The word 眼睛 is formed by combining two characters, 眼 and 睛, both semantically centered on the concept of the eye. 眼 broadly refers to the eye as an organ or the eye socket, while 睛 specifically denotes the eyeball or pupil. Their fusion creates a compound that comprehensively represents the organ of sight, following a common Chinese pattern where related terms are paired to reinforce or specify meaning, resulting in a unified word for "eyes" in modern usage.