Have fun with strabismus!

Waveforms

A recording of the eye movements from someone who has no nystagmus, will essentially show a straight line.
Eye movements of nystagmus patients show there are different waveforms for different types of nystagmus. The different forms have inspired the names that have been given to the various forms; in general they tend to look like sine waves in congenital nystagmus ("pendular nystagmus"), and when they have a with a slow phase, as in latent nystagmus, followed by a rapid return, they resemble sawtooth waves ("jerk nystagmus").
Examples of eye movement recordings of someone viewing a stationary object during 2 seconds:

Normal person:


Someone who has congenital nystagmus; 'pendular' movements are seen, of equal speed, amplitude, and duration in each direction, like sine waves:


Latent nystagmus shows 'saw-tooth'-like waves:

The movements of the two eyes are usually conjugate, so you'll see the movements of the other eye 'mirrored', as in the next picture:



The frequency is, roughly, usually about 4 Hz.
_{Note: None of the above are actual recordings, they are drawings to illustrate the idea.}