Imagination and Visualisation

Hello! I hope this is the best place for this topic! So I have this thing that has been bugging me for a while. Whenever I try to imagine something, it's like I'm thinking in facts rather than images. I simply cant "see" what I imagine. If i think of my dad, I think like "a tall person and the color of his hair etc." How is fantisizing for you guys and what can I do to imagine picture'ish? Whenever I ask my friends to imagine per say a cube on the table, they say they actually SEE the cube with 50% transparency. Although when I dream, it's not that way. Sry for long sentences, I hope you understand what I mean!

My understanding is that if you try visualize while awake your eyes still input information into the brain meaning that your brain is already preoccupied and can only overlay an image upon the one it is getting, often this feels as if you are not actually seeing it through your eyes, escpecially in a day dream for example. In a dream however you are no longer recieving sensory input meaning that the brains whole attention is focused on visualization.
With practise you actually get better at visualizing with your eyes open, it's just that nobody ever really tries it.

Thing is, i cant visualize with closed eyes either (awake). Is there a way I can train this up? Daydreaming is hard for me and when I daydream, it's more like im "thinking a scenario" if u know what I mean.. Facts only

I think this might help, it helped me with visualization.
http://www.dreamviews.com/f32/advanc...utorial-80879/

Thanks dutchraptor for explaining it to me ;) And thanks JosephGrimm for that tutorial!