I too have floaters. They are not parasites. When the gel in the eyeball starts to not get gelly like when we are young, then these things begin. They are harmless but very, very annoying.
I am sure there is some way of getting rid of them, but until then, unfortunately, you will have to put up with them.
I have heard of an operation called vitreology or something like that, which is supposed to help but.......