Eye movement disorders are not a single condition — they are a signal that runs through dozens of neurological diseases, from the most common (Alzheimer's, Parkinson's, concussion) to the most rare. The ClearGazeTest platform reads those signals objectively, at the point of care, in under five minutes.
The oculomotor system is not a peripheral structure — it is a direct extension of the brain's most critical networks. Eye movements are generated and controlled by a distributed circuit spanning the frontal eye fields, superior colliculus, cerebellum, brainstem nuclei, and vestibular pathways. This circuit overlaps precisely with the systems disrupted by the neurological diseases that cause the greatest burden of human suffering.
When any part of this network is damaged — by trauma, neurodegeneration, demyelination, vascular injury, autoimmune attack, or genetic mutation — the disruption shows up in measurable changes to eye movement patterns. This is not a new finding: the oculomotor examination has been a cornerstone of neurological assessment for over a century. What is new is the ability to quantify these findings precisely, repeatedly, and at the point of care.
The diseases listed on this page represent the full clinical spectrum in which oculomotor assessment has established scientific value — from concussion, which affects millions annually and is acutely under-diagnosed, to Alzheimer's disease, where eye tracking changes appear years before cognitive symptoms, to rare genetic and autoimmune conditions where objective monitoring can guide treatment decisions in the absence of other reliable biomarkers.
The ClearGazeTest platform was designed to serve this entire spectrum — integrating oculomotor assessment with ultrasound-based physiological sensing and AI-driven signal analysis into a single wearable point-of-care system.
The structures that generate eye movements — frontal cortex, basal ganglia, cerebellum, brainstem, vestibular nuclei, cranial nerve nuclei — are affected in virtually every major neurological disease. Measuring eye movements is, in effect, measuring the integrity of the entire central nervous system.
Traditional bedside oculomotor examination is qualitative — "nystagmus present," "smooth pursuit degraded." This produces no biomarker value for tracking disease progression, treatment response, or recovery. ClearGazeTest replaces clinical impression with quantitative, reproducible measurements that can be trended over time.
Common diseases justify deployment scale; rare diseases justify the technology. The ClearGazeTest platform provides value across both — objective monitoring where nothing comparable currently exists at the point of care, regardless of disease prevalence.
By combining oculomotor assessment with point-of-care ultrasound (optic nerve sheath diameter, transcranial Doppler), ClearGazeTest captures physiological dimensions that neither modality alone can provide — particularly relevant in conditions involving intracranial pressure, vascular changes, or optic nerve pathology.
Eye movement disorders are not peripheral — they are a core feature of the most common and most burdensome neurological conditions. The following represent the primary clinical domains where ClearGazeTest assessment has established or emerging scientific value.
Oculomotor dysfunction is present in up to 69% of concussion patients and is among the most sensitive objective biomarkers available for mTBI. Smooth pursuit degradation, saccadic abnormalities, vergence insufficiency, and VOR impairment each reflect the distributed neural disruption caused by head trauma — and each is quantifiable at the point of care.
Current standard-of-care tools (SCAT5, ImPACT) rely on subjective symptom reporting and are susceptible to underreporting. Oculomotor assessment provides an objective physiological signal independent of patient cooperation or motivation.
Anti-saccade error rates, fixation instability, and smooth pursuit gain decline have been documented in Mild Cognitive Impairment (MCI) and early Alzheimer's disease — in multiple independent cohorts — years before standard cognitive screening detects decline. These changes reflect degeneration in the frontal eye fields and cortical-subcortical circuits that are among the earliest structures affected in Alzheimer's pathology.
Oculomotor biomarkers offer a low-cost, non-invasive screening and monitoring channel alongside emerging blood-based and imaging biomarkers.
