Oh squiggly line!

Oh squiggly line in my eye fluid. I see you lurking there on the peripheral 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 are forgiven.

Family Guy

These squiggly lines are known as floaters.They are small semi solid fragments of your vitreous humour.

You can smart about it here at Wikipedia: Floater Article

Just a random fact