Omg, how ironic this would be the first post I find on this site. I've been having after images, tracers, floaters, visual snow, visual migraines, ringing/roaring in the ears, the whole nine yards for 2 years now. Been to many doctors and I know it's not to do with our eyes. It's a neurological thing. Like our sensors are delayed, so we see more noise because it doesn't process as fast. At least that's what I've been led to believe with my issues.
It sent me in to around the clock, nonstop panic attacks for 3 months straight that caused me to drop out of school and move back in with my mom (I lived with my grandparents junior year of highschool). It still triggers my anxiet sometimes when I can't ignore it or I'm just in one of those moods where I can't rationalize my hypochondria. Like tonight, which is why I made this account.
ANYWAY. The main point is, it's most likely a harmless quirk you'll have to live with. Sometimes it's worse, sometimes it's hardly noticeable. Just try and remember you arn't in any danger. One thing that really helped me was to STOP SEARCHING ABOUT IT ON THE WEB. I know it's hard, but once I forced myself not to look it up anymore, it because 10 times easier to try and ignore.
Sorry this is so long. Just felt like I'd share my story of battling with this frightening visual disturbance.