Most floaters and flashes are harmless age-related changes inside the eye and are not a cause for alarm. You should act quickly and seek same-day assessment when they come on suddenly, especially a shower of new floaters, persistent flashes, or a dark shadow or curtain across your vision, because these can signal a retinal tear or detachment.
- Understanding why they happen is helpful. The gel inside your eye can cast tiny shadows or pull on your retina to create flashes, which is completely normal and very common after the age of 45.
- Knowing what to watch for is key. Always ask yourself if your symptoms are new or suddenly worse, because a sudden change is much more important than the everyday floaters you are used to.
- Acting fast matters because if a tear is caught early, it can usually be treated before it causes major damage. This is why you need a same-day appointment instead of waiting.
- Getting a professional examination is the only way to tell them apart, because a harmless change and a dangerous tear can cause the same symptoms.
This article explains what floaters and flashes are, the common harmless causes, and the symptoms that mean you should be assessed without delay. If your symptoms have come on suddenly, please read the urgent section below first, then arrange an assessment straight away.
What Floaters and Flashes Actually Are
Floaters are small shapes that drift across your field of vision, such as dots, strands, cobwebs, or faint shadows. They are caused by tiny clumps within the vitreous, the clear gel that fills the eye. As light passes through, these clumps cast small shadows on the retina at the back of the eye, and you see them as floaters.
Floaters tend to move when you move your eyes, and they often dart away when you try to look at them directly. They are usually most noticeable against a bright, plain background, such as a clear sky or a white wall.
Flashes of light, known medically as photopsia, are brief sparks or streaks of light, often seen towards the edge of your vision. They may look like a camera flash or a flicker of lightning, and they tend to be more obvious in dim surroundings. Flashes happen when the gel inside the eye tugs on the retina, which responds by sending a brief light signal to the brain.
The Common, Harmless Causes
Most floaters and flashes come from normal ageing of the eye, and most people develop some over their lifetime. The sections below explain the two everyday changes behind them.
How the Vitreous Changes With Age
The vitreous gel is firm and clear when we are young. Over time it becomes more watery and starts to shrink. As it does, small strands within it become more visible, which is why floaters often increase gradually from around the age of 45. This slow change is normal and rarely causes any harm.
Why a Posterior Vitreous Detachment Happens
Posterior vitreous detachment (PVD) is the most common cause of new floaters in adults over 50. It is the next stage of the shrinking described above: the gel gradually peels away from the retina at the back of the eye, a normal process that happens to most people at some stage.
As the gel separates, you may suddenly notice new floaters and sometimes brief flashes of light.
In most people a PVD settles on its own and causes no lasting harm. Even so, a new PVD should be assessed, because the separating gel can occasionally pull hard enough to damage the retina.
When Floaters and Flashes Are an Emergency
A retinal tear or detachment is signalled in only a small proportion of cases. The symptoms below warrant urgent assessment, ideally the same day.
Seek urgent assessment if you notice:
- A sudden large increase in floaters, especially a shower or cloud of new ones
- A flash of light that persists or keeps recurring
- A dark shadow, curtain, or veil across any part of your vision
- A sudden loss of central or side (peripheral) vision
These symptoms may point to a retinal tear or retinal detachment. Please contact us or your referring doctor without delay, and do not wait for a routine appointment.
A retinal tear can happen when the vitreous pulls away and catches the retina. If fluid then passes through the tear and lifts the retina away from the back of the eye, this becomes a retinal detachment. The shadow or curtain listed above is the classic warning sign that this is happening.
A retinal detachment is a medical emergency. Treatment that begins early can often be carried out before further vision is affected, which is why the timing of assessment matters so much. These warning symptoms are recognised by the Royal Australian and New Zealand College of Ophthalmologists as possible signs of a serious eye problem.
How to Tell Calm From Cause for Concern
The key signal is change, so it helps to match what you are seeing to how urgent it is likely to be. Use this as a simple guide.
| Situation | What it usually means | What to do |
|---|---|---|
| Floaters you have had for years, unchanged | Normal vitreous change | No action needed beyond routine eye checks |
| A few new floaters, no other symptoms | Often a developing PVD | Arrange an urgent assessment to rule out a tear |
| A sudden shower of floaters or new flashes | Possible retinal tear | Seek same-day assessment |
| A shadow or curtain over your vision | Possible retinal detachment | Treat as an emergency, seek care immediately |
Because the symptoms of a harmless PVD and a sight-threatening retinal tear can feel very similar, the only reliable way to tell them apart is an eye examination. If you are short-sighted, you have a slightly higher chance of retinal problems, so new symptoms deserve particular attention.
What a Floaters and Flashes Check Involves
Checking that your retina is healthy is the priority when you are assessed for new floaters or flashes. Your doctor will ask when your symptoms began and how they have changed, because that history helps guide the examination.
A typical assessment includes:
- A dilated retinal examination, where eye drops are used to widen the pupil so the retina and the vitreous can be examined in detail
- Imaging of the retina where this is clinically helpful, such as optical coherence tomography (OCT), a scan that gives a detailed cross-section of the retina
If no retinal tear is found, you will be given a clear explanation of your results, advice on the symptoms that should prompt you to return, and any monitoring you need. If a tear is found, treatment may involve a laser to seal the tear, or a referral for retinal surgery if a detachment has developed.
You can read more about how these conditions are managed in our retinal conditions hub and on our retinal surgery page. New patients can find out how to arrange care on our new patients page.
Do Floaters Ever Go Away?
Floaters become less noticeable for most people over time. The brain gradually learns to filter them out, and over weeks to months they often fade into the background, even though the clumps themselves remain in the eye. Floaters do not usually disappear completely, but they tend to bother you less.
The large majority of floaters need no treatment at all. Once a specialist has confirmed the retina is healthy, reassurance and monitoring are usually all that is required. A surgical procedure to remove floaters does exist, but it carries real risks and is reserved for exceptional cases after a careful specialist assessment.
When Should You Get Your Eyes Checked for Floaters
When the change is sudden, prompt assessment is the right course. That is the one thing to take from this article: floaters you have lived with rarely need action, but a sudden or changing symptom does.
Your eyes are assessed by our specialist ophthalmologists, and your surgeon will discuss what is realistic for your individual situation. If you would prefer to be referred, your GP or optometrist can arrange this.
This article is general information and is not a substitute for individual medical advice. Eastwood Eye Surgery is staffed by specialist ophthalmologists registered with AHPRA. This content has been reviewed by a specialist ophthalmologist. If you have sudden changes in your vision, please seek prompt assessment.