Floaters and Flashes: What They Mean and When to See a Doctor

You’re looking at a blank wall, or maybe the sky, and suddenly-there it is. A dark spot drifts across your vision. Then a flicker of light, like a spark behind your eyelid. You blink. It’s gone. Then it comes back. If this has happened to you, you’re not alone. Around 75% of people over 65 experience floaters and flashes at some point. Most of the time, they’re harmless. But sometimes, they’re a warning sign you can’t afford to ignore.

What Are Floaters and Flashes?

Floaters are those little specks, threads, or cobweb-like shapes that seem to drift when you move your eyes. They’re not on your eye’s surface-they’re inside, floating in the vitreous, the clear gel that fills the space between your lens and retina. As you age, this gel slowly breaks down. Collagen fibers clump together, casting shadows on your retina. That’s what you see.

Flashes are different. They’re not objects. They’re lights. Brief streaks, sparks, or lightning-like bursts, usually at the edge of your vision. These happen when the shrinking vitreous tugs on the retina. Your retina doesn’t sense light from the outside-it senses pressure. So when it gets pulled, it sends a signal to your brain that looks like a flash of light.

Both are symptoms, not diseases. But knowing the difference between normal aging and something serious can save your sight.

Why Do They Happen? The Science Behind the Vitreous

Your eye’s vitreous is mostly water-99%-with a network of collagen fibers holding it together like a sponge. Around age 40, that sponge starts to dry out and shrink. This is called vitreous syneresis. By your 60s or 70s, it’s common for the vitreous to pull away from the retina entirely. This is called posterior vitreous detachment (PVD). It happens in about 66% of people over 70.

When the vitreous detaches, it can tug on the retina. Sometimes, that tug is gentle. You get a few new floaters and maybe a few flashes. That’s usually PVD, and it’s normal.

But sometimes, the pull is strong. If the vitreous is stuck tightly to a weak spot on the retina, it can tear the retina as it pulls away. That’s when things get dangerous. A retinal tear can lead to a retinal detachment-a sight-threatening emergency.

How to Tell the Difference: Benign vs. Dangerous

Not all floaters and flashes are the same. Here’s how to tell if you’re dealing with a harmless change or something urgent:

• Benign PVD: A sudden shower of a few new floaters, maybe one or two flashes over a day or two. Vision stays clear. No curtain or shadow. Symptoms fade over weeks or months as your brain learns to ignore them.
• Warning signs: A sudden burst of many new floaters (like a handful of black dots), persistent flashes (repeating every few seconds), a dark shadow creeping across your vision, or sudden blurry or lost peripheral vision. These are red flags.

The biggest clue? Timing and pattern. If flashes come in clusters-three or four in a row within minutes-you need to get checked today. If you’ve had one or two flashes over a week and no new floaters, it’s still worth an eye exam, but not an emergency.

Who’s at Higher Risk?

Some people are more likely to have complications:

• People over 65: Risk of PVD climbs sharply after 65.
• Nearsighted individuals: Longer eyeballs mean more tension on the retina. PVD can hit them 10-15 years earlier.
• People with diabetes: High blood sugar can weaken retinal blood vessels. A bleed into the vitreous can mimic floaters but is far more serious.
• Those with eye trauma or surgery: Even old injuries can cause late-onset vitreous changes.

If you’re under 50 and suddenly get floaters and flashes, don’t assume it’s aging. It’s less likely to be PVD and more likely to be something else-like inflammation, bleeding, or a tumor. Get it checked.

When to See a Doctor-Immediately

You don’t need to wait for symptoms to get worse. If you notice any of these, call your eye doctor or go to an emergency eye clinic the same day:

• Sudden increase in floaters (especially if they look like a cloud or shower)
• Flashes that repeat over seconds or minutes
• A dark curtain or shadow moving across your vision
• Loss of side vision
• Sudden blurry vision that doesn’t clear up

These aren’t guesses. These are the signs of a retinal tear or detachment. If caught early, a tear can be sealed with laser treatment in minutes. If it becomes a detachment, surgery is needed-and vision loss can be permanent.

What Happens at the Eye Doctor?

Your eye care provider won’t just look at your eyes-they’ll dilate your pupils. That’s the only way to see the retina clearly. They’ll use a special lens to check for:

• Retinal tears or holes
• Vitreous hemorrhage (blood in the gel)
• Signs of detachment
• Other conditions like inflammation or diabetic changes

If everything looks normal, you’ll likely be told to monitor symptoms and come back if anything changes. If there’s a tear, treatment is usually quick and painless. A laser burns a small circle around the tear to seal it. No hospital stay. No recovery time.

Can Floaters Be Treated?

Most people don’t need treatment. Over six months, the brain adapts. The floaters settle lower in the eye, out of your central vision. They don’t disappear, but you stop noticing them.

There are treatments-but they’re not for everyone.

• Laser vitreolysis: A laser breaks up large floaters. It’s available in some clinics, but not widely covered by insurance. Results vary. It doesn’t work for everyone and carries a small risk of retinal damage.
• Vitrectomy: Surgery to remove the vitreous. Reserved for severe cases where floaters completely block vision. It’s invasive, carries risks like cataracts and infection, and is rarely recommended just for floaters.

For most people, patience is the best treatment.

What You Can Do Right Now

If you’ve just noticed floaters or flashes:

• Don’t panic. Most cases are harmless.
• Don’t wait. Schedule an eye exam within 24-48 hours, even if symptoms seem mild.
• Write down what you’re seeing: How many floaters? When did they start? Are flashes happening repeatedly?
• Don’t drive if your vision is blurry or you have a shadow in your sight.

If you’ve had PVD before and notice new symptoms, don’t assume it’s the same thing. New changes mean new evaluation.

Final Thought: Your Eyes Are Unique

Floaters and flashes are common. But they’re not always normal. The difference between a harmless aging change and a sight-threatening emergency often comes down to timing and pattern. One doctor’s rule of thumb: If you’re unsure, get it checked.

The good news? Most people who see a doctor get a clean bill of health. The better news? If something is wrong, catching it early means you can protect your vision with a simple, quick procedure.

Don’t risk it. Book your eye exam. It takes less than an hour. Your sight is worth it.