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Hashemi Eye Care - Neuroscience Institute and Research Center

Nystagmus (Finding)

Involuntary, rhythmic eye movements that can be observed during examination. Can be normal or indicate vestibular, neurological, or eye conditions.

Nystagmus is an involuntary, rhythmic oscillation of the eyes. When observed during examination, it provides important diagnostic information about the visual and neurological systems.

Key Takeaways

  • Rhythmic, involuntary eye movements
  • May be normal (physiologic) or pathologic
  • Pattern helps identify cause
  • Can indicate inner ear, brain, or eye problems
  • Detailed description important for diagnosis

Describing Nystagmus

Direction

  • Horizontal: Side-to-side
  • Vertical: Up and down
  • Torsional: Rotational
  • Mixed: Combination

Waveform

  • Jerk: Slow drift in one direction, fast correction
  • Pendular: Equal speed both directions

Named Direction

For jerk nystagmus, named by the fast phase:

  • "Right-beating nystagmus" = fast phase to the right

Types of Nystagmus

Physiologic Nystagmus

Normal responses:

  • Optokinetic: Watching repeated moving objects
  • End-point: At extreme lateral gaze (few beats)
  • Vestibulo-ocular: During head rotation

Pathologic Nystagmus

Indicates underlying condition—see Nystagmus (Condition) for detailed information.

Peripheral vestibular (inner ear):

  • Mixed horizontal-torsional
  • Unidirectional (same direction all gaze positions)
  • Suppressed by visual fixation
  • Associated with vertigo

Central (brain):

  • May be any direction
  • May change direction with gaze
  • Not suppressed by fixation
  • May have other neurological signs

Congenital/Infantile:

  • Present from early life
  • Typically horizontal
  • May have null point (position of least nystagmus)

Key Observations

Gaze-Evoked Nystagmus

  • Appears when looking to the side
  • May indicate cerebellar or brainstem problem
  • Or medication effect

Downbeat Nystagmus

  • Fast phase downward
  • Suggests craniocervical junction abnormality
  • Chiari malformation, for example

Upbeat Nystagmus

  • Fast phase upward
  • Brainstem or cerebellar lesion

Periodic Alternating

  • Direction reverses periodically
  • Usually central cause

See-Saw Nystagmus

  • One eye rises and intorts, other falls and extorts
  • Then reverses
  • Suggests parasellar lesion

Clinical Assessment

History Questions

  • When did it start?
  • Constant or intermittent?
  • Associated symptoms (vertigo, hearing loss)?
  • Medications?

Examination

  • Observe in primary gaze
  • Check all directions of gaze
  • Look with and without fixation (Frenzel goggles)
  • Head impulse test
  • Other neurological examination

When Nystagmus Is Concerning

Features suggesting serious cause:

  • New onset in adults
  • Vertical nystagmus
  • Direction-changing nystagmus
  • Associated neurological symptoms
  • Not suppressed by fixation
  • Associated with headache or vomiting

Further Evaluation

Depending on clinical picture:

For comprehensive information on nystagmus as a condition, including causes, treatment, and living with nystagmus, see Nystagmus.

Medically Reviewed Content

This article meets our editorial standards

Written by:
Hashemi Eye Care Medical Team
Medically reviewed by:
Board-Certified Neuro-Ophthalmologist (MD, Neuro-Ophthalmology)
Last reviewed:
January 30, 2025
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