Characteristic oculomotor findings in Parkinson's disease — hypometric saccades, square wave jerks, convergence insufficiency, and impaired VOR suppression — reflect dopaminergic and brainstem pathway degeneration. In atypical Parkinsonisms (PSP, MSA, CBD), oculomotor features are often diagnostically distinctive: vertical supranuclear gaze palsy is a defining feature of Progressive Supranuclear Palsy.
Quantitative oculomotor tracking provides an objective biomarker for disease staging and treatment response monitoring.
Internuclear ophthalmoplegia (INO) — a classic finding in MS — results from demyelination of the medial longitudinal fasciculus and produces characteristic adduction slowing with contralateral nystagmus. Optic neuritis, present in approximately 50% of MS patients at some point in their disease course, also produces quantifiable oculomotor and visual pathway changes detectable before MRI lesion burden changes.
Eye movement monitoring provides an accessible, repeatable biomarker for relapse detection and treatment response in a disease defined by its episodic course.
Ocular motor nerve palsies (CN III, IV, VI), gaze palsies, nystagmus, and diplopia are common acute presentations of stroke, reflecting lesion localization across the brainstem and cortex. Posterior circulation strokes — involving the cerebellum, brainstem, and occipital lobe — produce characteristic oculomotor patterns that distinguish them from anterior circulation events.
Accurate, rapid bedside oculomotor assessment has direct implications for triage, localization, and treatment decisions in acute stroke settings.
Vestibular disorders — including benign paroxysmal positional vertigo (BPPV), vestibular neuritis, labyrinthitis, and Menière's disease — produce characteristic nystagmus patterns that are both diagnostically informative and objectively measurable. The video head impulse test (vHIT), which quantifies the vestibulo-ocular reflex, has become a standard diagnostic tool in vestibular evaluation and is directly within the measurement scope of ClearGazeTest.
Accurate differentiation of central versus peripheral vertigo has immediate clinical urgency, as central causes may indicate stroke or posterior fossa lesion.
Tumors affecting the optic chiasm — most commonly pituitary adenomas — produce characteristic bitemporal hemianopsia and visual field loss that can be quantified through oculomotor scanning behavior. Posterior fossa and brainstem tumors produce gaze palsies, nystagmus, and cranial nerve findings that are directly accessible through eye movement assessment.
Chiasm disorders impair depth perception, reading, and visual navigation — the patient may not perceive approaching vehicles and may lose the ability to drive safely. Serial oculomotor monitoring supports treatment response evaluation and functional assessment.
Migraine with aura produces visual, sensory, and motor symptoms — including scotoma, fortification spectra, and transient oculomotor disturbances — that are directly measurable during and between attacks. Interictally, subtle oculomotor changes in smooth pursuit and saccadic performance have been documented in migraineurs, reflecting persistent cortical excitability changes.
Ophthalmoplegic migraine — a rare variant — produces recurrent ocular motor nerve palsies that may be confused with other serious etiologies and require objective assessment for differentiation.
Systemic lupus erythematosus (SLE), neuromyelitis optica spectrum disorder (NMOSD), sarcoidosis, and giant cell arteritis can each affect the visual and oculomotor pathways. Giant cell arteritis — an inflammation of medium and large arteries from the neck into the head — can cause sudden, irreversible vision loss in one eye and requires urgent assessment; ultrasound plays a key diagnostic role in evaluating temporal artery involvement.
NMOSD specifically targets the optic nerves and spinal cord, producing severe optic neuritis as a primary manifestation and representing an important differential from MS.
Damage to the optic nerve and visual pathways represents a distinct and clinically significant category of neuro-visual disease — ranging from common inflammatory conditions to vision-threatening emergencies. Point-of-care ultrasound and quantitative visual assessment are directly applicable across this spectrum.
Optic neuropathies encompass a spectrum of conditions causing damage to the optic nerve, resulting in pain — classically worsened with eye movement — and vision loss most commonly affecting the central visual field (scotoma). The optic nerve is accessible to both ultrasound assessment (optic nerve sheath diameter provides an indirect measure of intracranial pressure) and to quantitative visual pathway testing through pupillary light reflex analysis and contrast sensitivity measurement.
