What is the term for involuntary eye movements that oscillate side-to-side or up and down?

The term for involuntary eye movements that oscillate side-to-side or up and down is nystagmus. This condition is characterized by a rhythmic back-and-forth movement of the eyes, which can be caused by a variety of factors including neurological disorders, vestibular system issues, or even congenital conditions.

Nystagmus can present in different forms, such as horizontal, vertical, or rotational, and may be present at rest or only during certain activities. The key feature of nystagmus is the involuntary nature of the eye movements, distinguishing it from other eye conditions.

Understanding other terms in the context helps clarify why they do not describe these specific eye movements. Amblyopia refers to a developmental condition resulting in decreased vision in one or both eyes, typically caused by a lack of visual stimulation during early childhood. Strabismus involves a misalignment of the eyes, where one eye may point in a different direction than the other, affecting binocular vision. Photophobia is a sensitivity to light, which results in discomfort or pain in bright environments and is unrelated to involuntary eye movements.

Therefore, nystagmus is the appropriate term that specifically describes the involuntary eye movements noted in the question.