What is nystagmus?

Nystagmus is characterized by a rhythmic and involuntary movement of the eyes, which may appear as a back-and-forth motion or as a circular pattern. This condition can occur due to various reasons, including neurological issues, vestibular problems, or even as a side effect of certain medications. It is significant in medical assessments because it can help identify underlying health issues related to the brain or the inner ear. Understanding nystagmus is crucial for tactical medics, as it may indicate head injuries or other neurological conditions that require immediate attention and management in a combat or deployed environment.

The other options refer to different visual or physiological symptoms that do not describe the specific eye movements associated with nystagmus, thus highlighting the distinct nature of this condition.