expression, ichidan verb
be surprised; be bewildered; be flustered; roll one's eyes
Idiomatic expression describing someone so shocked or flustered that their eyes dart around or they look visibly panicked. The literal image is of eyes rolling between white and black, but it is used figuratively for extreme surprise or confusion.
She was flabbergasted at the sudden news, her eyes darting around in shock.
あまりの難問に、生徒たちは目を白黒させるばかりだった。
Faced with such a difficult problem, the students could only stare in bewilderment.