I have 5 distinct experiences of vision. They are each qualitatively very different.

• Seeing - When my eyes are open, I see the world around me. I believe this is the standard sense "vision".
• Static - When my eyes are closed, my visual field is mostly colored static, not very bright. Like static on old TVs, but definitely colored.
• Eddies and Afterimage - I can create extremely limited pictures out of Static, nothing more complex than the union of a few very simple shapes. Blobs or occasionally lines.
• Mental Imagery - Bright images as distinct as Seeing, but fleeting and not directly caused by photons.
• Imagination - No visual change, but I "know" what the object looks like or how it is moving. If my coffee mug were to grow legs and walk away, aside from the visual phenomena I would know I was seeing my coffee mug growing legs and walking away and that that was really happening. Imagination is just the middle - the knowing what I am seeing, without any of the visual phenomena or the really-happening sense.

When my eyes are open, Static is still present, but in most cases my brain edits it out and reports only Seeing. When I am looking at a solid color or just paying careful attention it is clear Static is still present. I did not realize this before making an effort to investigate what I am actually Seeing.

Until I read Yvain's Generalizing from One Example post I believed that what I'm calling Imagination is what everyone did when they said they were visualizing. I only have Mental Imagery rarely: sometimes when on the boundary of sleeping and waking or after minutes of effort during meditation. These images are distinct and lasting enough to, say, read about half a line of text from a Mental Image of a page of a book. My memories of the experience of Mental Imagery and of the experience of images seen while dreaming seem to feel the same. I have not been able to focus on these long enough to tell if they have background Static, as paying much attention to them leads directly to their disappearance and the realization that I am now seeing Static and Eddies while looking at the back of my eyelids.