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Patient Guide to Floaters and Flashes

Jun 11 2019

Posted In:

20/20 Blog

Palo Alto, CA – Patients often come to Dr. Vinit Mahajan M.D., Ph.D., associate professor of ophthalmology at Stanford University, concerned about the floaters and flashes of light they are experiencing in their peripheral vision. Although flashes and floaters naturally occur with age and usually do not lead to vision loss, together they can be a symptom of a serious eye disease. Getting an annual eye exam where an ophthalmologist dilates the eyes to examine the entire retina is important in preserving eye health.

What are floaters?

Floaters are grey-black, drifting shadows cast on the retina by microscopic vitreous fibers in the eye. They can appear as wisps, spots, thin strands, or wavy lines. They develop as we age and the vitreous gel inside the eye between the lens and the retina begins to break down and clump together. 

Mahajan said, “Most people have floaters, but they only become visible when looking at something bright, like a white wall or a blue sky, with very even illumination. They are often over looked until they increase in number.”

Can floaters cause vision loss?

Most floaters are harmless and will disappear within several weeks to several months. It is rare for floaters to become so numerous that they impair vision.

“In rare circumstances, however, floaters can be a sign of something more serious,” Mahajan said. 

Inflammation in the back of the eye, eye tumors, bleeding inside the eye, diabetic retinopathy, and a torn retina can all cause floaters. 

Mahajan emphasized, “A thorough eye exam with an eye surgeon, along with specialized imaging, can help determine the cause of floaters.”

Migraine headaches also can cause a unique form of visual dark spots, but patient symptoms are different. Usually there is a fixed dark area that goes away after several minutes.

When should I be seen for floaters?

A sudden onset of new floaters, an excessive number of black spots, floaters accompanied by flashes of light or eye pain, peripheral vision loss, or a dark area moving across your vision are all reasons to make an appointment with your eye surgeon. 

Is there a treatment for floaters?

If floaters are distracting, move the eyes up and down to shift the vitreous fluid around. Wearing sunglasses and reducing the brightness on computer screens and tablets can make floaters less noticeable. 

Mahajan said, “Over time the brain learns to ignore floaters, and they become less annoying.” 

If there are so many floaters that they block vision, occasionally vitrectomy surgery may be necessary to remove the clumped vitreous. 

Dr. Mahajan does not recommend laser therapy. 

What if my floaters are accompanied by flashing lights?

Many aging eyes will see occasional flashes of light. These flashes of light are usually harmless, but you should discuss them with your ophthalmologist during an eye exam. There is no treatment for these periodic, age related flashes, and people often get used to living with them.

However, if you suddenly start seeing repeated flashes of light, like a strobe light, this could be a sign that the vitreous has pulled on the retina causing it to tear, especially if you also have cloudy floaters or vision changes. See an eye surgeon immediately so quick steps can be taken to prevent blindness.Retinal tears frequently require treatment. If fluid passes through the tear and gets underneath the retina, this is a retinal detachment. Surgery is needed to repair a retinal detachment.

Migraines can also cause light flashes that are confused with light flashes from a retinal detachment. An eye surgeon can help patients determine the difference.

To make an appointment with Dr. Mahajan, please click here.

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