Driving under the influence of drugs is an increasing focus for law enforcement across the United States. In Utah, police officers investigating suspected drug impairment sometimes use a roadside eye test known as Loss of Convergence (LOC).
The Loss of Convergence DUI Utah test is commonly used during drug-related DUI investigations, but it is important to understand that this test is not one of the standardized field sobriety tests recognized by the National Highway Traffic Safety Administration (NHTSA).
Understanding how the test works—and how it can potentially be challenged—can play a critical role in a Utah DUI defense case.
What Is the Loss of Convergence Test?
The Loss of Convergence test is an eye coordination test used by police officers to help detect possible drug impairment.
The test evaluates whether a person’s eyes can properly converge inward (cross toward each other) while focusing on an object that moves toward the bridge of the nose.
Normally, both eyes should move inward together to maintain focus on a nearby object. Certain drugs may interfere with the muscles responsible for this coordinated eye movement.
If one eye drifts outward or fails to cross properly, an officer may interpret that observation as a “loss of convergence.”
However, it is important to understand that this test is only one observation among many during a DUI investigation and does not prove impairment by itself.
Non-Standardized Field Sobriety Tests Used in Utah
In addition to standardized field sobriety tests, officers in Utah often use several non-standardized roadside tests during DUI investigations.
These tests are not part of the official testing battery approved by NHTSA and do not have the same level of scientific validation.
Common non-standardized tests used in Utah DUI investigations include:
- Modified Romberg Balance Test
- Loss of Convergence Eye Test
- Finger-to-Nose Test
Some officers receive training in these procedures through programs such as:
- ARIDE (Advanced Roadside Impaired Driving Enforcement)
- Drug Recognition Expert (DRE) training
However, not every officer performing these tests has completed these specialized programs.
Because these tests are less standardized, their reliability and interpretation may be challenged in court.
Standardized Field Sobriety Tests in Utah DUI Cases
Utah law enforcement officers are typically trained to administer three standardized field sobriety tests recognized by NHTSA.
These tests are considered the primary roadside tools used during DUI investigations.
The Three Standardized Field Sobriety Tests
- Horizontal Gaze Nystagmus (HGN) Observes involuntary jerking of the eyes.
- Walk-and-Turn Test Evaluates balance and the ability to follow instructions.
- One-Leg Stand Test Measures balance and divided attention.
These tests follow specific standardized procedures, and officers are trained to administer them according to strict guidelines.
If these tests are administered incorrectly, the results may be challenged during a DUI case.
How the Loss of Convergence Test Is Performed
During a DUI investigation, the officer may perform the Loss of Convergence DUI Utah test using a pen, penlight, or similar object.
The test is conducted in several steps.
1. Initial Instructions
The officer instructs the driver to:
- Keep their head still
- Follow the object using only their eyes
- Attempt to keep both eyes focused on the stimulus as it moves toward their nose
The officer typically explains that the object will not touch the nose.
2. Establishing the Starting Position
The officer holds a small object approximately 12–15 inches from the driver’s face.
The object may briefly move in a small circular motion above eye level to confirm that the person can see and track the stimulus.
3. Moving the Stimulus Toward the Nose
Once tracking ability is confirmed, the officer slowly moves the stimulus toward the bridge of the nose.
The object is usually brought to approximately two inches from the nose and briefly held in that position.
4. Observing the Eyes
The officer carefully watches the eyes to determine whether both eyes properly converge inward.
Normal Result
- Both eyes cross inward
- The subject maintains focus on the stimulus
Loss of Convergence
- One eye drifts outward
- The subject cannot maintain focus on the stimulus
5. Repeating the Test
To confirm the observation:
- The officer should perform the test at least twice
- If the results differ, a third test may be performed
Repeating the test helps determine whether the observation is consistent or unreliable.
Drugs Associated With Loss of Convergence
According to ARIDE and Drug Recognition Expert training, certain drug categories may be associated with loss of convergence.
These may include:
- Central Nervous System (CNS) depressants
- Dissociative anesthetics (such as PCP or ketamine)
- Inhalants
- Cannabis (marijuana)
These substances can affect the muscles and neurological pathways responsible for coordinated eye movement.
However, many medical or environmental factors can also influence eye behavior, which is why this test is not considered definitive proof of impairment.
Loss of Convergence Is Only One Observation
It is important to understand that Loss of Convergence is not proof of drug impairment.
Like other roadside tests, it is simply one factor an officer may rely on when determining whether probable cause exists to make a DUI arrest.
Drivers should also know that:
Field sobriety tests are voluntary in Utah.
This includes:
- Standardized field sobriety tests
- Non-standardized tests such as the Loss of Convergence test
These roadside exercises are designed to give officers additional observations during a DUI investigation, but they are not mandatory.
Challenging Loss of Convergence Evidence in Court
In many DUI cases, the officer’s observations during roadside testing become part of the probable cause used to justify an arrest.
However, the reliability of the Loss of Convergence test may be challenged under several circumstances.
Common legal challenges may arise when:
- The officer failed to follow proper procedures
- The officer lacked training in the test
- The test was administered incorrectly
- Lighting, weather, or environmental factors interfered
- Medical conditions affected eye movement
Because the test is non-standardized, courts may scrutinize how it was performed and whether the officer’s conclusions were reliable.
If field sobriety tests are administered improperly, a defense attorney may file a motion to suppress evidence or challenge probable cause for the arrest.
In some situations, this can lead to reduced charges or dismissal of a DUI case.
Speak With a Utah DUI Lawyer
If you have been arrested for DUI in Utah, it is important to carefully review how roadside tests were administered and whether proper procedures were followed.
A DUI defense attorney can analyze:
- Dash camera footage
- Body camera recordings
- Field sobriety testing procedures
- Officer training and qualifications
Identifying errors in the investigation may help build a strong defense strategy.
For a confidential consultation regarding a Utah DUI case:
Call or Text Jake Gunter
📞 (801) 373-6345