I have been to the eye doctor already and they told me I was perfectly fine, or at least they could not see anything. I have floaters too, worse in my right eye, althogh I have some in my left too. The weird problem seems to follow that proportion, more in my right, less in my left.

This is the problem: if I look at a fixed object, and suddenly turn my head, this weird dark ring develops in vision. Its sort of like what you see when you push on the side of your eye but not as intense, and in the front rather than the side of my vision.

It is much worse when I first wake up in the mornings, then just moving my head seems to trigger it.

I'm really worried about this, the doctor can't see it, can anyone give me a vague idea of what it might be because I can't find anything on the net.