What causes floaters?
The front part of the eye is comprised of the cornea, which refracts the light coming into the eye. The lens focuses an image on the retina, which is like camera film in the back of the eye. The large space between the lens and the retina is filled with a gel known as the vitreous humor. It's a gel of the same consistency of the white of a raw egg. That gel has debris left over from the formation of the eye. So, if some debris in the vitreous humor floats between the front part of the eye and the retina, it casts a shadow on the retina, and we see this as floaters. At different times the debris moves more in line with a patient's line of sight, which is why floaters come and go.
Do floaters ever go away?
While they don't leave the eye, most patients eventually stop noticing floaters. The floaters are simply no longer apparent within the visual axis of the eye, the line of sight. Over time, gravity causes the floaters to sink down below the line of sight as the gel in the eye becomes more liquefied. Most floaters do tend to diminish with time.
Are floaters ever serious?
When people look at a blue sky or white clouds, they're apt to see floaters more often. But, if the number of floaters increases dramatically, or they change in nature from being wispy floaters to a multitude of tiny, little dot-like floaters, or they're associated with a flashing light or flashes of light, it may indicate a change from the normal floaters that almost all see to something more significant.