eyes in shadow
When the eyes of someone or something can be seen while the surrounding area is in total darkness. Think "glowing eyes peering out of a cave" level of darkness.
Often goes along with face in shadow. Why dis ninja look so mad (meme) is a notable example.
Not to be confused with no eyes or shaded face, where the eyes aren't peering out of total darkness, or void face, where the character's face is always in shadow by design.
Examples
Non-examples
