If the colored part of your eye (the drain plug) suddenly creeps into the entire drainage system of your eye and gets stuck in there and doesn't come out on its own, the fluid in your eye will have nowhere to go. The fluid in the eye will accumulate very rapidly.
Typically one will experience pain, a red eye, colored haloes, headache, blurry vision, and even nausea. Most of the vision can be lost in a matter of hours or few days. The ability to see colors and shades of black and white rarely return to normal.
Treatment is to place a hole through the colored part of the eye as an emergency. Most of the time this can be accomplished with the aforementioned laser. However, due to the swelling to the eye, it can be very difficult to accomplish. Rarely, surgery may need to be performed urgently to create a new drainage system for the eye.