Causes include ischemia, compression, inflammation, toxic-metabolic injury, and hereditary conditions. Distinguishing the etiology has direct treatment implications and urgency.
👁️ Relevant biomarkers: ONSD · Pupillary reflex velocity · Contrast sensitivityOptic neuritis — inflammation of the optic nerve — results from infections, immune-mediated disorders (lupus, NMOSD), or occurs as the presenting event of multiple sclerosis. The critical clinical significance: approximately 50% of patients who develop optic neuritis will develop MS within 15 years. Early, objective documentation of visual pathway dysfunction supports timely MRI risk stratification and consideration of disease-modifying therapy before MS establishes itself.
Most cases resolve within a year, but quantitative tracking of recovery trajectory — afferent pupillary defect, visual acuity, contrast sensitivity — provides objective monitoring that subjective complaint scales cannot.
⚠️ MS risk marker — up to 50% conversion at 15 yearsGiant cell arteritis is a medical emergency with respect to vision: ischemic optic neuropathy causing sudden, permanent vision loss can be the presenting event, and the risk of the second eye being affected within days to weeks is high without prompt corticosteroid treatment. The disease involves inflammation of medium and large arteries extending from the neck through the head.
Crucially, ultrasound is a primary diagnostic tool in GCA — the "halo sign" on temporal artery ultrasound is a validated diagnostic finding, making this condition a direct use case for ClearGazeTest's integrated ultrasound capability alongside oculomotor and visual pathway assessment.
🔊 Ultrasound diagnostic: temporal artery halo signThe optic chiasm — where the nasal fibers from each eye cross to the contralateral hemisphere — is vulnerable to compression from pituitary tumors, craniopharyngiomas, and vascular lesions. The signature field defect is bitemporal hemianopsia: loss of the outer half of each eye's visual field, producing a characteristic visual scanning pattern detectable through oculomotor assessment.
The functional consequences are substantial: impaired depth perception, inability to detect approaching hazards from the periphery, and loss of the ability to drive safely. Serial monitoring is essential in patients with known pituitary tumors or after surgical decompression, where objective field recovery documentation supports clinical decision-making about driving and daily activities.
📊 Functional assessment: scanning behavior · Visual navigationEye movement disorders — abnormalities of the muscles, nerves, and brain circuits that control gaze — are a direct readout of underlying neurological pathology. Each disorder type has a characteristic neural substrate, and quantitative assessment allows localization and monitoring that subjective examination cannot reliably provide.
Involuntary repetitive eye oscillations with multiple subtypes — each with distinct neural localizing value. Peripheral nystagmus (vestibular origin) is horizontal, direction-fixed, suppressed by visual fixation, and typically benign. Central nystagmus (brainstem/cerebellar) may be direction-changing, purely vertical or torsional, not suppressed by fixation, and indicates serious pathology.
Double vision results from misalignment of the visual axes, typically due to cranial nerve palsies (CN III, IV, VI) or neuromuscular junction disease (myasthenia gravis). New-onset diplopia in an adult is a neurological emergency until structural, vascular, or compressive etiologies are excluded. Quantitative measurement of ocular alignment and duction range supports triage and localization.
The perception that stationary objects are moving or oscillating, resulting from nystagmus or abnormal VOR function. Oscillopsia is profoundly disabling — it impairs reading, walking, driving, and daily function — yet it is entirely invisible to the examiner without objective measurement. Bilateral vestibular loss (from aminoglycosides, meningitis, or autoimmune disease) produces Dandy's syndrome: oscillopsia on head movement that quantitative vHIT can document precisely.
