I am like you. I’m guessing that the author needed to use the stuff seen by his eyes while closed as a springboard to seeing something with his mind’s eye.

My dad told me about monk’s who meditate on imagining that their thoughts exist behind their belly button. As you noted, your mind’s eye is not located in the same physical space as your actual eyes. Similarly, there is no reason the thoughts you hear couldn’t be happening in your belly button.

But I’ve found it remarkably difficult to convince my mind that it exist anywhere other than my head. I don’t think this difficulty is based on biology. I think it’s just conditioning. But damn, it’s hard.