Shadow’s Vision

Shadow describes itself as achromatic rather than monochrome; this is, as discussed in the notes on that chapter, an accurate distinction. I kept it brief there, but thought I’d go into more detail separately. I think people often conflate the two terms, in part because humans cannot have monochrome vision. Or, well, maybe; it’s hard to say whether what someone sees is grey or they’re subjectively seeing everything as a single color. Because monochrome means exactly that, that only shades of a single general color are going to be in use in an image. It gets used to refer to black and white but that’s not quite right; monochrome would be more that, say, all of the parts of the image are different hues of red.

But human eyes have three cone varieties and are measuring relative activity of each to establish what color something is. This is why there are three primary colors in art, not anything about the colors themselves; red, yellow, and blue do not have any special quality. But the three cone varieties in the eye respond at different intensity to different wavelengths of light. Because of this, you get effectively as many combinations as there are ways to assign priority. Each cone being prompted will push the image further towards the subjective experience of that color. If there’s only one cone type, there’s no contrast of relative intensity, and thus the brain can’t assign different colors. It’s hard to say whether this produces black-and-white or the brain makes a single color image, since describing the subjective experience of a color is basically impossible. But it can be confidently said that color cannot be seen separately from brightness without multiple cone varieties involved.

However, Shadow is achromatic. It lacks color entirely, not even of a single shade. This is something more akin to a different form of color blindness. If there are no cones at all, then the eye has to rely upon rods, and we know that visual condition doesn’t see color because rods don’t provide color information to begin with. Cones, being high-acuity and color-sensitive, are what would usually be seeing that, while rods are providing peripheral vision and low-light vision. Removing cones entirely means that there is no input to the parts of the brain that would ordinarily be producing color vision. This type of color blindness is associated with other, debilitating visual conditions, but one of the traits will be a total absence of color. This is both what Shadow looks like and how it sees. Its vision is not going to suffer from this in the same ways; in a material sense, what this would be like is replacing all of the cones with rods, and then elevating the sensitivity and acuity of the rods in a preternatural way. It’s exaggerated because magic; rods have better night vision than cones, but Shadow doesn’t need any light at all. But in a biology sense, this is a useful way to distinguish how it sees from how most people would see.