Humans all see the world differently and I don't just mean that we hold different worldviews. There must be incredible variability in the way human vision functions. Physical eyesight is such an important evolutionary adaptation, requiring so many different genes for development and function that variability is a no-brainer. Think of all the sight defects that you already know - color-blindness, myopia (not reading-induced), astigmatism to name a few. Then imagine for a moment all the variability that goes unconsidered after image acquisition. Color, for example, is a qualia the source of which is a puzzle with no answer (qualia are subjective properties of human consciousness). Before you suggest that color is simply a function of wavelength, re-read Newton and read over the work of Edwin Land. Some savants claim to sense visual manifestations of abstract numbers or ideas (see this article - I've read other similar stories). Without going too far afield or taking too much away from a future topic of The Golden Sieve, let us just say that our assumptions regarding the universality of our visual perception are not solid. Understanding how the mind's eye works is the key to understanding how to use images successfully, in my opinion.
These are the things I think about when creating photographs, especially one like this - a color photograph of a black and white world. Lake Michigan (between Fullerton and North Beach) and the Near-North skyline, January 2010.