Seeing the world through quantum eyes has changed the view of the universe around me in strange ways. Density is an all important fundamental in differentiating one particle from another. Same goes for the macro condition of things on Earth. We only learned how to fly when we realized that the air, like water is a substance that we all swim through. Wood, leaves, and brick are only modestly denser than air but that slim difference gives our world structure inside a gravity field.
Imagine if your eyes could only see density, no color, nothing impenetrable, just variations on dense. I suppose that's a lot of what we do because of shapes but we can't tell with our eyes what is more dense. Starting with air, we'd see a fog. Through that to a chair back that had shape but translucent, then to a more transparent, but not invisible window, more air, some leaves, the grass, the earth and all the variations in between. The world would turn into an uncolored, layered line drawn illustration. Much like some of the translucent creatures at the bottom of the deep ocean.
What if there are already creatures living this way, using density as their relative medium? Like clouds they might float on the surface of our atmosphere, or the depths of the ocean. We might not have sensitivity to detect them because they are only subtly denser or less dense than their surroundings. The very Ozone! Perhaps they are as large as the void between planets because their density is so slight.
Just a thought to steer the landlocked into imagining that possibilities of life need not start and end with us.