Does too much musturbating cause blur in the eye?

Straining issue: The problem is with straining, and there actually have been documented cases of severe hemorrhages of the macula (central visual part of the retina) associated with "auto-erotic" activity in a man. There was at least a temporary loss of vision with this, although it most likely recovered. Straining, from whatever reason, was the cause of the hemorrhage.

Not really: Masturbating causing vision loss is, for the most part, a myth. Very rarely, sexual activity can cause enough blood pressure elevation (e.g. During orgasm) to cause a hemorrhage in the eye, but in such rare cases, vision loss is usually profound, not just blurring.