I think this speaks to a significant misunderstanding that most people hold of the way vision actually works.
Most people imagine that vision is a relatively simple process by which our eyes detect and transmit to us the nature of the world. Not so.
Eyes are complex and interesting organs in their own right but fundamentally what they do is relatively simple. They are able to detect and report to the brain certain qualities of the light that hits them. Primarily these are: intensity, direction, and proximity to three points on the frequency spectrum (what we perceive as red, green, and blue). But this data alone is not vision. Vision is a conscious experience our brains create by interpreting and processing this data into the visual field before us—basically, a full scale 3D model of the world in front of us, including the blended information on reflection and emission that color entails.
Quite amazing! Most of this takes place in the human brain, and not the eyes. From this perspective, it is not terribly surprising that an organism with more complex eyes but a much simpler brain might have worse vision than we do.
