Sounds like a scintillating scotoma. It's a kind of migraine that sometimes preceeds, or comes with or without the headache usually associated with migraine. I

Sounds like a scintillating scotoma. It's a kind of migraine that sometimes preceeds, or comes with or without the headache usually associated with migraine. I get them occasionally. Definitely don't want to be driving when it happens. https://en.wikipedia.org/wiki/Scintillating_scotoma https://en.wikipedia.org/wiki/Scintillating_scotoma https://duckduckgo.com/?t=ffab&q=scintillating+scotoma&iax=images&ia=images https://duckduckgo.com/?t=ffab&q=scintillating+scotoma&iax=i...