In response to top of thread, retinal detachment does usually start with new floaters.
My first floater came with an unusually timed cluster headache ( like a migraine but usually with predictable timing ) so I had accompanying visual auras. Because I didn’t recognize it as a cluster I described it to the on call eye doc as new floaters and sparkles. That got me an emergency trip to optical ER and a slightly disappointed surgeon.
I thought I had them when I was young, but I learned they were just a form of phosphenes.
https://en.m.wikipedia.org/wiki/Blue_field_entoptic_phenomen...
They do indeed “float”. If I move my eyes they move with them, then have momentum when I stop moving my eyes. They’re way more visible against static, bright backgrounds (like blue sky) but I can see them in indoor lighting, too.
I’ve had them since I was very young. The white flashes you’re referring to I’ve only noticed recently, and are very different things. They do require a bright blue sky for me to see them.
They do look a whole lot like things we saw in biology class under microscope.
Sometimes it worries me, but the condition is "stable".