I think she fell victim to a different form of blindness, a blindness that we all live with all of the time. We are convinced that we see a world full of well-defined, well-understood objects. Here is my computer mouse, there is the paper, the coffee mug, and my lava lamp (really) – all visible in the scene in front of my eyes. What we do not appreciate is that all of these objects may be visible but they are not recognized and understood simultaneously. Your ability to recognize objects is limited to one or a very few at one time. If you could recognize everything at the same time, you might, for instance, be able to read this article and another one at the same time. You can't, even if you make the letters large enough. You can recognize many objects per second – about 20-40 per second for simple objects – but at any given moment, you are only updating your information about one or two of these. The rest of what you “see” is a construction, built up out of what you attended to recently and by some reasonable guesses about the way the world works.
… First, there was the blindness caused by unsuccessful deployment of attention. Second, there was a blindness to the first sort of blindness. Both of these are completely normal aspects of everyday life. We can function with these impairments because, most of the time, the world does not violate our theory. Objects obey the rules. If, while I was not attending, my coffee mug chose to hover six inches above the desk, I might well be unaware of it. Since this does not happen (I assume), I can function with only intermittent updates on its status.