It is not what you look at that matters it is what you see. 翻译为:重要的不是你看什么,而是你看到什么.
这是一个分裂句结构,即俗称的强调句结构,it is ... that. 句子原本是这样的: What you look at does not matter, but what you see matters. 再问: 原句是不是可以拆分成两个强调句:“It is not what you look at that matters; it is what you see that matters.” ? 再答: 是的,就是这样拆分。