@ObsidianUrbex
Forgive me if this is a repost - I tried earlier and I think it failed...
Anyway:
This is really odd. I've read the replies thus far in the thread and a common theme seems to be pain and or vomiting and/or diarrhea.
Mine is not like that, so I probably need to talk to my GP!
On odd occasions, I will catch a 'sharp' light reflection from something and it will 'stick' in my vision. At that point I know I cannot drive or watch TV or similar for at least half an hour.
Then I start getting the 'kaleidoscope vision' thing in an arc around that point (which is always in the centre of my view). That arc will grow wider, until after about 25 mins, it has expanded outside my field of view, at which point normal life may now continue.
I can confirm however that the advice about a dark room or subdued light helps me a lot when that is going on.
#PeopleAreWierd