I have lots of them, for many decades now. When I look against a white wall, it looks as if I was taking a look through a microscope and see all kinds of germs. It's distracting, and I try not to focus on it. My ophthamologist told me these are agglutinating collagen fibres, swimming inside the vitreous body of the eye. I'm been told it's very common for Hashimoto patients (which I am), and it is also related to Ehlers-Danlos (for which I was recently tested).