I used to get this as a kid mowing the lawn on a riding mower. After a couple hours, when you get off the mower the whole world seems like it's receding from you slowly.
After being a scuba diving assistant to instructor thru one summer, I had similar effect after spending close to 10 hours under water every day for weeks: when I lay down for the night on a flat bed and open my eyes, the whole ceiling would float like a water!
Trees outside were moving in the wind. Wasn't clear to me when the effect stopped...
This is crazy. Feels like it was revealed that my brain is no different than the AIs creating trippy art that Google made a while back. They just had a longer stare