Hello again - I am worried about your son's eyes. Has he done any cleanses at all? A colon cleanse or a liver flush? What are his eating habits at this time? Any other "strange" symptoms going on? The eyes are so sensitive and so precious - I just want to know more so maybe I can help you figure this thing out.
Let me add this: I called my "real doctor" cousin and he said that floaters are more common in older folks than younger ones due to the gel-like substance that the eyeball is made of - it shrinks with age - and gets real stringy and that causes shadows which are "floaters". He said it's pretty uncommon for a 21 year old to have severe floaters of this nature. The only surgery for the most severe cases is this - the eye surgeon sucks out the gel and replaces it with a saline solution.
I think you're heading in the right direction. I hope this helps.