Can nystagmus be caused by conversion disorder?

Unlikely: Nystagmus is most commonly the result of inner ear injury. Viral infection could be the cause. Also, nystagmus is almost always accompanied by true vertigo. Although inner disease is most common, the vestibular system of the brain stem can also be the source of nystagmus. I have not heard of conversion disorder causing movement of the eye ball unless that disorder involves the above structures.

OptokineticNystagmus: can help the doctor differentiate complaints related to physical causes from those that are conversion symptoms. This is to confirming that from a physiologic standpoint, the visual pathways are intact.