Which of the following is a correct description of nystagmus?

Nystagmus is characterized by involuntary eye movements, which can manifest as rapid side-to-side oscillations, up-and-down movements, or a combination of both. These eye movements can occur when the eyes try to fixate on a stationary object but cannot maintain the position due to various factors, such as vestibular disorders or neurological issues. The condition can affect balance and visual stability, but the fundamental description of nystagmus itself specifically involves these involuntary movements of the eyes. This is what makes the first option the correct and precise description of nystagmus.