Squiggly line

Oh, squiggly line in my eye fluid. I see you lurking there on the periphery of my vision. But when I try to look at you, you scurry away. Are you shy, squiggly line? Why only when I ignore you, do you return to the center of my eye? Oh, squiggly line, it's alright, you're forgiven. - Stewie Griffin

I like the squiggly line...I don't know what they are called, though.