Myodesopsia detail

Floaters are deposits of various size, shape, consistency, refractive index, and motility within the eye. Floaters are visible because of the shadows they cast on the retina. As these objects exist within the eye itself, they are not optical illusions but are entoptic phenomena.

Floater. (2015, March 22). In Wikipedia, The Free Encyclopedia. Retrieved 17:00, May 1, 2015, from http://en.wikipedia.org/w/index.php?title=Floater&oldid=652946853

"Objects (e.g. cobwebs, threads, apparitions) form in the vitreous humor of the subject's eye, though these imperfections don't seem to be constrained to the oculus. Defects trace to something more internal(?) than the hyaloid canal. Deeper than the body. There is, in fact, something intensely wrong with this man."

Teterus, A. (1983). An examination of the iris and the id. Deft Perception Quarterly, 23, 101-110.