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HGN Horizontal Gaze Nystagmus

HGN – Horizontal Gaze Nystagmus

HGN Horizontal Gaze NystagmusA person arrested for drunk driving is typically asked to take an HGN horizontal gaze nystagmus test, or DUI eye test. Every knowledgeable DUI lawyer knows that HGN stands for “horizontal gaze nystagmus.”

Part of the Standardized Field Sobriety Test (SFST) Battery

Under NHTSA (National Highway Traffic and Safety Administration) training, the HGN test is the first roadside evaluation given. The HGN test is an eye test that mimics a medical procedure known as “lateral gaze nystagmus.” This evaluation that only medical and eye doctors use (i.e., registered nurses are NOT trained in saccadic movements and types of nystagmus like a neurologist), was one of three SFSTs that Dr. Marcelline Burns and her study team approved for use by police officers.

Ironically, Dr. Marcelline Burns is NOT qualified (and never has been) to give the HGN evaluation herself! Nor was any member of the Southern California Research team medically trained. Yet they recommended in 1981 that police use the HGN test as part of the field sobriety tests TO ARREST PEOPLE.

See this scathing appellate decision holding that she was not an expert in HGN: State v. Lasworth, 131 N.M. 736, 42 P.3d 844 (Ct. App. 2001). This decision has been adapted by government officials to try to determine which drivers show symptoms of central nervous system depression.

While the HGN test is used by medical professionals, no medical professional uses horizontal gaze nystagmus to determine alcohol levels. The HGN test in the medical field is used to determine neurological injury or lesions in the brain. Because the federal government has the ability to create training materials for law enforcement officers without having such materials peer-reviewed for scientific accuracy, the field sobriety tests used by police officers are NOT “scientific” in terms of being able to produce RELIABLE results, despite the claims of NHTSA.

From a testing and measurement perspective, a RELIABLE “test” is one that consistently yields 90% or better repeatability. College aptitude tests like the SAT or the ACT have this proven “reliability.” Cognitive tests set up for military personnel to be screened for assignment and deployment to the best unit or division (to capitalize on their skills and capabilities) have this level of reliability.

Furthermore, the IQ tests that have been used in clinical psychology and educational psychology for a century also have this 90+ per cent (or better) level of reliability. But, NONE of the standardized field sobriety tests (the HGN, the walk and turn, the one leg stand tests) have this repeatability. The so-called “validation studies” authorized by NHTSA in the 1990s were NOT executed following the scientific method, nor were these bogus reports in any way proven to be reliable or even fair.

Never Take the HGN Horizontal Gaze Nystagmus Test!

Sadly, the VOLUNTARY field sobriety test “false tests” have been allowed in criminal cases to arrest MILLIONS of Americans when there is no scientific reliability to support the HGN test being a reliable means of identifying an impaired driver. Notice the word “voluntary,” meaning that NO DRIVER HAS TO ATTEMPT to do these false tests. Simply say NO to ALL questioning and to all roadside evaluations.

Many people arrested for DUI ask the officer why they are being arrested. One of the most common replies from police officers is that he or she could see that the person’s eyes were not following the stimulus properly. So, drunk eyes is one of the DUI tests given by police officers as part of the field sobriety test battery. This police eye test is not much better than flipping a coin to decide who will be arrested.

Don’t play that game, and let a police officer with a high school education use a medical test — or any field sobriety tests — to decide whether you should be arrested! The HGN horizontal gaze nystagmus test is set up for failure.

For any DUI arrest in Georgia, call William C. “Bubba” Head, a DUI lawyer in Atlanta, for his highly- valued FREE consultation. Our DUI law firm will confidently handle your case, or refer you to top criminal lawyers across GA at other DUI law firms.

Call 1-888-384-4323 [1-888-DUI-HEAD] day or night, or email Mr. Head at his DUI law office at

Further Reading

For more information on field sobriety tests, take a look at one of our articles detailing specific aspects of these DUI tests below: