Floaters and Flashes: When Are They a Medical Emergency?

Most people notice occasional spots, threads, or cobweb-like shapes drifting across their vision at some point in life. AKA floaters, they are generally harmless (benign) — although if they do cause bother, they can be reduced or removed through a simple laser treatment. Occasional flashes, which are when you see brief flickers of flashing lights in your vision, are also relatively common and are often related to normal aging changes inside the eye.

There are, however, instances when eye floaters and flashes are an emergency. Their sudden appearance can be a symptom of a retinal tear or retinal detachment, which requires urgent treatment.

So… How do you know the difference? The short answer that Dr. Brent Bellotte always tells patients is this:

“If you suddenly develop a shower of new floaters, flashing lights, a dark curtain or shadow in your vision, or any dramatic change in vision, seek professional advice immediately”.

This could be by calling or visiting an emergency eye center, such as the West Boca Eye Center, or — if you don’t have a specialist vision clinic close by, then visit your nearest ER.

When to Worry about Sudden Floaters and/or Flashes: An Emergency Triage Guide

At the back of the eye is a thin layer of light-sensitive cells that are critical for vision. It’s called the retina, and you can think of it as acting rather like a camera sensor. It receives light entering the eye and turns it into signals that the brain interprets as vision.

As you can imagine, this is a pretty important structure. Any damage to it has the potential to cause serious vision loss. This could be small, such as a microscopic hole, a larger tear, or even entirely peel away — a condition called retinal detachment”. Symptoms of this include, you guessed it, the appearance of sudden floaters and flashes. 

These can also be accompanied by the appearance of a dark shadow or curtain drooping down from the top of your vision. It’s generally painless, because there are no pain sensors at the back of the eye. It can, however, bleed into the jelly-like eye fluid (the vitreous), which is usually the reason for a sudden increase in floaters.

Flashes appear because the changes to the vitreous, which is generally the underlying cause of the detachment, stimulates the nerve pathway to the brain. This is interpreted as flickers of light.

Retinal tears and, in particular, detachment, require emergency treatment to prevent permanent vision damage or even blindness. 

The following guide can help determine if flashes and floaters are serious or not.

Triage Guide

Not urgent and likely benign vitreous floaters

These symptoms are often associated with normal vitreous aging, although new floaters still warrant being checked out by your eye doctor.

• A few floaters that have been present for a long time
• Floaters that change slowly over months or years
• The occasional flashing light, probably noticed more in the dark, and that has already been diagnosed as normal for you

What to do:

Longstanding and unchanged floaters usually don’t require any special treatment. You might want to mention them at your next routine eye appointment.

Urgent Warning Signs: Possible Retinal Tear

Some of all of the following symptoms could potentially be indicative of a retinal tear. They need same-day evaluation:

• A sudden shower of new floaters
• New flashing lights, especially in one eye
• A sudden increase in existing floaters
• A ring of floaters or many tiny black spots
• Blurred vision that appeared suddenly

What to do:

At a very minimum you should call an eye doctor immediately for urgent same-day assistance. If you can’t get hold of an eye specialist promptly, go to the ER the same day, especially if symptoms are worsening.

Emergency Warning Signs: Possible Retinal Detachment

Any of the above symptoms, plus one or more of the following, suggest the retina may already be detaching:

• A dark curtain or shadow moving across your vision
• Missing side vision
• A gray veil over part of what you see
• Sudden, significant vision loss
• Symptoms getting worse over hours or days

What to do:

Experiencing some or all of these symptoms is an eye emergency. DO NOT wait for a routine appointment. Go straight to an eye clinic that offers emergency care or, failing that, straight to the ER. Ideally, someone else should drive you. 

Who Is at Higher Risk? 

Some people are more likely to develop retinal tears or detachments, although it can happen to anyone. Risk factors include:

• Having significant nearsightedness (myopia)
• Aged 40+
• Previous eye surgery, especially cataract or glaucoma surgery
• Previous retinal tear or detachment in either eye
• Eye injury or trauma
• A family history of retinal detachment
• Having diabetic eye disease

However, whether or not you have any of these risk factors, the appearance of new floaters and flashes should always be taken seriously.

Red-Flag Symptoms (call vs. ER/emergency ophthalmologist visit)

All of the following are red flag symptoms that require emergency help. These warrant physically presenting for emergency care, rather than a phone call.

• Shower of new floaters
• Flashing lights
• Dark curtain or shadow in vision
• Sudden decrease in vision
• Loss of peripheral (side) vision
• Rapid worsening of floaters and/or other symptoms
• New symptoms affecting only one eye
• Gray veil, blank spot, or missing area in vision

These symptoms may indicate a retinal tear or retinal detachment and should not be ignored.

What Will the Doctor Do?

Whether you call or attend in person, the doctor will want to know when the symptoms started, whether they involve one or both eyes, and whether you have lost any vision. Clear, concise information helps — especially over the phone when the doctor will be making decisions dependent on what you say.

With eyesight, it’s always better to err on the side of caution. This includes reporting new floaters to an ophthalmologist, as it will always raise the suspicion of a retinal issue. A retinal eye exam, which allows the eye doctor to visualize the back of the eye, is key. Remember, prompt treatment is vital. An early diagnosed tear is far more easily treated, often by laser, than the more intricate surgery required for a retinal detachment.

While floaters and the occasional flash can be and are often normal for most people, sudden changes of any kind should be taken seriously. Anyone of any age can experience a retinal tear or detachment. If any red flag symptoms are present, seek immediate emergency help. 

Experiencing a sudden change in floaters or flashing lights? Call the West Boca Eye Center immediately.

A triage guide to floaters and flashes -- when they're harmless, when they signal a retinal tear, and when to seek emergency care to protect your vision.

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