First off, MRI was for arthritic neck, nothing serious & just another step down the tedious doctor road. 2nd, I ain't crazy. This was a 6:15AM thing w. me laying in the tube relaxed with earplugs + headphones trying to play rock music over the pounding sounds of the MRI machine. Eyes closed I noted a vision thing that I'll try to describe: a cloud formation forming in front of your eyes but really more like a nebula that would recede into the distance until it was just a point of light, then diminish & disappear, then repeat. Got my attention so I focused on the thing. It only happened during some sequences--the technician would say "OK, this is 3.5 minutes and will sound like a loud machine" etc. It repeated like a clock; you could count it off. It only happened during some of the sessions, the ones that were lengthy and more 'thrumming' than 'jackhammer'. I do pay attention to science + worked tertiary to the sciences for decades + have some knowledge of medical science/biochemistry etc. but this was a new one. Did a quick search on the subject and got nothing. Thinking the magnetic field was affecting something but unsure if retinal fluids or similar or nerve pathways or what. Any ideas? It did make the 30 minutes go faster.