Carp, as prey fish rather than predators, have their eyes positioned on the sides of their heads, giving them maximum wide-angle vision.
This enables them to spot danger more effectively, but this means they have to rely more on their other senses when feeding.
Carp do have colour vision, but because water absorbs different colours of light at different rates they tend to be able to see better at the blue end of the spectrum than we do, and can even see into the ultra violet spectrum. Better blue vision works well at night, meaning carp can see well after dark.
However, in murky water sight is not the primary sense of carp – instead they rely on their lateral line and barbules to find food.