Optokinetic Nystagmus occurs under which condition?

Optokinetic Nystagmus occurs when the eyes track a moving object. This reflexive eye movement helps in stabilizing images on the retina during movement, allowing for a clearer vision of the moving stimuli. When an individual watches something moving across their field of view, such as a car passing by or stripes on a rotating drum, their eyes will automatically follow the object. If the object moves too quickly or out of the visual field, the eyes will exhibit a quick movement back to the original position to reacquire the target, creating a pattern of rhythmic eye movements characteristic of nystagmus. Hence, the condition described in the correct answer is one where the eyes focus on a moving object, showcasing how the visual system responds to motion.