So what did happen?
Let’s say the Patagonians could see from mirror to mirror to mirror all the way to their library.
Now let’s say that the laws of physics are more like habits of nature. It almost doesn’t matter what they are, so long as they’re consistent when they meet. So long as humanity was separated by the Atlantic, it’s possible for the old world – Europe – to have one set of physics and its own diffraction limit, and the New World to have a subtly different set of physics and no diffraction limit at all.
So when de Isla went to visit Patagonia he saw the world through their eyes. He was using the local physics. His vividness wasn’t induced by illness or peyote at all, but he really could see without blurring.