Kevin's point about not always relying on our eyes is a good one.
I'm probably not alone in obsessively running what I'm working on through my head when I'm away from any version of the text I can see. Often, getting back to the text shows me a line, a stanza, a paragraph I'd "forgotten." These tend to be fruitful cuts.
I'm also intrigued by John's desire to see the words he's working with. The approaches, of course, don't have to be mutually exclusive (though we have to choose one at a time).