Floaters get their name because they appear as small specks, strands or cobwebby-like dark areas that float around in your field of vision. Those floaters are clumps and strands of protein that are floating around in the vitreous humor of your eye.
By definition, floaters are anything suspended in the vitreous gel of your eye that casts a shadow on your retina. Sometimes blood, inflammation or a retinal tear can cause floaters. Most commonly, however, floaters appear as we age due to a posterior vitreous detachment, a normal part of the aging process.
What is vitreous humor?
The vitreous humor fills the vitreous cavity of the eye and that cavity is located in the space between your lens and retina. The vitreous humor that fills the vitreous cavity is a transparent, colorless, gel-like substance. The vitreous humor is mostly water with a small amount of collagen, sugars (glycosaminoglycans), and proteins.
The vitreous chamber is about 80% of the eye anatomy and the vitreous humor within it gives the eyeball its shape. The vitreous humor is the medium within which oxygen and nutrients travel from the front of the eye to the back because there are no blood vessels in that part of the eye to perform this function.
The vitreous is also the “shock absorber” of the eye. It absorbs and dampens the compression and rebound that occurs when you shake your head, engage in physical activities such as running or other sports, or when you suffer a head injury.
What causes floaters?
During the normal process of aging the vitreous loses viscosity. Viscosity is a fluid’s internal resistance to flow, but a good way to envision viscosity is the concept of thickness—water has low viscosity while honey has high viscosity.
The change in viscosity means that the vitreous humor changes from a thick gel-like substance to one that is thinner and more liquid-like and this change also changes the protein fibers that make up some of the vitreous and causes them to clump together and float through the less viscous vitreous humor. This protein clumping may cast a shadow on the retina.
A retinal tear is a common cause of floaters. Retinal tears may cause a retinal detachment, a potentially blinding condition. New floaters should always be reported to your doctor.
How are floaters treated?
Sporadic floaters without a retina problem don’t require treatment. Many times, the floaters become less noticeable and only occasionally float across your field of vision.
If floaters are severe and interfere with your vision and don’t go away after several months, you may need surgery to remove the vitreous. The surgery is called a vitrectomy and is the safest way to get rid of floaters that interfere with vision. There is also a technique to remove floaters using a laser, but that procedure may have a higher risk of damaging the retina.
A vitrectomy is performed by a retinal specialist who removes the vitreous along with the floaters and replaces it with purified water or a saline solution.
Discuss these options with your doctor.