This is really interesting. As someone who's been gradually losing his vision, I've noticed some of this stuff on my own, but it's nice to see a good writeup so

This is really interesting. As someone who's been gradually losing his vision, I've noticed some of this stuff on my own, but it's nice to see a good writeup so one doesn't have to figure out everything from first principles. Just one more thing to add to my bag of tricks.