I’ve recently realised that I have this to a large degree. If I shut my eyes and try to picture an apple (or anything else), I tend to see something vague and blurry which disappears or fades if I try to focus on it. Sometimes a more vivid image flashes into my mind, but it’s as though I see it out of the corner of my eye and then it’s gone again!
I’m wondering how common this is. How clearly can you see things in your mind’s eye?