Abducens Nerve (CN VI): Function, Anatomy, Symptoms and Care
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer
The abducens nerve, also known as the sixth cranial nerve or CN VI, sends motor signals to the lateral rectus muscle, which moves the eye outward. Damage may cause difficulty moving the eyes left or right, double vision and eye misalignment. See a healthcare provider right away when abducens nerve palsy is suspected [1].
What does the abducens nerve do?
The abducens nerve sends motor signals to the lateral rectus muscle, which moves the eye outward. The left CN VI helps move the left eye left, and the right CN VI helps move the right eye right. [1]
What is another name for the abducens nerve?
The abducens nerve is also known as the sixth cranial nerve or CN VI. [1]
What can happen if the nerve is damaged?
Damage may weaken the lateral rectus muscle. Possible effects include difficulty moving one or both eyes left or right, double vision, eye misalignment, eye strain and eye pain. [1]
Should new symptoms be checked?
Yes. Clinical guidance advises seeing a healthcare provider right away when abducens nerve palsy is suspected, because the cause needs to be determined. [1]
What the research says
Sixth nerve palsy is uncommon, and its cause is often never found. A population-based study of 137 new cases over 15 years found about 11.3 cases per 100,000 people each year; no cause was identified in 26%, while hypertension alone (19%), hypertension with diabetes (12%) and trauma (12%) were the most common associations. (Patel et al., Ophthalmology, 2004) [2]
Diabetes is strongly linked to isolated sixth nerve palsy. In a case-control study of 76 patients and 76 matched controls, diabetes was present in 23.7% of patients versus 5.3% of controls, roughly six-fold higher odds, while high blood pressure alone was not significantly more common. (Patel et al., Ophthalmology, 2005) [3]
Eye-muscle surgery helps most people with lasting palsy. Among 209 patients who had strabismus surgery for abducens nerve palsy, 53.6% reached a good result after one operation and 73.7% after all procedures. (O'Brien et al., J AAPOS, 2023) [4]
What is the abducens nerve?
The abducens nerve is a small motor nerve inside the head. It controls the lateral rectus muscle, an extraocular muscle located outside the eye. The lateral rectus pulls the eye outward: it moves the left eye to the left and the right eye to the right. [1]
Unlike nerves that carry sensory information, the abducens nerve has only a motor function. In practical terms, it carries movement commands from the brain to the muscle that turns the eye outward. [1]
The nerve works as part of a coordinated eye-movement system. It works with the oculomotor nerve, or CN III, and the trochlear nerve, or CN IV, to move the muscles around the eye. The abducens nerve also works with the medial rectus muscle so both eyes can move left and right together. [1]
What does the abducens nerve do in everyday vision?
Every time you look to the side, the abducens nerve helps direct the appropriate lateral rectus muscle to move the eye outward. This allows the left eye to look left and the right eye to look right. [1]
The nerve also contributes to visual awareness of the surrounding environment. For example, when something catches your attention to one side, coordinated eye movement helps you look toward it. The process usually happens without conscious effort. [1]
Because the eyes need to work together, a problem affecting one nerve can interfere with alignment between the eyes. That mismatch can contribute to double vision or other visual discomfort. [1]
Where is the abducens nerve located?
There is one abducens nerve on each side, associated with each eye. The nerve is located behind the eye and follows a long route from the brainstem toward the eye socket. It passes through the subarachnoid space, the dura mater and a canal through the skull before reaching the lateral rectus muscle. [1]
The nerve begins at the brainstem, the part of the brain that connects with the spinal cord, and attaches to a muscle inside the eye socket. It is often described as looking somewhat like a tree branch. [1]
The abducens nerve has one of the longest paths inside the skull of any cranial nerve. Its command center, called the abducens nucleus, is located in the pons. The pons is in the upper back portion of the brain, below the midbrain and above the medulla oblongata. [1]
Structure | Plain-language role |
Abducens nerve / CN VI | Carries motor commands for outward eye movement. |
Lateral rectus muscle | Moves the eye outward, away from the nose. |
Medial rectus muscle | Works with the lateral rectus to coordinate side-to-side eye movement. |
Abducens nucleus | Command center for the abducens nerve, located in the pons. |
Brainstem | Starting region of the nerve’s route toward the eye socket. |
What is abducens nerve palsy?
