The character 睡 depicts a person (目, an eye) with drooping eyelids (垂, to droop), visually capturing the moment of falling asleep. 眠 combines 目 (eye) with 民 (often used here for its sound, but historically implying "closed" or "unseen"), emphasizing the state of having the eyes closed in sleep. Together, they form 睡眠 by layering these two complementary pictographic ideas, one focusing on the act of falling asleep and the other on the state of being asleep, to create a complete concept of "sleep" as both a process and a condition.