Origin

The character 瞳 combines the radical for "eye" on the left with 童, which means "child" or "young person" on the right. The pupil of the eye was poetically called the "child of the eye" in Chinese, because when you look into someone's eye, you can see a tiny reflection of yourself that resembles a small child or doll. By joining these two components together—eye plus child—the character captures this metaphorical image and came to mean the pupil specifically.