Cute, but it's not about "spirits." From a Christian perspective, spiritual blindness is about not being able to see / believe in Christ, and that means not being able to see God. It's also about not seeing that this world, all of existence, is more than just physical / material. You are more than just a bag of bones and flesh.
And it's starting to get funny how many times I've quoted C.S Lewis on this thread, but that reminds me of one more quote...
"Humans are amphibians - half spirit and half animal. As spirits they belong to the eternal world, but as animals they inhabit time."
Again, even when Jesus walked this earth, there were people who saw Him and the things he did, and did not believe. That was spiritual blindness then, and that same blindness exists today.