The cause of pathological<unk>  may be congenital, idiopathic, or secondary to a pre-existing neurological disorder. It also may be induced temporarily by disorientation (such as on roller coaster rides or when a person has been spinning in circles) or by some drugs (alcohol, lidocaine, and other central nervous system depressants, inhalant drugs, stimulants, psychedelics, and dissociative drugs). Early-onset<unk>  Example of congenital (early onset)<unk>  Early-onset<unk>  occurs more frequently than acquired<unk> . It can be insular or accompany other disorders (such as micro-ophthalmic anomalies or Down syndrome). Early-onset<unk>  itself is usually mild and non-progressive. The affected persons are usually unaware of their spontaneous eye movements, but vision can be impaired depending on the severity of the eye movements. Types of early-onset<unk>  include the following, along with some of their causes: *Infantile: *Albinism *Aniridia *Bilateral congenital cataract *Bilateral optic nerve hypoplasia *Idiopathic *Leber's congenital amaurosis *Optic nerve or macular disease *Persistent tunica vasculosa lentis *Rod monochromatism *Visual-motor syndrome of functional monophthalmus *Latent<unk>  *Noonan syndrome<unk>  blockage syndrome X-linked infantile<unk>  is associated with mutations of the gene FRMD7, which is located on the X chromosome. Infantile<unk>  is also associated with two X-linked eye diseases known as complete congenital stationary night blindness (CSNB) and incomplete CSNB (iCSNB or CSNB-2), which are caused by mutations of one of two genes located on the X chromosome. In CSNB, mutations are found in<unk> X <unk> ctalopin). CSNB-2 involves mutations of CACNA1F, a voltage-gated calcium channel that, when mutated, does not conduct ions. Acquired<unk> <unk>  that occurs later in childhood or in adulthood is called acquired<unk> . The cause is often unknown, or idiopathic, and thus referred to as idiopathic<unk> . Other common causes include diseases and disorders of the central nervous system, metabolic disorders and alcohol and drug toxicity. In the elderly, stroke is the most common cause. General diseases and conditions Some of the diseases that present<unk>  as a pathological sign or symptom are as follows: :* Aniridia :* Benign paroxysmal positional vertigo :* Brain tumors (medulloblastoma, astrocytoma, or other tumors in the posterior fossa.) :* Canavan disease :* COVID-19 :* Head trauma :* Lateral medullary syndrome :* Ménière's disease and other balance disorders :* Multiple sclerosis :* Optic nerve hypoplasia :* Pelizaeus–Merzbacher disease :* Superior canal dehiscence syndrome :* Tullio phenomenon :* Whipple's disease Toxicity or intoxication, metabolic disorders and combination Sources of toxicity that could lead to<unk> : :* Alcohol intoxication :* Amphetamines :* Barbiturates :* Benzodiazepines :* Ketamine :* Pregabalin :* Lithium :* MDMA :* Nitrous Oxide :* Phencyclidine (PCP) :* Phenytoin (Dilantin) :* Salicylates :* Selective serotonin reuptake inhibitors (SSRIs) :* Other anticonvulsants or sedatives :* Thiamine deficiency :**Wernicke's encephalopathy :**Wernicke–Korsakoff syndrome Thiamine deficiency Risk factors for thiamine deficiency, or beri beri, in turn include a diet of mostly white rice, as well as alcoholism, dialysis, chronic diarrhea, and taking high doses of diuretics. Rarely it may be due to a genetic condition that results in difficulties absorbing thiamine found in food. Wernicke encephalopathy and Korsakoff syndrome are forms of dry beriberi. Central nervous system (CNS) diseases and disorders Central nervous system disorders such as with a cerebellar problem, the<unk>  can be in any direction including horizontal. Purely vertical<unk>  usually originates in the central nervous system, but it is also an adverse effect commonly seen in high phenytoin toxicity. Other causes of toxicity that may result in<unk>  include: :*Brain abscess (Cerebellar) :*Cerebellar ataxia :*Chiari Malformation :*Multiple sclerosis :*Stroke :*Thalamic hemorrhage :*Trauma :*Tumor Other causes :*Non-physiological :*Trochlear nerve malfunction :*Vestibular Pathology (Ménière's disease, SCDS (superior canal dehiscence syndrome), BPPV, Labyrinthitis) :*Exposure to strong magnetic fields (as in MRI machines) :*Long-term lack of light, called miner's<unk>  after 19th-century coal miners who developed<unk>  from working in the dark. :*A slightly different form of<unk>  may be produced voluntarily by some people.
Nystagmus
Ocular tremor
Oscillopsia
Mydriasis
Pendular nystagmus
Ocular dysmetria
Horizontal gaze palsy
Ophthalmoparesis