目めが冴さえる

expression, ichidan verb

be wide-awake; be unable to sleep

Describes a state where one's eyes are clear and alert, often due to excitement, worry, or caffeine, making sleep difficult.

• コーヒーを飲のんだせいで、夜よるになっても目めが冴さえて眠ねむれなかった。

  Because I drank coffee, my eyes were wide awake even at night and I couldn't sleep.

• 明日あしたの発はっ表ぴょうが気きになって、目めが冴さえてしまった。

  Worried about tomorrow's presentation, I ended up wide awake.