Georgia drivers who search for drunk eyes vs sober eyes usually want one plain answer: how much can a police officer really tell by looking at someone's eyes at the roadside? This page walks through the DUI eye test, the rest of the field sobriety battery, how officers score each exercise, and whether you have to take any of it during a Georgia traffic stop.
How Many Field Sobriety Tests Are There?
Drivers pulled over at a Georgia traffic stop often wonder how many field sobriety tests are required. The short answer is that no specific number is legally required. The roadside exercises are voluntary, and an officer may choose to administer all, some, or none of them.
The National Highway Traffic Safety Administration (NHTSA) recognizes three standardized field sobriety tests, often called the SFST battery:
- Horizontal Gaze Nystagmus (HGN). The officer asks the driver to follow a small light or fingertip with the eyes while keeping the head still. The officer watches for involuntary jerking as the eyes track the stimulus side to side.
- Walk-and-Turn. The driver takes nine heel-to-toe steps along a line, turns in a specific way, and walks back. The officer scores balance, step count, arm position, and whether the driver starts before the instructions end.
- One-Leg Stand. The driver raises one foot off the ground and counts aloud until told to stop. The officer watches for swaying, hopping, putting the foot down, or raising the arms.
Officers may also use non-standardized exercises such as the finger-to-nose touch, alphabet recitation, or Romberg balance test. These lack NHTSA validation research and carry less weight in court. The officer at the scene decides which tests to give based on personal observations, training, and the circumstances of the stop.
Scoring depends entirely on what the officer sees and records. Uneven roadside pavement, passing traffic, weather, footwear, fatigue, age, injury, and medical conditions can all affect performance. None of those factors involve alcohol.
How Officers Score the Walk-and-Turn and One-Leg Stand
The two balance exercises share a design. Each one asks the driver to hold a set of instructions in mind while the body does something unfamiliar. The theory is that alcohol makes it harder to do both at once. So the officer watches for the moment the driver drops one task to manage the other.
The walk-and-turn has two parts. Scoring starts in the first one. While the officer explains the exercise, the driver has to stand with one foot in front of the other and wait. Stepping out of that stance or starting early counts against the driver before a single step is taken.
During the walking part, the officer watches the heel-to-toe contact. The officer also notes the step count, whether the arms come up, and how the turn is made.
The one-leg stand test works the same way. The driver holds one foot off the ground and counts out loud until the officer says to stop. Swaying, hopping, using the arms, or setting the foot down are all recorded as clues.
Neither exercise produces a number that another person can check later. A driver who is heavy, tired, injured, or wearing work boots may look unsteady on a good day. The officer still writes the same words in the report.
What Is the DUI Eye Test (Horizontal Gaze Nystagmus)?
The DUI eye test is officially known as the horizontal gaze nystagmus, or HGN. It is one of three tests in the NHTSA-standardized SFST battery. Georgia officers rely on it heavily to build evidence in DUI investigations.
Nystagmus is an involuntary jerking of the eye. A driver cannot feel it, cannot see it, and cannot control it. Officers treat that fact as the reason the eye test matters. A driver cannot practice past something the body does on its own.
During the roadside test, the officer asks the driver to stand straight and face the officer. The officer then holds up a finger or small penlight. The officer asks the driver to follow the stimulus with the eyes only, without moving the head.
In the video below, a Georgia State Patrol officer shows how to instruct a driver during the DUI eye test. The officer also shows the signs officers look for during the HGN.
Officers look for three clues in each eye. The maximum is six clues across both eyes:
- Lack of smooth pursuit. The eye drifts and jerks instead of tracking the stimulus smoothly from side to side.
- Distinct and sustained nystagmus at maximum deviation. The eye jerks clearly when the driver looks as far to one side as possible and holds that position for several seconds.
- Onset of nystagmus prior to 45 degrees. The jerking begins before the eye reaches roughly a 45-degree angle from center.
How the officer runs the test matters as much as the score. NHTSA procedures set the distance, height, and speed of each pass of the stimulus. A light held too close, too high, or moved too quickly can produce what looks like a clue when none exists. Headlights, patrol car strobes, or passing traffic behind the officer can also pull the driver's eyes and mimic jerking.
One key difference separates HGN from chemical testing. A breath or blood sample creates a record that can be reviewed later. HGN results exist only in the officer's written account of a few seconds of observation. No one can re-examine the driver's eyes months later to verify the report.
When dash or body camera footage captures the stop, it may show where the officer held the stimulus and how fast it moved. The footage gives a defense attorney something concrete to compare against the narrative.
