Hey stringeye,
     The dark feather sounds like the vitreous frill, probably with some blood attached. I initially had a dark vitreous frill with blood attached--it was an arc on the edge of my vision with black marks on it. Eventually the blood dissolved, but the vitreous frill remained--it was semi-transparent, and very quickly moving arc in my peripheral vision. In my case the frill was so bad, that I had to go for another FOV with Dr. Patel. He trimmed the frill. Right now, 1.5 years after my final FOV, there is still a slight vitreous frill arc, but I can see it only in very bright light environment, when I move my eye quickly. It's not much of a bother. There is only so far you can trim the frill. In my case, Dr. Patel said, that he dares not risk trimming the frill any further because, I had several retinal tears (this was a couple of years before my FOVs, which were lasered), and if he works close to the laser marks there is some risk of RD. So good doctors not only understand what the risks are but will work to minimize them, even if the outcome as a result isn't 100% perfect. In my case what remains of my vitreous frill hardly bothers me at all--my biggest issue is the small cataract that occurred right after my first FOV surgery with Dr. Charles. I suspect that he touched my crystalline lens with his instrument.

Edited 1 time by Michael Jan 13 12 6:06 PM.