Gaze induced nystagmus occurs or is exacerbated as a result of changing ones gaze toward or away from a particular side which has an affected central apparatus. Peripheral nystagmus occurs as a result of either normal or diseased functional states of the vestibular system and may combine a rotational component with vertical or horizontal eye movements and may be spontaneous, positional, or evoked. Positional nystagmus occurs when a persons head is in a specific position. An example of disease state in which this occurs is Benign paroxysmal positional vertigo (BPPV). Post rotational nystagmus occurs after an imbalance is created between a normal side and a diseased side by stimulation of the vestibular system by rapid shaking or rotation of the head. Spontaneous nystagmus is nystagmus that occurs randomly, regardless of the position of the patients head. Physiological nystagmus
Physiological nystagmus is a form of involuntary eye movement that is part of the vestibulo-ocular reflex (VOR), characterized by alternating smooth pursuit in one direction and saccadic movement in the other direction. Variations
The direction of nystagmus is defined by the direction of its quick phase (e.g. a right-beating nystagmus is characterized by a rightward-moving quick phase, and a left-beating nystagmus by a leftward-moving quick phase). The oscillations may occur in the vertical, horizontal or torsional planes, or in any combination. The resulting nystagmus is often named as a gross description of the movement, e.g. downbeat nystagmus, upbeat nystagmus, seesaw nystagmus, periodic alternating nystagmus.
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 nystagmus
Early-onset nystagmus occurs more frequently than acquired nystagmus. It can be insular or accompany other disorders (such as micro-ophthalmic anomalies or Down syndrome). Early-onset nystagmus 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 nystagmus include the following, along with some of their causes:

Infantile:
Albinism
Aniridia
Bilateral congenital cataract
Bilateral optic nerve hypoplasia
Idiopathic
Lebers congenital amaurosis
Optic nerve or macular disease
Persistent tunica vasculosa lentis
Rod monochromatism
Visual-motor syndrome of functional monophthalmus
Latent nystagmus
Noonan syndrome
Nystagmus blockage syndromeX-linked infantile nystagmus is associated with mutations of the gene FRMD7, which is located on the X chromosome.Infantile nystagmus 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 NYX (nyctalopin). CSNB-2 involves mutations of CACNA1F, a voltage-gated calcium channel that, when mutated, does not conduct ions. Acquired nystagmus
Nystagmus that occurs later in childhood or in adulthood is called acquired nystagmus. The cause is often unknown, or idiopathic, and thus referred to as idiopathic nystagmus.