained to conduct, you may be surprised to learn that the HGN is the only “SFST” that is proven to have scientific backing – although there is also science that questions its accuracy as well. The National Highway Traffic Safety Administration indicates that the HGN is 88 percent accurate in determining if an individual has a blood alcohol content (“BAC”) over .08, the legal limit for non-commercial drivers in Georgia.
When an officer is performing an HGN test on a suspected impaired driver, the officer is looking for “nystagmus” in the driver’s eyes. Nystagmus is an involuntary jerking of the eyes, which can be indicative of consumption of and impairment from alcohol and/or certain drugs.
However, it is important to remember that certain medical conditions can also cause nystagmus even when someone has not consumed any alcohol, drugs, or prescription medications. This is why if you are pulled over by an office and asked by the officer to perform SFSTs, you should inform the officer of any and all medical conditions you might have, as certain medical conditions can cause a “false positive” while the officer is performing the test. It is also important to note that the certain illicit drugs and prescription medications may cause impairment, but not show nystagmus.
It is also worth noting that you do not have to perform the HGN or any of the SFSTs just because an officer asks you to do so. You can politely decline, and the officer will continue conducting his or her investigation as he or she sees fit.
It is also important to note that an officer must be properly trained in administering HGN tests. If the test is not performed properly, the results may lead to a false positive. If you have been charged with DUI, you should hire an attorney experienced in DUI law who knows how the HGN test is supposed to be administered and who can challenge the results of an HGN test performed by an untrained or underqualified police officer.
If you have been charged with DUI, call the attorneys at the DeWoskin Law Firm, and make sure you are protected by experienced, knowledgeable attorneys.