upturned eyes
For when a character's eyes are pointed upwards relative to their face. This is often done to look cute, coy, childish, timid, submissive, or pleading.
Good examples include post #822731, post #1088527, post #459094, post #1851379, and post #2999790.
This expression is sometimes accompanied by the face tilted downward, sometimes with face facing forward but looking upward, often occurs alongside raised eyebrows. It also occurs when a character is looking at the viewer, but is below their eye-level (such as often the case with fellatio).
This is different from rolling eyes or eyes rolled back in the head (as in ahegao) in that in this case something is actively being focused on and looked at.