Abducens nerve palsy, also called sixth nerve palsy, occurs when damage to CN VI weakens the lateral rectus muscle and can lead to muscle paralysis. When the muscle does not receive effective movement messages, the affected eye may not turn outward normally. [1]
Listed causes include diabetes, high blood pressure, head injuries, stroke and many others. These causes are different from one another, so the presence of symptoms does not identify the underlying problem by itself. A healthcare provider should evaluate new symptoms right away. [1]
The nerve’s long route from the back toward the front of the brain may also make it more vulnerable to damage or injury. [1]
What are the symptoms of abducens nerve conditions?
Symptoms can vary depending on which nerve is affected and how much the lateral rectus muscle is weakened. Possible symptoms include difficulty or inability to move one or both eyes to the left or right, double vision, eye misalignment, eye strain and eye pain. [1]
Double vision is also called diplopia. Eye misalignment may make the two eyes point in different directions instead of working together. Eye strain or pain can accompany the effort to maintain comfortable vision. [1]
These symptoms can have more than one possible cause. A symptom list cannot confirm abducens nerve palsy, and an examination is needed to determine what is affecting eye movement. [1]
Symptom guide
Possible symptom | What it may feel or look like |
Difficulty moving an eye | One or both eyes may not move normally to the left or right. |
Double vision | A single object may appear as two images. |
Eye misalignment | The eyes may not point in the same direction. |
Eye strain | Vision may feel uncomfortable or effortful. |
Eye pain | Pain may occur around or with eye movement. |
When should you seek care for new abducens nerve symptoms?
New difficulty moving an eye, double vision, eye misalignment, eye strain or eye pain should be assessed promptly by a healthcare provider or eye care specialist. Clinical guidance specifically advises seeing a healthcare provider right away when abducens nerve palsy is suspected because the cause needs to be determined. Call 911 or go to the emergency room if double vision starts suddenly or comes with a severe headache, weakness, numbness, trouble speaking, drooping eyelid or a head injury, because these can be signs of a stroke, aneurysm or other emergency. [1]
Do not use this article to decide that a symptom is caused by CN VI. The same symptom may occur in more than one setting, and determining the cause requires a clinical assessment. If symptoms begin after a head injury or occur in the context of a condition such as diabetes, high blood pressure or stroke, tell the clinician clearly when the symptoms started and what changed. [1]
How is the abducens nerve evaluated?
A healthcare provider or eye care specialist may assess CN VI with an eye examination, blood tests and imaging tests. The choice of testing depends on the person’s symptoms and the clinician’s assessment of possible causes. [1]
During an eye examination, the provider may check vision and ask the person to move the eyes in different directions. This helps show which eye movements are possible and which may be affected. [1]
Blood tests may be offered to help determine the cause of symptoms. MRI can show the nerves and tissues inside the head and may be used to look at the abducens nerve. [1]
Evaluation step | What it can assess |
Eye examination | Vision and eye movement in different directions. |
Blood tests | Possible clues about the cause of symptoms. |
MRI | Nerves and tissues inside the head. |
Testing is not a self-directed checklist. A clinician decides which examination or test is appropriate after reviewing symptoms and performing an assessment. [1]
How are abducens nerve conditions treated and managed?
Treatment begins after a provider makes a diagnosis and determines the cause. The plan is individualized and can vary from person to person. [1]
Treatment options include managing or treating the underlying condition, wearing an eye patch or corrective lenses, receiving botulinum toxin injections and having surgery. Not every option is appropriate for every person, and this list does not indicate which treatment someone should choose. [1]
The goal of care depends on what is causing the symptoms and how the affected eye movement is changing. A healthcare provider can explain the expected role, benefits and limitations of any recommended treatment. [1]
Care options at a glance
Care category | Examples |
Address the cause | Manage or treat the underlying condition. |
Support vision | Eye patch or corrective lenses. |
Procedure-based options | Botulinum toxin injections or surgery. |
Individual planning | Select care according to the diagnosis and the person’s needs. |
How can you support overall abducens nerve health?
The abducens nerve is part of a broader communication network between the brain and muscles. Clinical guidance connects nerve care with overall health measures, including eating healthy meals, participating in regular physical activity and following a provider’s treatment plan for underlying conditions. [1]
These measures do not diagnose or directly treat an abducens nerve problem. They are general health-supporting actions. Ask a healthcare provider how they apply to your situation, especially if you have symptoms affecting eye movement or vision. [1]
What questions should you ask a healthcare provider about the abducens nerve?
Helpful questions about abducens nerve symptoms include whether double vision could have more than one cause, which eye movements are affected, whether blood tests or imaging are needed and which treatments fit.
