What does anisocoria refer to?

Anisocoria specifically refers to a condition where there is a difference in the size of the two pupils. This can occur due to various underlying causes, including neurological impairment, anatomical defects, or certain medications. The key aspect of anisocoria is that it highlights an inequality in pupil size, which can be an important clinical sign that prompts further investigation into conditions affecting the nervous system or eye health.

The other choices do not accurately reflect the definition of anisocoria. Widening of the pupil describes a different phenomenon called mydriasis, while narrowing of the pupil relates to miosis. Rhythmic movement of the eye does not pertain to pupil size but could describe a condition such as nystagmus. Understanding these distinctions is crucial in clinical assessments related to ocular health.