What are floaters and flashes?

Floaters

You may sometimes see small specks or clouds moving in your field of vision. These are called floaters. You can often see them when looking at a white background or a blue sky. Floaters are actually tiny clumps of gel or cells inside the vitreous, the clear, gel-like fluid that fills the inside of your eye.

While these objects look like they are in front of your eye, they are actually floating inside it. What you see are the shadows they cast on the retina, the layer of cells lining the back of the eye that senses light and allows you to see. Floaters can appear as different shapes, such as little dots, circles, lines, clouds or cobwebs.

Flashes

When the vitreous gel rubs or pulls on the retina, you may see what look like flashing lights or lightning streaks. You may have experienced this same sensation if you have ever been hit in the eye and seen "stars." The flashes of light can appear off and on for several weeks or months.

As we grow older, it is more common to experience floaters and flashes as the vitreous gel changes with age, gradually pulling away from the inside surface of the eye.
If the vitreous gel shrinks and pulls away from the wall of the eye, the retina can tear. This sometimes causes a small amount of bleeding in the eye that may appear as new floaters.
A torn retina is always a serious problem, since it can lead to retinal detachment and loss of eyesight. You should see your ophthalmologist as soon as possible if:

Early Glaucoma Damage

Some people experience flashes of light that appear as jagged lines or "heat waves" in both eyes, often lasting 10 to 20 minutes. These are not flashes from the vitreous gel rubbing or pulling on the retina; instead, these types of flashes are usually caused by a spasm of blood vessels in the brain, called a migraine.

If a headache follows the flashes, it is called a migraine headache. However, jagged lines or heat waves can occur without a headache. In this case, the light flashes are called ophthalmic migraine, or migraine without headache. Contact your ophthalmologist if you experience these symptoms.

If you notice other symptoms, like the loss of side vision, you should see your ophthalmologist.

Who is at risk for floaters and flashes?

As we grow older, it is more common to experience floaters and flashes. This condition is more common in people who:

What causes floaters and flashes?

When people reach middle age, the vitreous gel may start to thicken or shrink, forming clumps or strands inside the eye. The vitreous gel pulls away from the back wall of the eye, causing a posterior vitreous detachment. This is a common cause of floaters. As we grow older, it is also more common to experience flashes.

The appearance of floaters and flashes may be alarming, especially if they develop very suddenly. To find out if a retinal tear or detachment is occurring, you should call your ophthalmologist right away if you notice the following symptoms (especially if you are over 45 years of age):

How are floaters and flashes diagnosed?

Floaters and flashes become more common as we grow older. While not all floaters and flashes are serious, you should always have detailed eye examination by an ophthalmologist to make sure there has been no damage to your retina.

When an ophthalmologist examines your eyes, your pupils may be dilated (enlarged) with eye drops. During this painless examination, your ophthalmologist will carefully observe areas of your eye, including the retina and vitreous. If your eyes have been dilated, you will need to make arrangements for someone to drive you home afterward.

How are floaters and flashes treated?

Floaters may be a symptom of a tear in the retina, which is a serious problem. If a retinal tear is not treated, the retina may detach from the back of the eye. The only treatment for a detached retina is surgery.

Other floaters are harmless and fade over time or become less bothersome, requiring no treatment. Surgery to remove floaters is almost never required.

Even if you have had floaters for years, you should schedule an eye examination with your ophthalmologist if you notice a sudden increase in the size or amount of floaters or a sudden appearance of light flashes - especially if these symptoms are accompanied by any change in your vision.

The American Academy of Ophthalmology recommends that adults with no signs or risk factors for eye disease get a baseline eye disease screening at age 40 - the time when early signs of disease and changes in vision may start to occur. Based on the results of the initial screening, an ophthalmologist will prescribe the necessary intervals for follow-up exams.

For individuals at any age with symptoms of or at risk for eye disease, such as those with a family history of eye disease, diabetes or high blood pressure, the Academy recommends that individuals see their ophthalmologist to determine how frequently their eyes should be examined.