A proverb meaning the eyes can say as much as (or more than) the mouth — eye expressions often reveal true feelings.
彼女は一言も話さなかったが、その目は口ほどに物を言っていた。
She didn't say a word, but her eyes said a lot.
面接では話す内容だけでなく、目は口ほどに物を言うかどうかも見られる。
In interviews, not only what you say but whether your eyes speak as much as your words is observed.
子どもの不安そうな目を見て、母親はすぐに気づいた。目は口ほどに物を言うからだ。
Seeing the child's anxious eyes, the mother noticed immediately — the eyes speak as much as words.