Every once in a while, a neuroscientist gets obsessed with an optical illusion. What's convenient is that the obsessions tend to lead to new understandings of visual processing.
Alexis Madrigal offers a nice review of the "can't unsee" phenomenon in the piece below. As Bradley Voytek points out, the real takeaway here is that a massive amount of our visual experience is the result of funky cortical feedback loops—not simply the signals coming in from the retina. It turns out that the brain is pretty easy to trick. It's no wonder that optical illusions work as well as they do.
Of course, now I can't unsee the World Cup logo as a facepalm.
To paraphrase all of them: It is not that the real world doesn't exist, but more that we experience it as a hybrid reality: our top-down categories and imagination of the world and our bottom-up sensory experience of the world blend seamlessly into the experience of walking outside into the sunshine or seeing a bird on a wire or eating an oyster or seeing Jesus in a tortilla.