Saccades — rapid eye movements that redirect gaze — are generated by a precisely timed brainstem burst-pause neuron circuit modulated by the cerebellum and frontal cortex. Hypometric saccades (undershooting) indicate cerebellar or basal ganglia pathology; hypermetric saccades (overshooting) suggest cerebellar disease; slow saccades are characteristic of progressive supranuclear palsy, spinocerebellar ataxia, and Huntington's disease. Saccadic latency changes are among the earliest detectable biomarkers in Alzheimer's disease.
Smooth pursuit — the system that keeps a moving target on the fovea — requires intact frontal and parietal cortex, cerebellum, and brainstem. Gain reduction (the eye lagging behind the target) and intrusive saccades during pursuit are sensitive biomarkers across a broad range of neurological conditions, including concussion, MS, Parkinson's disease, schizophrenia, and frontotemporal dementia. Smooth pursuit is one of the most widely studied oculomotor biomarkers in neuroscience.
Vergence — the ability to converge and diverge the eyes for near and far targets — depends on intact midbrain circuits and is reliably disrupted by concussion (convergence insufficiency), Parkinson's disease, PSP, and dorsal midbrain lesions. Convergence insufficiency following concussion is one of the most common and most functionally disabling post-concussive visual complaints, directly measurable through near-point convergence testing.
These eye movement findings should prompt urgent evaluation — they can indicate stroke, aneurysm, tumor, or other serious neurological emergencies. Objective documentation accelerates appropriate triage.
Eye movement disorders occur across the full spectrum of neurological disease — including many rare and ultra-rare conditions where objective oculomotor monitoring may be the only available non-invasive biomarker for disease progression and treatment response.
One integrated wearable platform. Across the full spectrum of neurological disease. No specialist required.
No — and it is not designed to. ClearGazeTest provides a quantitative, objective oculomotor and physiological assessment that supplements and enhances the clinical examination. It replaces the subjective, impression-based oculomotor component of bedside evaluation with precise measurements. Clinical diagnosis remains the physician's responsibility. What ClearGazeTest provides is objective data that makes that diagnosis better informed.
Yes. The same integrated hardware platform — wearable headset with oculomotor sensors and ultrasound — is used across all indications. The AI software layer applies disease-relevant biomarker analysis depending on the clinical context. This is analogous to how an ECG machine is the same hardware whether you are screening for atrial fibrillation, ischemia, or heart block — the biomarker interpretation varies by indication, but the sensing platform is shared.
Certain conditions — giant cell arteritis, optic neuritis, intracranial hypertension, vascular disease — have specific diagnostic or monitoring value in ultrasound data that oculomotor assessment alone cannot provide. Optic nerve sheath diameter (ONSD) measured via ultrasound is a validated surrogate for elevated intracranial pressure. Temporal artery ultrasound is a primary diagnostic tool in GCA. By integrating both modalities, ClearGazeTest provides a more complete physiological picture — particularly relevant in the acute and emergency settings where critical decisions must be made rapidly.
Rare diseases are often where objective monitoring is most urgently needed and least available. When a disease affects a small population, subjective clinical scales — which have high variability — make it very difficult to demonstrate treatment effects in clinical trials. Quantitative oculomotor biomarkers can serve as sensitive, reproducible clinical trial endpoints in rare neurodegenerative diseases, which is why rare disease drug developers are increasingly interested in this measurement category. The ClearGazeTest platform is relevant across prevalence — from the 39 million Americans with migraine to diseases affecting a few thousand patients nationwide.
It means assessment at the location of the patient — a sports sideline, emergency department, primary care clinic, neurology office, assisted living facility, or research site — without requiring transport to a specialized laboratory, a specialist appointment wait, or expensive imaging equipment. For acute conditions like concussion and giant cell arteritis, point-of-care assessment has direct time-sensitive clinical value. For chronic and progressive conditions like Alzheimer's and Parkinson's, it enables frequent serial monitoring that laboratory-based systems cannot practically support.
Whether you are a clinician, researcher, health system, or pharmaceutical partner — we want to understand your specific disease context and assessment needs.