It's not until Book Three of Paradise Lost that the poet explicitly reveals to us, to his readers, the fact of the physical handicap that might reasonably be thought to render impossible his composition of the poem.

直到失乐园第三卷,诗人才明确告诉读者们，自己失明的事实,这可能被合理的认为是他无法完成诗歌创作的原因。

耶鲁公开课 - 弥尔顿课程节选