Question | Why it may help |
Could my eye movement or double vision have more than one possible cause? | It keeps the discussion focused on evaluation rather than self-diagnosis. |
Which eye movements appear affected? | The examination can clarify the pattern of movement changes. |
Do I need blood tests or imaging? | The provider can explain which tests may help determine the cause. |
What treatment options fit the cause of my symptoms? | Care can vary from person to person. |
How should I protect comfort and vision while being evaluated? | The provider can discuss options such as an eye patch or corrective lenses when appropriate. |
Conclusion
The abducens nerve, or CN VI, is a motor nerve that controls the lateral rectus muscle and helps each eye move outward. It works with other eye-movement muscles and nerves to keep side-to-side gaze coordinated. [1]
When CN VI is affected, symptoms may include reduced eye movement, double vision, eye misalignment, eye strain or eye pain. Because many different conditions can affect the nerve, new symptoms should be assessed right away rather than interpreted from a symptom list alone. [1]
Next step: If you have new or persistent changes in eye movement or double vision, arrange an assessment with a healthcare provider or eye care specialist and bring a clear description of when the symptoms began and how they affect your vision.
FAQ
Is the abducens nerve the same as the sixth cranial nerve?
Yes. The abducens nerve is also called the sixth cranial nerve or CN VI. It has a motor function and controls the lateral rectus muscle. [1]
Which muscle does the abducens nerve control?
The abducens nerve controls the lateral rectus muscle, which moves the eye outward. [1]
Can an abducens nerve problem cause double vision?
Yes. Abducens nerve palsy may cause double vision, along with difficulty moving an eye, eye misalignment, eye strain or eye pain. [1]
What can cause abducens nerve palsy?
Listed causes include diabetes, high blood pressure, head injuries, stroke and many others. A clinician must evaluate the person to determine the cause. [1]
What tests may be used?
An eye examination, blood tests and imaging tests such as MRI may be used to evaluate the nerve and help determine the cause of symptoms. [1]
How is abducens nerve palsy treated?
Treatment depends on the cause and may include managing the underlying condition, an eye patch or corrective lenses, botulinum toxin injections or surgery. The appropriate plan varies from person to person. [1]
Can I care for my abducens nerves?
Clinical guidance recommends caring for overall health through healthy meals, regular physical activity and following a provider’s treatment plan for underlying conditions. Ask a provider for advice about your own health needs. [1]
Should I wait to see if new double vision goes away?
Clinical guidance advises seeing a healthcare provider right away when abducens nerve palsy is suspected. New double vision or difficulty moving an eye should be evaluated rather than self-diagnosed. [1]
Where is the abducens nerve located?
The abducens nerve starts in the pons, part of the brainstem, and travels a long path inside the skull to the lateral rectus muscle of the eye. There is one on each side.
Is abducens nerve palsy an emergency?
It needs prompt medical care to find the cause. Call 911 if double vision starts suddenly with a severe headache, weakness, numbness, trouble speaking, a drooping eyelid or after a head injury.
External Links
Related Reading
Diplopia (Double Vision): What Causes It, How It's Classified, and When It's an Emergency explains the causes of double vision and when it is an emergency.
Oculomotor Nerve (CN III): Anatomy, Function, and Vision Health covers the third cranial nerve that moves most other eye muscles.
Understanding the Trochlear Nerve: The Pulley System of Your Eye describes the fourth cranial nerve and the eye muscle it controls.
Strabismus Surgery: How Eye Muscle Surgery Realigns the Eyes, Recovery and Risks explains eye-muscle surgery used to realign the eyes.
References
Cleveland Clinic. Abducens Nerve: What It Is, Function, Location & Conditions. Cleveland Clinic. Last updated December 4, 2024. https://my.clevelandclinic.org/health/body/abducens-nerve
Patel SV, Mutyala S, Leske DA, et al. Incidence, associations, and evaluation of sixth nerve palsy using a population-based method. Ophthalmology. 2004;111(2):369-375. PMID 15019392. https://doi.org/10.1016/j.ophtha.2003.05.024
Patel SV, Holmes JM, Hodge DO, et al. Diabetes and hypertension in isolated sixth nerve palsy: a population-based study. Ophthalmology. 2005;112(5):760-763. PMID 15878054. https://doi.org/10.1016/j.ophtha.2004.11.057
O'Brien JC, Melson AT, Bryant JC, et al. Surgical outcomes following strabismus surgery for abducens nerve palsy. J AAPOS. 2023;27(3):142.e1-142.e6. PMID 37179001. https://doi.org/10.1016/j.jaapos.2023.04.003
Disclaimer
This article is for educational purposes only and is not a diagnosis or individualized medical advice. Always consult a qualified healthcare provider about your own health, and seek prompt care for new or worsening symptoms.
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