<prompt> True about central nystagmus -Changing directionNot suppressed by optic fixationHorizontal or verticalAll of the above  <response>: Ans. is d i.e., All of the aboveNystagmuso Nystagmus is a rhythmic oscillatory movement of the eye.o Nystagmus has the following characteristics:-i Rapid,iiInvoluntary,iii Repetitiveo Nystagmus may be 0 Side to side horizontal nystagmusUp and down verticle nystagmusRotaryo Vestibular nystagmus has two components, i.e. a slow and a fast.o The direction of nystagmus is indicated by the direction of the fast component.o Vestibular nystagmus may be:- Peripheral:-due to a lesion of labyrinth or VIII nerve.Centraldue :-to lesion of vestibular nuclei, brainstem or cerebellum.Peripheral nystagmusDiminishes or suppresses with gaze fixation optic fixationEnhances in darkness or by use of Frenzel glassesUnidirectional fast componentThe direction is typically horizontal - rotary, not purely horizontal or rotary and not verticalThe direction is fixed towards the undermost earPresent in one head positionCentral nystagmusNot suppressed by optic fixationThe fast component can be unidirectional or bidirectional.Can be horizontal, vertical or rotary a Direction is changingPresent in multiple head positions 