Floaters are shadows or dark objects that "float" across your field
of vision. Floaters may appear as dark specks, strings, or cobwebs that float
through the eye.
Many people begin to see floaters as they get older and their eyes
age. If floaters have been present before, or if they occur with a diagnosed
migraine headache, this condition is usually not serious. They are usually
caused by tiny bits of solid tissue that collect in the thick fluid that fills
the center of the eye (vitreous gel), blocking light to the retina.
Sudden development of floaters or black dots may mean that a
retinal blood vessel has broken and is bleeding into the middle of the eye.
This condition, called vitreous hemorrhage, results from the vitreous gel
tugging on the retina. It may also be a sign of a serious retinal tear, which
requires immediate medical attention.