THE VEHICLE WAS STATIONARY IN A PUBLIC PARKING LOT. AS THE REAR POWER LIFT GATE WAS COMING DOWN TO CLOSE, I QUICKLY REACHED IN TO PUSH A TARP OUT OF THE WAY...THE LIFT GATE CAME DOWN ON TOP OF MY HEAD AND DID NOT AUTO REVERSE. IT CONTINUED DOWNWARD AFTER STRIKING MY HEAD SENDING ME TO THE GROUND. THIS BLUNT FORCE TRAUMA TO MY HEAD RESULTED IN PERMANENT VISION LOSS TO THE MACULA OF MY LEFT EYE CALLED A SCOTOMA (IS/OS DEFECT.)