Crossing down from the A to the D

Leaves me blind when I’m playing a scale, because the stupid bow is right in the way of what I’m trying to see.

And for some reason, it doesn’t happen when I’m playing a piece of music. I can cross down there with no problems. With a scale? I can’t see a thing. No, I don’t understand it either, but I’d better if I want to crack this. I’m obviously doing something different when I’m doing scales, and I need to figure out what.