Nystagmus is an involuntary movement of the eyes that can be a sign of congenital disorders or central nervous system disorders. It can also be the result of toxicity, pharmaceutical drugs or alcohol.

Performing the Test

  1. Ask the patient to keep their eyes fixed on mobile point or object while keeping their head immobile
  2. Move that point or object briskly from side to side at eye level, stopping abruptly at both the left and right sides
  3. One or two "beats" of the eyes when they abruptly stop is considered normal
  4. Ongoing beats, however, is considered positive for the presence of nystagmus
  5. Extra information can be gleaned by determining the direction of the nystagmus's plane:
    • Horizontal
    • Vertical
    • Torsional (rotary)
    • Mixed
  6. Also not the direction of the slow and quick components


  1. Bickley, Lynn S. Bates' Guide to Physical Examination and History Taking. 8th ed. Philadelphia, PA: Lippincott Williams & Wilkins: 2003.