When I had a steroid injection directly into the eyeball, I had thread-like floaters for a couple of weeks, thinner than any thread you've ever seen, and now one month after cataract surgery, I'm having them again.
I figure that's from the steroid drops to prevent infection after the surgery, right? Didn't happen immediately. Both eyes.
I know that the floaters are from the cortisone itself after it is injected. It takes awhile to dissolve. When first injected, it is a large dark blob.
I'm not sure about after a cataract operation. Maybe it is residue from the operation, blood and debris. It will disolve on it's own in time.