I've been seeing them since I was a kid, 40 yrs or so ago now.
I've had floaters and the odd string of dead cells ocassionaly, but what we are talking about here is much smaller and there's millions of them.
I did notice a fews years ago, on a clear day that if you watch them carefully, they seem to move with your heart beat.
I think its some tiny stuff, much tinier than the floaters.
Maybe its the life force, orbs or maybe its just fluids on the surface of the eyes.
It doesnt worry me either way.