Our Readers Want to Know: What Causes Floaters and Should I Be Worried About Them?

Editor’s note: One of the many benefits associated with an online information center and website, such as VisionAware, is the ability to track readers’ search terms [i.e., information readers are seeking as they search online]. Of particular concern to many readers are the presence and disease implications of floaters, as evidenced by the following searches:

  • Do floaters go away after a while?
  • I’ve had a sudden onset of a shower of floaters. What does this mean?
  • I have floaters after laser treatment/eye injection/eye surgery. Is this a problem?
  • Can floaters cause a retinal tear?

An Answer from Mrinali Patel Gupta, M.D.

Dr. Mrinali Patel Gupta

Dr. Gupta graduated with distinction with a Bachelor of Science in Biology, summa cum laude and Phi Beta Kappa, from Duke University College of Arts and Sciences in Durham, North Carolina. She completed her M.D. degree at Duke University School of Medicine, where she was elected to the Alpha Omega Alpha academic honor society.

During medical school, she also completed a one-year research fellowship as a Howard Hughes Medical Institute/National Institutes of Health Research Scholar at the National Eye Institute in Bethesda, Maryland. She pursued internship training at Memorial Sloan-Kettering Cancer Center in New York.

Dr. Gupta completed her Residency in Ophthalmology at Harvard Medical School/Massachusetts Eye & Ear Infirmary, followed by a Fellowship in Vitreoretinal Diseases and Surgery at Weill Cornell Medical College/New York-Presbyterian Hospital in New York, NY. Currently, she is an Assistant Professor of Ophthalmology in the Vitreoretinal Surgery Service at Weill Cornell Medical College, where she combines an active clinical and surgical practice with research in retinal disease and education of residents and fellows.

What are Floaters?

As their name implies, floaters are usually small, black shapes that look like spots, squiggles, or threads, and “float about” in one’s vision. They generally move as the eyes move, and are most noticeable against a plain bright background, such as a white or light-colored wall.

What Causes Floaters?

There are a number of conditions and changes within the eye that can cause floaters. These are the most common:

  • Changes in the vitreous: The inside of the back part of the eye is filled with a jelly-like substance called vitreous. The vitreous is attached to the retina, which is the thin, light-sensitive tissue that lines the inside surface of the eye. Much like the film of a camera, cells in the retina convert incoming light into electrical impulses. These electrical impulses are carried by the optic nerve to the brain, which finally interprets them as visual images.
  • As a person ages, the jelly-like vitreous becomes more liquefied and areas of the vitreous can condense and acquire a “stringy” consistency. These strings or strands of vitreous can be perceived as floaters.
  • Posterior vitreous detachment (PVD): As the vitreous liquefies, it also shrinks and pulls away from the retina. This process is called a posterior vitreous detachment, or PVD. Many people develop posterior vitreous detachments and never experience symptoms, whereas others may notice new floaters. In general, a vitreous detachment is not considered an ocular emergency.
view of the eye with vitreous

The vitreous: A side view of the eye with the vitreous gel (in blue)
filling the inside of the back part of the eye and attached to the retina.
Source: Courtesy Mrinali Patel Gupta, M.D.,
Weill Cornell Medical College, New York

view of the eye with posterior vitreous detachment

A posterior vitreous detachment (PVD): the vitreous gel (in blue)
shrinking and pulling away (detaching) from the retina.
Source: Courtesy Mrinali Patel Gupta, M.D.,
Weill Cornell Medical College, New York

  • Retinal tear or detachment: In some cases, as the vitreous is peeling away from the retina and detaching, it can pull so hard in areas of firm attachment that it tears the retina. Therefore, any person with a PVD should have a careful retinal exam to rule out an associated tear. As the retina tears, a retinal vessel may be torn or damaged, leaking blood into the vitreous. This blood, called a vitreous hemorrhage, may also produce floaters.

A tear in the retina is of great concern, because it can extend and allow fluid to enter through the tear and separate the retina from the underlying tissue. To picture how this happens, imagine a rip in the wallpaper in the bathroom. That is like a retinal tear. If the rip is not repaired, over time, steam from the bathroom shower can get behind the tear; eventually the entire sheet of wallpaper may begin to peel and fall off. A similar process occurs when a tear is untreated and the retina comes off, or detaches.

Anyone can develop a retinal tear and detachment, but they are more likely to occur in persons who are nearsighted, older, have recently undergone cataract surgery, or have sustained a trauma to the eyes.

Please note: Retinal tears often lead to retinal detachment. While retinal tears usually do not cause vision loss and can be repaired effectively through a non-incisional [i.e., no surgical cuts involved] laser or cold therapy (cryotherapy) procedure in the office without anesthesia, retinal detachments almost always cause vision loss and usually involve incisional surgical repairs in an operating room. Therefore, it is critical to be evaluated promptly, because diagnosis and treatment of a retinal tear before it results in a retinal detachment can be vision-saving.

What Should You Do if You Notice Floaters?

Anyone who notices new floaters should undergo a dilated eye examination. The doctor may use a Q-tip or small instrument to push gently on the eye to look at the far edges of the retina not visible through a routine examination.

Anyone with a prior history of floaters who notices a new shower of floaters, flashing lights, or a curtain or shade “coming down over one eye” should undergo a prompt dilated eye examination. These may be signs of a retinal tear or retinal detachment.

How are Floaters Treated?

  • In all cases, the underlying cause of the floaters should be treated. The underlying cause for any inflammation or bleeding should be identified and treated accordingly.
  • If the floaters are due to changes in the vitreous or to posterior vitreous detachment (PVD), no intervention is necessary. A dilated eye examination should be performed to rule out an associated retinal tear or detachment.
  • In addition, many eye doctors may perform a follow-up exam in several weeks to confirm that a new tear or break has not developed in the retina. Over time, the floaters may decrease, and in many cases, the brain learns to ignore these floaters.
  • The only effective way to remove floaters from the vitreous or from posterior vitreous detachment (PVD) is to surgically remove them. In rare cases, a vitrectomy can be considered if floaters are causing significant visual symptoms. However, it is important to weigh the risks versus benefits of such a procedure.

For more information about treatments for retinal tears and retinal detachments, see Floaters, Retinal Tears, and Retinal Detachments on the VisionAware website.

Additional Information