Vision or Eyesight?

I may be on a kick of just not knowing very much about anything. Is that something you can turn up or down several notches at will? A coping mechanism maybe?
But, I don't know if it's my vision or my eyesight that sees the distortion I notice when I run my eyes along a high line wire. The spot I focus on gets bent out of shape by the floaters in my eyes. So what I see looks like the U-shaped part of the wire in this picture. But is the problem my vision or my eyesight? Or is it just this heat?