What are floaters?

Floaters are tiny black-shaped specks that seem to drift or move in your field of vision. You may see them more clearly when looking at a plain background, such as a blank wall or a blue sky. Floaters are actually tiny clumps of gel or cells inside the vitreous, the clear jelly-like fluid that fills the inside of your eye. When people reach middle age, the vitreous gel may start to thicken or shrink, forming clumps or strands inside the eye. Floaters can have different shapes, such as little dots, circles, lines, clouds, or cobwebs. Often, patients describe seeing tiny insect-like creatures, for example, “mosquitoes”.

Though these objects look like they are approximately 5 to 15 cm in front of your eye, they are actually floating inside the eye. What you see is not actually the floater itself, but the shadow that it casts onto the retina, the nerve layer at the back of the eye that senses light and allows you to see. Typically, floaters move as your eyes move. They appear to zoom away when you try to look directly at them, and drift slowly when your eyes stop moving.

Risk Factors for floaters

Age is a large risk factor for floaters. About one-quarter of people have some vitreous shrinkage with floaters by their 60s; that rises to about two-thirds of 80-year-olds. People who are very nearsighted (high myopes) are at greater risk of developing floaters earlier in life and are also at a greater risk of a retinal tear or detachment. Inflammation inside the eye (uveitis), diabetes, previous eye injury and recent intraocular surgery such as cataract surgery are also risk factors for developing floaters in the eye.

The impact of floaters

Usually, floaters are harmless and the optometrist might even confess to having floaters as well or tell you about a friend or relative that has this. Although most people tolerate floaters just fine, others feel that floaters affect their vision and disrupt their ability to read.

Floaters are of concern if they get unusually large in a short time. Floaters often occur when the vitreous gel pulls away from the back wall of the eye, causing a posterior vitreous detachment. In some cases, the retina can tear as the shrinking vitreous gel pulls away from the wall of the eye. A torn retina is always a serious problem, since it can lead to a retinal detachment.

The appearance of floaters may be alarming, especially if they develop suddenly. You should see an Eye Care Professional right away if you suddenly develop new floaters.

Patient who has a floater, attempting to swat an “insect” in the line of vision. P. Ramkissoon, 2018.

What are flashes?

Flashes are sparks or strands of light that flicker across the visual field. When the vitreous gel inside your eye rubs or pulls on the retina, you may see what looks like flashing lights or lightening streaks. Some people compare them to seeing “stars” after being hit on the head. The vitreous provides a pathway for light coming into the eye through the lens. The vitreous connects to the retina, the patch of light-sensitive cells along the back of the eye that captures images and sends them to the brain via the optic nerve. Changes to the vitreous which causes tugging of the retina can trigger flashes. You might see flashes on and off for weeks, or even months.

Flashes and migraines

Sometimes, certain people have light flashes that look like jagged lines or heat waves. These can appear in one or both eyes and may last up to 20 minutes. This type of flash may be caused by a migraine. A migraine is a spasm of blood vessels in the brain. When you get a headache after these flashes, it is called a “migraine headache.” But sometimes you only see the light flash without having a headache. This is called an “ophthalmic migraine” or “migraine without headache.”

Risk Factors for flashes

As people age, it is common to see flashes occasionally. Additionally, caucasians, people with genetic predisposition and high myopes are more likely to have flashes.

The shrinking vitreous can tug on the retina and pull away from it. This condition, called a posterior vitreous detachment, is common, and usually doesn’t threaten vision. In about one in six people, a posterior vitreous detachment causes the retina to tear. Fluid from inside the eye can then seep through the tear and separate the retina from the tissues that nourish it. This separation, called retinal detachment, can lead to permanent vision loss.

Management and treatment of floaters and flashes

While some floaters may remain in your vision, many of them will fade over time and become less bothersome. If floaters become a nuisance, for example, when reading, move your eyes up and down, or left and right. This can shift the floater and may provide temporary relief. Even if you have had some floaters for years, you should have an eye examination immediately if you notice new ones.

The treatment for floaters and flashes depends on the underlying condition. While not all floaters and flashes are serious, you should always have an eye examination to make sure there has been no damage to your retina. You should see your Eye Care Professional urgently if:

  • One new, large floater or “showers” of floaters appear suddenly
  • You see sudden flashes of light, especially if these flashes are persistent
  • You notice other symptoms, such as the loss of side vision or if it looks as if a shade or curtain is being drawn over your field of vision.

There is no specific treatment for separation of the vitreous gel from the retina, however, treatment is necessitated for retinal tears. Retinal tears can be treated several ways. Laser photocoagulation entails making a series of tiny burns around the retinal tear to fuse the retina to the back wall of the eye. This creates a barrier of scar tissue that stops the tear from getting bigger. A procedure called cryopexy which uses extreme cold, does much the same thing. Cold and laser light can also be paired with the injection of a gas bubble into the eye (pneumatic retinopexy) to repair a detached retina. Two operations, scleral buckling and vitrectomy, can also be used to reattach a retina. If a tear is detected early, treatment can prevent the retina from detaching.


Floaters and flashes become more common as we grow older. While most floaters and flashes are not serious, you should always have a comprehensive eye examination by an Eye Care Professional to make sure there is no imminent damage to your retina.

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