Retina Services

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What are Floaters and Flashes?

Floaters and flashes are common visual symptoms that come from the vitreous, the gel that fills the inside of your eye.

Floaters appear as small specks of dust, dots, circles, lines, or cobwebs drifting through your field of vision. Although they can seem like flies or mosquitos hovering in front of your eye, they are actually bits of debris floating within the vitreous gel itself. As these clumps of debris drift, they cast shadows on your retina, and those shadows are what you perceive as floaters.

Flashes look like flashing lights, stars, or streaks of lightning in your vision. They occur when the vitreous rubs against or tugs on your retina, and they can come and go for weeks or even months. Seeing an occasional flash becomes increasingly common as we age.

What Causes Vitreous Floaters?

Vitreous floaters are caused by age related changes in the gel inside your eye. As we get older, the vitreous gradually liquefies and shrinks, and clumps or strands often form within it. You will usually notice floaters most when looking at something plain, such as a blank wall, a blue sky, or a computer screen.

When the shrinking vitreous gel separates from the back surface of the eye, the event is called a posterior vitreous detachment, and floaters frequently appear along with it.

Floaters are also more common in people with certain eye conditions and histories, including:

• Myopia, or nearsightedness, meaning you need glasses to see far away.

• Previous cataract surgery.

• A history of inflammation inside the eye, known as uveitis.

Are Floaters Dangerous?

By themselves, floaters are usually harmless. They tend to fade with time, the brain typically learns to tune them out, and they seldom require treatment or surgery. The reason floaters deserve attention is what they can accompany: a vitreous detachment, a retinal tear, or a retinal detachment, conditions that do require an eye exam.

When Are Floaters and Flashes Serious?

Floaters and flashes are serious when they are new, suddenly increasing, or joined by changes in your side vision. Most of the time floaters cause no problems at all, but certain features are warning signs that call for an exam with an ophthalmologist:

• New floaters.

• New or more frequent flashes.

• A shadow or grey curtain appearing in your peripheral (side) vision.

Flashes and floaters with these features can be symptoms of a retinal tear or retinal detachment. Both conditions are potentially serious and warrant immediate evaluation by a retina specialist.

Can Migraines Cause Flashes?

Yes. Flashes are sometimes associated with migraine headaches, and these migraine related flashes tend to look different from the typical kind. Rather than brief streaks of light, they usually appear as jagged lines or shimmering heat waves, and they can last considerably longer.

A migraine is a type of headache caused by a blood vessel spasm in the brain. Occasionally the visual flashes occur without the headache that usually follows. This experience is called an aura, an ophthalmic migraine, or a migraine without headache.

Why Do I See Flashes When I Rub My Eyes, and Why Won't Floaters Blink Away?

Seeing brief flashes or spots of light when you rub your eyes is normal and harmless. Pressing on the eye mechanically stimulates the retina, which responds the only way it can, by producing a sensation of light. It is the same effect as being hit in the eye and seeing stars. These pressure flashes stop as soon as the rubbing stops, which sets them apart from the spontaneous flashes caused by the vitreous pulling on the retina.

Blinking, on the other hand, will not clear floaters away, and that is actually a useful clue. Dust, mucus, or a tear film smudge sits on the surface of the eye and shifts or clears when you blink. Floaters live inside the eye, suspended in the vitreous gel, so they drift right through a blink unchanged and glide along as you move your eye. If a spot in your vision does not clear with blinking, it is almost certainly a floater rather than something on the surface of your eye.

Do Floaters Go Away on Their Own?

In most cases, yes. Floaters are dark spots or dots that move and drift as you move your eye, created by the shadows of vitreous gel clumps inside the eye. Over time they tend to settle and fade, and the brain becomes remarkably good at ignoring the ones that remain. Treatment is rarely needed.

The important exception is timing. Floaters and flashes become extremely common with age, but a sudden onset of new or increased floaters or flashes can signal a serious problem such as a retinal tear or retinal detachment. If that happens, call your ophthalmologist right away.

If you are experiencing new floaters, flashes, or changes in your vision, please contact Florida Retina Institute or call our office right away to speak with a member of our team. With 21 locations throughout Florida and Georgia, a retina specialist is always close to home.