They can vary from one little spot to a full swirling kaleidoscope. I always equated them with
Headaches (like the shimmers before a migraine) and have dismissed them as TMS.
Hi Baseball,
I've had experiences like you describe. I got myself checked out at my local eye hospital A&E (ER) when it first happened and was told that 'Kaleidoscope Vision' (they used that term) can be caused by an ocular migraine (with or without a headache) and that episodes can be for around 10 to 20 minutes or so, but can last for an hour or more, and that they can affect one or both eyes. My KV/ocular migraine episodes were in one eye, the same eye each time (and were different to my floaters caused by vitreous gelly thickening and vitreous detachment)...and on two occasions I temporarily completely lost the sight in the affected eye.
This website gives a lot of details about ocular migraines
https://www.specsavers.co.uk/eye-health/ocular-migraines (Ocular Migraine - Symptoms, Causes & Treatment | Specsavers UK). Interestingly, it says that triggers for them include, excessive heat, exercise, dehydration, bending over and low blood sugar...so some of the triggers would therefore seem to tie in with your experience whilst playing baseball.
Interestingly, ocular migraines apparently happen when the blood flow to the eye becomes restricted due to a sudden narrowing of the blood vessels. Once the vessels relax, normal blood flow returns and symptoms clear and usually this will have no lasting damage to the eye. So, this would seem to possibly tie in with TMS reduced blood flow. (The NHS website
https://www.nhs.uk/conditions/retinal-migraine/ (Retinal migraine) does though of course give the caveat that "it's important to see an optometrist or medical doctor urgently if you suddenly lose your eyesight, particularly if it occurs for the first time. There are other more serious causes of sight loss that doctors will want to rule out.")
When I went to the eye hospital, thankfully, they couldn't pin the cause down to anything sinister. My eyes are misaligned for reasons that I'll spare you the details of, so they put it down to that triggering my KV/ocular migraines.
My cousin also had two bouts of KV/ocular migraine without headache (the first one for about 45 minutes and the second for around 15 minutes) about 5 years ago - 3 weeks apart - with no further reoccurrence. She was told that it's best to try to relax during an ocular migraine and let it run its course. She did this during her second episode, which may account for it only lasting 15 minutes compared to the 45 minutes duration of her first episode.
Heaven knows whether my and my cousin's KV/ocular migraine episodes were actually TMS or not -- I prefer to believe that they were.