Q. What are floaters?

A. Most people will experience floaters at some time in their lives. The retina lines the inside of the eyeball like wallpaper. The inside of the eyeball is filled with a clear gel called vitreous. Floaters are particles that "float" in the vitreous cavity. They appear as small dots, fine strings or filaments, flyspecks or gooey cobwebs. When you look at a bright light or white surface, these particles cast shadows on the retina. As the flecks move in the vitreous gel, the shadows appear to float, hence, the term "floaters."

Floaters commonly result from the separation of the vitreous gel from the retina. This separation is known as posterior vitreous detachment and should not be confused with retinal detachment. When the vitreous gel separates, it usually pulls away a few flecks of debris from the retina. These may appear as small dots or cobwebs. When the vitreous pulls away suddenly, not only can it produce floaters, it can also create a tear in the retina.

Whenever the retina is torn, the watery component of the vitreous can seep beneath the retina, and the retina can "peel" away from the wall of the eye. This is called retinal detachment and, without treatment, leads to blindness. Therefore, it is important to be evaluated by an ophthalmologist with a sudden onset of floaters. If a retinal tear is discovered, it can be treated in the office. However, once the condition has progressed to a retinal detachment, surgery is usually necessary. Flashing lights also can indicate that the vitreous gel is pulling on the retina and, with the sudden appearance of floaters, is a warning sign of a possible retinal tear or detachment. Typically, if the retina is going to tear, it usually occurs within six weeks. So, if a person has had floaters for many months, or even years, the chance of having a tear is very low.

When diabetics have floaters, particularly if they are reddish-black, it could indicate bleeding in the eye and usually means the person will need laser treatment. Inflammatory diseases of the eye also can produce floaters and often is a signal that treatment is necessary.

In general, floaters do not require treatment. Over time, they tend to fade or shrink and become less noticeable. Because of the possibility of a retinal tear or detachment, floaters are a warning sign when they occur suddenly. A timely visit with an ophthalmologist is recommended.