Nystagmus

So the patient generates a second saccade, and third etc., which also drift back.

If the patient looks to the left the same thing happens.

This rhythmic eye movement is called nystagmus.

Nystagmus consists of a quick phase (saccades) and a slow phase (in this case a drift back to center)

This particular form of nystagmus is called gaze paretic nystagmus because

• the drift is exponential
• the drift direction is different depending on where the patient looks.