Not sure if I can describe this very well, and it’s probably quite niche/abstract, but I’ll give it a go on the off chance that it has happened to at least one more person.
As a kid (and sometimes as an adolescent, but less frequently…and now never as an adult), my sense of perspective used to just get warped in this really odd fashion without any particular trigger, and it used to be pretty scary. Often happened when I was watching TV…and it was like my brain got confused by how there was a 3D dimension being portrayed by a flat screen…which translated into my eyes wondering if all 3D perception was a trick. I’d then start to focus intently on one thing in particular, but couldn’t look at the scene in general…a bit like when you think about breathing you can no longer do it naturally. Usually had to go into pitch darkness and forget about it completely for it to reset.
Not sure if this will make any sense to anyone…