Here's an explanation of vitreous detachment from the Cleveland Clinic. I'd add that while the vitreous is actually separating from the back of the eye, it can tug at the retinal. That is why my doc saw me regularly for about six weeks. He just wanted to keep an eye--pun intended--on it, especially in light of my severe myopia. While I think that's the prudent approach, I would agree with Muirenn that there's really no real reason to panic. This is a normal occurrence for many. I was a bit younger than most when it happened and it happened, ironically, in both eyes within a week. The doc thought that was pretty unusual.