Mine is a shimmering rainbow zigzag shape that starts as a point and expands into a halo with the center open to my normal vision until it goes out of my field

Mine is a shimmering rainbow zigzag shape that starts as a point and expands into a halo with the center open to my normal vision until it goes out of my field of vision. Then the headache starts. A dark room and sleep helps me get through it. Hasn't happened much, maybe 4 times in my life.