Drunk Eyes vs Sober Eyes: What an Officer Claims to See
Searches for drunk eyes vs sober eyes ask a direct comparison question. Sober eyes generally track a moving object smoothly. Alcohol can suppress the brain's control of eye movement. This may produce the involuntary jerking an officer scores as a clue.
Officers link several visible eye signals to alcohol and write them up as signs of intoxication. Bloodshot or watery eyes, a slow pupil response, and involuntary jerking when the eyes track a moving object are the main ones. Sober eyes usually track smoothly without jerking at moderate angles.
The comparison articles on drunk vs sober eyes usually stop there. They leave out the part that matters most at a traffic stop. The visible eye signs people link to drinking are not proof of drinking on their own.
Red or watery eyes, droopy lids, and a slow pupil response all have ordinary causes. Fatigue, allergies, contact lenses, crying, cigarette smoke, some medications, and a long work shift produce the same appearance. An officer standing at the window at night cannot separate those causes by sight.
Nystagmus has causes unrelated to alcohol as well. Inner-ear conditions, some neurological conditions, and certain prescription medications can cause it. Some people also show normal end-position nystagmus when they look far to one side.
The takeaway is simple. An officer cannot determine blood alcohol levels by looking at someone's eyes. What an officer describes in a report as drunk eyes is an interpretation. A DUI defense attorney may challenge it with the same care applied to any other piece of the state's evidence.
What the Officer's Report Does and Does Not Show
Weeks after a stop, the case often turns on a short written narrative. The report says which exercises the officer gave, which clues the officer counted, and what the officer concluded. It rarely records the things that shaped the result.
Reports often leave out the slope and surface of the road. Reports do not note what the driver was wearing, how cold or wet it was, or where the patrol lights were pointed. Reports also rarely capture whether traffic was passing a few feet away. They do not capture the exact words the officer used to give the instructions.
The standardized scoring assumes those instructions were delivered a particular way. Video can fill some of those gaps.
Dash and body camera footage may show the height and speed of the penlight. The footage shows how much room the driver had and whether the driver looked as unsteady as the report describes. A defense attorney can line the footage up against the narrative line by line.
None of that review changes what happened at the roadside. It changes how much weight the officer's conclusion should carry as evidence.
Do You Have to Take a Field Sobriety Test in Georgia?
In Georgia, roadside field sobriety tests are voluntary. A driver may decline to perform them. Many drivers only think to ask do you have to submit to a field sobriety test after the stop has already ended.
The confusion usually comes from Georgia's implied consent law. That law applies to the state-administered chemical test of breath, blood, or urine that an officer requests after an arrest. It does not apply to the roadside exercises.
Refusing the state-administered chemical test carries separate administrative license consequences. A refusal suspends the Georgia license for a minimum of one year. The state handles that through its own process with its own deadlines.
Several practical points matter here. Officers are not required to volunteer that the roadside tests are optional. Requests often sound like instructions, such as "step out and follow my finger with your eyes." A driver may reasonably believe he or she has no choice.
Declining also does not end the stop. An officer may still arrest based on other observations, including the driving pattern, an odor of alcohol, slurred speech, or statements the driver makes. The state would then have to prove impairment in court under Georgia's DUI statute, which makes driving under the influence of alcohol or drugs a crime. Depending on the circumstances, refusing the roadside tests may simply remove one category of evidence from the case.
Nothing here is advice for a specific stop. Anyone unsure about what he or she must do at a Georgia traffic stop should speak with a DUI defense attorney about the actual facts.
Why Field Sobriety Tests Are Often Unreliable
NHTSA developed the standardized field sobriety tests through controlled research. Even under those ideal research conditions, the tests showed limited accuracy. HGN correctly identified impairment roughly 77 percent of the time. The Walk-and-Turn was accurate about 68 percent of the time. The One-Leg Stand came in at roughly 65 percent.
Those numbers assume the officer follows NHTSA administration protocols exactly. Roadside stops rarely match laboratory conditions. Uneven pavement, gravel shoulders, flashing patrol lights, and headlights from passing traffic affect how a driver performs. Wind, rain, and temperature also matter. A driver's age, weight, physical fitness, injuries, and footwear matter too. Work boots or heels make heel-to-toe walking harder. A knee injury makes the one-leg stand difficult for anyone.
Officers sometimes deviate from NHTSA's strict protocols as well. They may give incomplete instructions or rush through the demonstration. They may hold the HGN stimulus at the wrong distance or move it too quickly. Each deviation gives a defense attorney grounds to question whether the results mean what the officer claims.
