I get those a couple times a year. Mine are sinus migrane related. Advil migrane and rest in darkness/silence. Goes away in about an hour. Then I'm tired but ok.I get "painless" migraines. I get the aura (exactly like the below pic) that starts out small and expands over an hour or so until it just disappears off the edge of my vision. Then I'm just wasted, fatigued, and fuzzy-headed for several hours. But no actual headache.
I've had maybe 6 episodes of this over the last 10 years.
