[BoardsOfCanada]

I think that sounds normal. The mind's eye is more like evoking the sense of seeing something without actually seeing it.

[SamPatt]

This seems like a major point of confusion on the subject.

I agree with your interpretation, but there are those charts which show varying degrees of clarity of mental images (using an apple), I don't understand how to square that with just invoking the sense instead of actually seeing it.