More blind spots

Wild. It not only matches background colors, but completes the line across the blindspot too. I wonder what happens if the line enters the blindspot but doesn't come out the other side? (Try it yourself. Make the spot disappear and then bring a pencil in from the side so the tip is just into the spot). And how about if there are things that don't get interrupted by the blindspot at all? Can they affect what the brain makes up to put there?

I need to think about this. Can I go back to the beginning please?