"Your eyes can deceive you, don't trust them." -Obiwan Kenobi
Once again, I quote Star Wars.
Remember a lot of people who are blind have better senses like hearing, etc. But the best example would be bats using echo location to fly and see where they are going. The same is true for slogs, paramites, and scrabs. They probably have much better attuned hearing and smelling possibilites rather than using eyes or having them.