Brightside: Pretty much everyone has seen those weird transparent wormy things occasionally floating across their field of view. They always look a bit unnerving, as though some kind of bug is sitting on your eye. We decided it was time to answer the question: 'what are these things really?'
It turns out they're called 'muscae volitantes', which is Latin for 'flying flies'...but they're actually not flies at all, or any other kind of bug.
You've probably seen these things if you've ever screwed up your eyes to look at the sun (or seemingly for no reason at all)
These 'floaters' are actually made up bits of tissue, clumps of protein, or red blood cells inside the eye. We see them because they create shadows on the retina.
For the full story, try watching this fascinating little video.
Fuente: brightside.me