One of the safety rules I enforce in my house are to always use two hands on a bungee cord. If they slip out of your hand they can snap around and hook you in the eye.
Actually, the more common scenario is for the wire hook on the end opposite you to straighten out because of the pressure pulling on it. It then becomes a pointy-tipped projectile traveling directly toward the other end of the cord where the pull is coming from.
An acquaintance was securing a load with a bungee and just this thing happened. He lost an eye.
Not a good outcome.