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Eye floaters: Experts discuss when you should be concerned

  • Category: General, Eye Care
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  • Written By: Boulder Community Health
Eye floaters: Experts discuss when you should be concerned

Eye floaters are small dark shapes that float across your field of vision and can look like black or gray specks, strings, squiggly lines or even little cobwebs. They may seem to appear out of nowhere or dart in another direction when you try to look at them.

“Floaters are common symptoms that usually occur because of age-related changes in your eyes. In fact, 75% of people aged over 65 experience floaters, and they are usually harmless,” said board-certified retinal specialist Geeta Lalwani, MD, of Rocky Mountain Retina Associates.

However, when floaters and flashes suddenly appear, it is important to consult with an ophthalmologist in a timely manner to determine if the symptoms are the warning signs of retinal tear or retinal detachment, as Dr. Lalwani and her co-presenter and practice partner, Vlad Matei, MD, stated in a recent free online health lecture.


Watch Treating Eye Floaters


What causes floaters?

Floaters are most commonly the result of changes in the vitreous humour, which fills the inside of the eye between the lens and the retina. The vitreous humour is enclosed in a membrane, and this is attached to the retina at the back and the lens at the front.

As we age, the vitreous humour shrinks and, as it does, it can pull on the retina. This can cause flashes because the pulling triggers nerves in the retina and they send signals to the optic nerve. This is followed by floaters.

“Eventually the vitreous membrane tends to pull right off the retina, a condition called posterior vitreous detachment or PVD. This condition is harmless, and it happens to almost everyone eventually,” said Dr. Matei. “Most often the vitreous never completely separates and remains anchored. But sometimes, as the vitreous pulls on the retina, it can tear it, causing a retinal tear or a retinal detachment.”

Symptoms of a PVD

Symptoms are the same if you have a PVD with or without a retinal tear:

  • Sudden onset of a large flash or flashes, which can look like lightening or camera flashes
    • Often arc-shaped and in the part of vision closer to your ear
    • More visible in dark environments
  • Followed by appearance of floaters in your view
    • There may be a large floater more prominent than the others
    • May be seen as a “haze,” “film” or “screen” over the vision
    • Floaters may increase over several days

Is PVD serious?

Floaters from PVD are usually not serious. “Yet in at least 5 to 10% of the time that PVD happens, it tears the retina and/or causes a retinal blood vessel. Most patients with retinal tears often progress onto a retinal detachment, which is a very acute emergency. When left untreated, retinal detachment can often lead to permanent blindness,” warned Dr. Lalwani.

Dr. Matei added, “A retinal detachment, on the other hand, starts as a dark black curtain coming up or down or across your vision from any direction. It typically progresses over a few days to a complete retinal detachment. Therefore, it is important to see a specialist when you first have a retinal tear before it progresses treatment of a retinal detachment, which usually requires surgery.”

Vitreous Hemorrhage

Often when the vitreous separates from the retina it can tear a blood vessel, which is called a vitreous hemorrhage.

“A vitreous hemorrhage causes patients to have not only just floaters, but sort of reddish tint or darker colored vision, like they're looking through a screen. Often these patients can experience a significant decrease in vision but it is central vision that’s affected as opposed to retinal detachment loss of vision will always come from the side,” Dr. Matei said. “Whenever we see blood, we worry that not only did it tear a blood vessel but did it possibly cause a retinal tear as well.”


Just as with symptoms of a heart attack or stroke, you need to see your doctor right away with sudden flashes or floaters.

“If we see a a retinal tear without a retinal detachment, we can actually treat that with a low-risk, in-office laser procedure called laser retinopexy,” said Dr. Lalwani. “The laser applies small scars around the tear to prevent fluid from going into it and detaching the retina. There’s no cutting, minimal discomfort, and treated retinal tears virtually never affect vision.”

If floaters still remain a problem after laser retinopexy, there’s a microsurgical procedure used by retina surgeons called pars plana vitrectomy (PPV).

Dr. Lalwani explained, “A vitrectomy is the first step of all the surgeries that we do for other diseases as well – not just for floaters. PPVs can typically be performed under local anesthesia and most patients leave the eye surgery center within 1-2 hours after surgery, similar to cataract surgery.” We discuss the individual risks and benefits at length with patients before proceeding with a vitrectomy for floaters.

To make an appointment with either Geeta Lalwani, MD, or Vlad Matei, MD, of Rocky Mountain Retina Associates call 303.900.8507.

Click here to view/download a PDF of slides shown during this lecture.