Black Spots Floating in Your Vision? Eye Floaters Explained, and When to Worry

You're looking at a clear blue sky or a white wall when a small dark speck drifts across your vision. You try to look straight at it, and it slides away. It might look like a thread, a tiny cobweb or a cluster of dots that moves every time your eyes do.

These are eye floaters. Most people describe them as black spots floating in vision, and almost everyone sees them at some point. Usually they're harmless. But a sudden change in your floaters can also be an early warning of a retinal tear. Knowing which is which can protect your sight.

What Are Eye Floaters?

The inside of your eye is filled with a clear, jelly-like substance called the vitreous, which helps the eye keep its round shape. With time, the vitreous slowly turns more liquid, and tiny fibres inside it clump together.

When light enters the eye, these clumps cast shadows on the retina at the back of the eye. Those shadows are the black spots floating in vision that you notice. It's also why they move when your eyes move, and why they're easiest to see against a bright, plain background.

What Do Floaters Look Like?

Floaters aren't always round black spots floating in vision. People describe them in lots of ways:

• Black or grey dots or specks
• Squiggly lines or threads
• Cobwebs or thin, see-through strands
• A ring-shaped shadow
• Something like a small insect moving in front of the eye

Common Causes of Eye Floaters

Several things can cause black spots floating in vision. Some are part of normal ageing, and others need medical attention.

Age-related changes. This is by far the most common cause. From middle age on, the vitreous naturally shrinks and can pull away from the retina. This is called posterior vitreous detachment (PVD). It often brings a sudden new floater, sometimes with flashes. It's usually harmless, but it can occasionally tear the retina, so it always needs to be checked.

Short-sightedness (myopia). People with higher minus powers tend to get floaters earlier. Their eyes are longer, so the vitreous changes sooner.

Eye surgery or injury. Floaters can appear after cataract surgery or a blow to the eye.

Diabetes. In diabetic retinopathy, abnormal blood vessels can bleed into the vitreous and cause dark spots, streaks or a sudden haze.

Inflammation inside the eye (uveitis). Inflammatory cells in the vitreous can show up as floaters, often with redness, pain or blurred vision.

Are Sudden Black Spots in Vision an Emergency?

They can be. A few black spots floating in vision that you've had for months or years without any change are usually nothing to worry about. It's a different story when floaters appear suddenly or come with other symptoms.

See an eye specialist the same day if you notice:

• A sudden shower of new floaters, or one large new floater
• Flashes of light, like a camera flash or streaks of lightning, especially at the edges of your vision
• A dark curtain or shadow spreading across part of your vision
• Sudden blurring or loss of vision along with floaters
• New floaters after an eye injury

These can be signs of a retinal tear or retinal detachment. When a tear is caught early, it can often be sealed with a quick laser procedure in the clinic. If it's missed and the retina detaches, you'll need surgery, and the longer it's left, the lower the chance of full visual recovery.

Sudden Floaters in One Eye

New floaters usually show up in one eye at a time, because the vitreous changes separately in each eye. That doesn't make them less important. A sudden new floater in one eye should be examined with a dilated eye check within 24 hours, especially if you're over 50 or have high myopia.

Do Floaters Go Away?

Most black spots floating in vision don't disappear completely, but they often become much less noticeable over weeks to months. Some clumps settle lower in the eye, out of your line of sight. Your brain also learns to tune them out, a process called neuro-adaptation.

Until then, a few things can help:

• Look up and down. This can shift a floater out of the way for a while.
• Wear sunglasses in bright light. Floaters are less obvious when there's less glare.
• Try not to chase them with your eyes. Following them only makes you notice them more.

How Are Floaters Diagnosed?

Your eye specialist will put drops in your eyes to widen your pupils. This lets them examine the whole retina, especially its outer edges, where tears usually happen. It doesn't hurt, but your vision will be blurry and sensitive to light for a few hours afterwards, so bring sunglasses and don't drive yourself home. If needed, an ultrasound scan or OCT can give a more detailed view.

Treatment Options

Harmless floaters usually need no treatment. You just need reassurance and a follow-up check if anything changes. If a retinal tear is found, laser treatment or a freezing treatment called cryotherapy can seal it and help prevent detachment. If the retina has already detached, surgery is needed to reattach it.

In rare cases, very large floaters can disrupt daily life for a long time. A surgical procedure called vitrectomy may then be considered, after a careful talk about the risks and benefits. Floaters caused by diabetes or inflammation are treated by managing the underlying condition.

Can You Prevent Floaters?

You can't fully prevent age-related floaters, but you can lower your risk of complications:

• Get regular dilated eye check-ups if you're over 40, have high myopia or have diabetes.
• Keep your blood sugar and blood pressure under control.
• Wear protective eyewear for sports or work where eye injuries are possible.
• Most importantly, don't ignore sudden changes.

Retina Care at The Eye Foundation

The vitreo-retina specialists at The Eye Foundation assess floaters and flashes with detailed dilated eye examinations and advanced retinal imaging. They can also treat retinal tears and detachments promptly. If you've noticed new floaters, flashes or a shadow in your vision, visit your nearest Eye Foundation hospital as soon as possible.

Frequently Asked Questions

Do floaters mean high blood pressure?

Floaters on their own aren't a sign of high blood pressure. But uncontrolled blood pressure can affect the blood vessels in the retina, so regular eye check-ups are a good idea if you have hypertension.

Can stress or lack of sleep cause floaters?

Stress doesn't cause floaters, but you may notice the ones you already have more when you're tired. New or sudden floaters should still be checked.

Can eye drops remove floaters?

No eye drop has been proven to dissolve floaters. Be cautious of products that claim to cure them.

I've had the same floater for years. Should I worry?

Stable, long-standing floaters are usually harmless. Mention them at your routine eye check-up, and see a doctor promptly if they suddenly increase or come with flashes.