Disconjugate gaze is a condition where the two eyes fail to move together in a coordinated way, causing them to point in slightly or significantly different directions. Normally, both eyes lock onto the same target simultaneously, which is what gives you depth perception and a single, clear image. When that coordination breaks down, the result is typically double vision, blurred vision, or a sense that the world is unstable.
How Normal Eye Coordination Works
Your eyes are controlled by six small muscles each, directed by three cranial nerves. The third cranial nerve (oculomotor) handles most of the eye’s movement range plus eyelid position and pupil size. The fourth (trochlear) controls a single muscle that rotates the eye downward and inward. The sixth (abducens) controls the muscle that pulls the eye outward. These three nerve systems are linked together by a bundle of nerve fibers running through the brainstem called the medial longitudinal fasciculus, or MLF. The MLF is essentially a communication cable that ensures when one eye moves left, the other moves left by the same amount at the same speed.
On top of this basic wiring, higher brain regions coordinate different types of eye movement. Fast scanning movements (saccades) are generated by burst neurons in the pons and midbrain. Smooth tracking movements follow a moving object. The vestibulo-ocular reflex keeps your vision stable when your head turns quickly. All of these systems must work together for the eyes to stay aligned. A problem anywhere along this chain, from the muscles themselves to the brainstem pathways to higher brain centers, can produce disconjugate gaze.
What It Feels Like
The most common symptom is double vision. When each eye points at a slightly different spot, the brain receives two overlapping images. If the misalignment is small, this can register as blurriness rather than obvious doubling. Many people also experience oscillopsia, a sensation that the visual world is bouncing or jumping. This is particularly disorienting during walking or head movement.
The effects often extend beyond vision. Dizziness, vertigo, and difficulty with balance are common because the brain relies heavily on eye position signals to maintain equilibrium. Some people develop a head tilt or turn, angling toward the unaffected side to reduce the double vision. Coordination problems, unsteady walking, and even nausea can follow, especially when the underlying cause involves the brainstem or cerebellum.
Common Causes
Disconjugate gaze is not a disease in itself. It is a sign that something has disrupted the neural pathways or muscles controlling eye movement. The list of possible causes is broad, but a few stand out as the most frequent.
Stroke is one of the leading causes, particularly strokes affecting the pons or midbrain. A stroke in the pons can wipe out horizontal gaze on the same side as the damage, while midbrain strokes tend to impair vertical gaze, making it difficult or impossible to look up or down. A specific pattern called Parinaud syndrome, where upward gaze is lost, can result from a tumor pressing on the midbrain or from a midbrain stroke.
Multiple sclerosis is a common cause in younger adults. It frequently damages the MLF, producing a distinctive pattern called internuclear ophthalmoplegia. In this condition, the affected eye cannot turn inward properly during side-to-side gaze, though it still turns inward normally when focusing on a close object. When MS is the cause, both sides are often affected. In older adults, the same pattern is more likely from a stroke and usually affects only one side.
Traumatic brain injury and concussion can also produce disconjugate eye movements. The delicate brainstem pathways that coordinate the eyes are vulnerable to the shearing forces of head trauma. Other causes include brain tumors, infections like Lyme disease or neurosyphilis, metabolic conditions such as Wernicke encephalopathy (from severe vitamin B1 deficiency), diabetes-related nerve damage, hydrocephalus, and certain drug intoxications including some antidepressants and opioids.
How It Differs From Childhood Strabismus
About 3 to 4 percent of children have chronically misaligned eyes, a condition called strabismus. While the end result looks similar (eyes pointing in different directions), the underlying situation is quite different. Childhood strabismus develops during a sensitive period of brain development when the visual system is still wiring itself. The brain often adapts by suppressing the image from one eye, which prevents double vision but can lead to permanent changes in how the visual and motor systems work together, including abnormal patterns of eye tracking and absent depth perception.
Acquired disconjugate gaze in adults, by contrast, hits a visual system that was previously working normally. The brain has no built-in suppression mechanism, so double vision is usually immediate and obvious. This distinction matters for treatment: childhood strabismus involves retraining a developing brain, while adult-onset disconjugate gaze focuses on treating the underlying neurological cause and managing symptoms.
How It Is Diagnosed
A clinical eye movement exam is the starting point. The examiner asks you to follow a target through nine directions of gaze (the “H-test”), watching for any direction where one eye lags or fails to move fully. After that, the ability to hold a steady gaze is tested. You may be asked to stare at a fixed point for a couple of minutes while the examiner watches for drifting or involuntary oscillation (nystagmus).
Each functional class of eye movement is tested separately: fast scanning movements, smooth tracking, the reflex that stabilizes vision during head turns, and the ability to converge both eyes on a near target. The pattern of which movements are affected and which are spared narrows down where in the brain the problem lies. For example, if one eye fails to turn inward during side gaze but converges normally on a close object, the lesion is almost certainly in the MLF rather than the nerve or muscle itself.
Imaging, typically MRI of the brain, follows the clinical exam to identify the structural cause, whether that is a stroke, demyelinating plaque, tumor, or other lesion.
Treatment and Recovery
Treatment depends heavily on the underlying cause. In the early stages, many eye movement disorders are monitored to see whether they improve on their own, since some resolve as the brain heals from a stroke or as inflammation from MS settles. During this waiting period, practical options keep daily life manageable. Patching one eye eliminates double vision immediately, though it sacrifices depth perception. Prism lenses built into glasses can bend light to realign the two images without surgery. Environmental modifications, like adjusting lighting or using magnification for reading, can also help.
Rehabilitative approaches include convergence training, pursuit training, and saccade training, all aimed at strengthening or retraining specific eye movement systems. Compensatory strategies, such as learning to use head turns to substitute for limited eye movement, or practicing adapted reading techniques, can improve function even when the eye movement disorder itself doesn’t fully resolve.
When misalignment persists and stabilizes, more definitive interventions become options. Botulinum toxin injections into overactive eye muscles can temporarily correct alignment, with effects lasting about three months. This can serve as a bridge or a test run before considering surgery. Surgical realignment of the eye muscles has a high success rate: one study found surgical correction resolved horizontal misalignment in about 93 percent of adults after six months, compared to roughly 51 percent of those treated with botulinum toxin alone.
Recovery timelines vary widely. Some stroke-related eye movement problems improve substantially within weeks. Others take months. Studies tracking gaze abnormalities after stroke have followed patients for two weeks to six months, with outcomes ranging from full recovery to permanent limitation. Younger patients and those with smaller, more localized lesions generally do better. The specific pattern of disconjugate gaze also matters: isolated cranial nerve palsies tend to recover more completely than damage to central brainstem pathways.