Different levels of resolution and at different rates; some people are better at it than others. I have been 'blessed' with this ability in maximum totality since birth, and can process much more quickly than what is before me, and do so with eyes open. My internal dialogue is *far* more rich than the world that I live in. I always thought that others were on my level until about 10 years ago; which explains my confused impression of everyone throughout my life. I believe that this ability can be harnessed and cultivated the same as one would by working out, but to convince someone that an upper limit of their mind is far below their capacity is impossible to do because they cannot see it with their eyes like they can with muscle. Look into meditation if you wish to *expand your horizons*. There are images of conversations floating around and studies done to approximate what percentage, and it is shocking really, but nothing definitive that I can point to. >What do they see though? Is it really nothing, perhaps the term "see" is not accurate? I can visualize, simulating the nerves coming in from my eyes. I can be given a description and form a mental picture, which doesn't involve sight. It's not seen literally, but mentally. If they cannot already visualize within the mind, it's an impossible thing to explain. Best example is like day-dreaming, but that which is controlled.