What is "anisocoria"

Anisocoria \An`i*so*co"ri*a\, n. [NL., fr. Gr. ? + ? pupil.] (Med.) Inequality of the pupils of the eye. [Webster 1913 Suppl.] ||

n. (context medicine English) A condition characterized by an unequal size of the pupils of the eye.

Anisocoria is a condition characterized by an unequal size of the eyes' pupils. Affecting 20% of the population, it can be an entirely harmless condition or a symptom of more serious medical problems.