I Have Developed An Arc In My Eye Sight Which

I have developed an arc in my eye sight which flashes to the righ edge when I move my eyes in all directions. This is in addition to a spot in the center of my vision which I used to get only when I had a migraine. During the onset of my migraines, it starts small and colorful and grows to cover my entire sight. Now, the spot is permanent although small, and the arc about halfway around my right eye but not in my direct vision.