The combination of limited baseline accuracy and imperfect roadside conditions is why field sobriety test results are one of the most frequently challenged pieces of evidence in Georgia DUI cases. The tests may suggest impairment, but they do not prove it. The gap between suggestion and proof matters in court.
Talk to a Georgia DUI Defense Attorney About Your Field Sobriety Test
Field sobriety and HGN results often form the core of the state's case after a Georgia DUI arrest. How the officer administered the tests, what the officer recorded, and how the report describes each clue can all be examined closely. Video from the stop can be compared against the written account.
Kohn & Yager LLC handles DUI defense in Atlanta and the surrounding Georgia courts. The firm knows how these stops are charged locally. A free consultation is available to discuss what happened at your stop and what the officer claims to have seen.
A Georgia DUI arrest also starts a license clock. A driver has thirty days from the date of the notice of suspension to send the Department of Driver Services a written hearing request with the filing fee, or the right to that hearing is waived. Depending on the circumstances of your case, grounds may exist to contest the field sobriety evidence.
Contact Kohn & Yager LLC to review your field sobriety test and the rest of the evidence in your case.
Frequently Asked Questions About Field Sobriety Tests in Georgia
What Is a Field Sobriety Test? (Definition and Purpose)
NHTSA training materials define field sobriety test procedures as a set of roadside physical and mental exercises that law enforcement officers use to gauge whether a driver may be impaired by alcohol or drugs. The broader phrase is harder to define: sobriety test can mean any assessment of impairment, including breath and blood tests. Field sobriety test refers specifically to the roadside exercises.
In Georgia, officers commonly administer the three NHTSA-standardized tests: Horizontal Gaze Nystagmus, Walk-and-Turn, and One-Leg Stand.
What Is a Field Sobriety Test Supposed to Measure?
A field sobriety test measures nothing directly. The exercises are designed to divide a driver's attention between physical and mental tasks so the officer can watch for specific errors. The officer scores those errors by eye and reports them as signs of impairment.
What Is the DUI Eye Test Called?
The DUI eye test is called the Horizontal Gaze Nystagmus test, or HGN. It is one of three standardized field sobriety tests in the NHTSA battery. Officers use it to look for involuntary eye jerking as the driver follows a stimulus from side to side.
How Many Field Sobriety Tests Are Required?
No specific number is required, because the roadside battery is voluntary. The standardized battery includes three tests. An officer may give all three or add non-standardized exercises that have no validation behind them.
Do You Have to Submit to a Field Sobriety Test in Georgia?
No. Roadside field sobriety tests are voluntary in Georgia, and a driver may politely decline them. The state-administered chemical test requested after an arrest is a separate matter governed by implied consent law, and refusing that test suspends the license for at least one year. Officers rarely tell drivers that the roadside exercises are optional, and declining does not prevent an arrest based on other observations.
What Is the Difference Between Drunk Eyes and Sober Eyes?
Sober eyes usually follow a moving object smoothly. Alcohol may interfere with that control and produce involuntary jerking. Appearance alone proves little, since fatigue, allergies, contacts, smoke, and medications can create the same red or watery look.
Can Medical Conditions Cause You to Fail the HGN Test?
Yes. Inner-ear disorders, some neurological conditions, traumatic brain injuries, and certain prescription medications can all produce nystagmus that has nothing to do with alcohol. Some people also show natural end-position nystagmus when looking far to one side. An officer performing the HGN test at the roadside cannot tell whether jerking comes from alcohol, a medical condition, or a medication.
Is a Roadside Breath Test the Same as a Field Sobriety Test?
No. The physical exercises and the eye test are one thing. The small handheld breath device some officers carry at the roadside is another, and a breathalyzer measures breath alcohol concentration using a device rather than an officer's eye. Both come before an arrest. The state-administered chemical test that implied consent covers comes after an arrest. It is a separate request with separate consequences.
How Accurate Are Field Sobriety Tests?
NHTSA's own validation studies show limited accuracy even under ideal conditions: HGN is roughly 77 percent accurate, Walk-and-Turn about 68 percent, and One-Leg Stand about 65 percent. Roadside conditions such as uneven pavement, flashing lights, weather, and passing traffic can reduce reliability further. The driver's age, weight, or medical conditions can also reduce reliability. These accuracy limits are a common basis for defense challenges in Georgia DUI cases.
What Happens If the Officer Says I Failed the Test?
No pass or fail score exists to look at. The officer decides that the clues add up to impairment and may arrest on that basis. The officer then reads implied consent and requests the state-administered chemical test. What the officer saw at the roadside becomes one piece of the state's case. It can be examined later.