1.
pupil
The dark circular opening in the center of the iris.
瞳 literally means the pupil of the eye, but is often used poetically to mean "eyes" in general.
Usage
1. 瞳孔 (pupil) - the technical meaning
2. Eyes - especially in literary or emotional contexts
Common expressions
Register
瞳 has a more literary, poetic, or romantic nuance compared to the everyday word 目.
Name
Common Japanese female name (瞳).