Floaters are shadows cast inside your eye
Your eye is filled with a clear, gel-like substance called the vitreous humour. This gel sits between the lens at the front and the retina at the back. As we age, the gel gradually shrinks and becomes more watery. As this happens, tiny clumps of protein and fibre form within it.
These clumps cast small shadows onto the retina. The retina is the light-sensitive layer at the back of the eye that sends visual information to the brain. The shadows are what you perceive as floaters, they can appear as dots, threads, cobwebs, or wispy shapes that drift across your field of vision.
Floaters move with your eye because they are suspended in the vitreous gel. They tend to drift slowly when your eye is still, and are most visible against a plain bright background, a clear sky, a white wall, or a brightly lit screen.
Floaters are very common, and become more so with age
Floaters are one of the most common reasons people visit an eye clinic. The vast majority of people will develop them at some point during their lifetime, and they become increasingly common from the age of 40 onwards.
People who are short-sighted (myopic) tend to develop floaters earlier, because their eyes are slightly longer and the vitreous gel changes sooner. Floaters are also more common after eye surgery, and following inflammation inside the eye.
In most cases, no specific cause is found. The floaters are simply the result of normal, age-related changes in the vitreous gel, not a sign that anything is wrong.
If you have floaters that have been present for a long time, have not changed, and are not accompanied by any other symptoms, there is almost certainly nothing to worry about.
Floaters are most visible in certain conditions
Floaters can seem to come and go depending on where you are and what you are looking at. This is normal, and it does not mean that the floaters are getting worse.
You are most likely to notice floaters when you look at a uniform, bright surface, a pale sky, a white ceiling, or a well-lit page. In complex visual environments, such as a busy street or a room full of objects, the brain tends to filter them out.
Floaters also appear more noticeable when you are tired or stressed. This is because you tend to focus on them more. The brain is very good at adapting to floaters over time, and many people stop noticing them entirely after a few weeks or months.
For a more detailed explanation of how floaters form, read: Eye floaters explained.
Most floaters are caused by normal changes in the vitreous gel
The most common cause of new floaters in adults is a posterior vitreous detachment, or PVD. This is when the vitreous gel separates from the retina at the back of the eye. It sounds alarming, but it is a natural, age-related process that happens to almost everyone eventually.
When the gel separates, it often causes a noticeable increase in floaters, sometimes a sudden shower of new ones, and may also cause brief flashes of light. The flashes happen because the separating gel pulls on the retina before letting go. Once the detachment is complete, the flashes usually settle.
A PVD is not dangerous in itself, but it does need to be assessed to confirm that no damage has occurred to the retina during the process. This is why new floaters and flashes should always be checked promptly by an eye professional.
Less commonly, floaters can be caused by bleeding into the vitreous, inflammation, or, rarely, a retinal tear or detachment. These causes are important to exclude, which is why any sudden change in floaters deserves proper assessment.
Some changes in floaters need prompt attention
Most floaters that have been present for a long time without changing are harmless. What changes the picture is when floaters appear suddenly, especially in large numbers, or when they are accompanied by other symptoms.
The vitreous gel can, as it changes, place traction on the retina. In most cases this resolves without causing harm. But occasionally, this traction causes a small tear in the retina. If undetected and untreated, a retinal tear can progress to a retinal detachment, a serious condition that threatens sight.
This is why the warning signs matter. They do not mean that something serious has happened, but they mean the eye needs to be examined to find out.
- Sudden increase in floaters
- Flashes of light
- A dark shadow or curtain in the vision
- Any loss of vision
If you are unsure whether your symptoms need urgent attention, use the tool below to help guide you.
Not sure if your symptoms are serious? When to worry about floaters explains this in more detail.
When to seek same-day attention
If you notice a sudden shower of new floaters, flashes of light, a shadow in your vision, or any loss of vision, you should contact an eye casualty department or optometrist the same day. Do not wait to see if things settle on their own.
The good news is that when patients are seen promptly, the examination is reassuring in the majority of cases. If a retinal tear is found, it can usually be treated quickly and very effectively with a simple laser procedure. The outcome is almost always excellent when it is caught early.
If these symptoms are present, the eye needs to be examined promptly. In most cases the examination is reassuring, but it is important not to delay.
Use the floaters tool to help guide your next step.
The overwhelming majority of floaters are completely harmless
Floaters are seen in eye clinics every single day. In the vast majority of cases, the examination is entirely normal, no treatment is needed, and patients leave with a clear and reassuring answer.
Most people who develop floaters find that they become less noticeable over time. The brain adapts remarkably well. Within a few weeks or months, most people stop being aware of their floaters in everyday life, even if the floaters themselves are still technically present.
In summary
- Floaters are very common and usually harmless
- They are caused by normal, age-related changes in the vitreous gel
- Most people's brains adapt to them and stop noticing them
- Sudden new floaters, flashes of light, or any shadow in the vision need same-day assessment
- When seen promptly, the examination is reassuring in the majority of cases
Frequently asked questions
Are floaters normal with age?
Yes. Floaters are a normal part of how the eye ages. They become increasingly common from the age of 40 onwards, and almost everyone will develop some degree of floaters during their lifetime. They are caused by natural changes in the vitreous gel inside the eye, and in the great majority of cases they are entirely harmless.
Can floaters go away?
Floaters do not usually disappear completely, but they often become far less noticeable over time. The brain adapts remarkably well, and many people stop being aware of their floaters within a few weeks or months, even if the floaters themselves are still physically present. In some cases, floaters do become smaller and less dense as the vitreous gel settles.
Why do I see floaters in bright light?
Floaters are most visible against a bright, uniform background, such as a clear sky, a white wall, or a brightly lit screen. This is because the contrast between the shadow of the floater and the bright background makes the shadow more apparent. In complex visual environments, the brain tends to filter floaters out, which is why you may not notice them at all in some settings.
Are flashes of light normal?
Brief flashes of light can occur when the vitreous gel pulls on the retina, which often happens during a posterior vitreous detachment (PVD), a common, age-related change. These flashes are usually short-lived and settle once the gel has fully separated. However, new or persistent flashes of light should always be assessed by an eye professional the same day, as they can occasionally indicate a retinal tear.
Do I need to see a doctor about floaters?
If your floaters are long-standing, have not changed, and you have no other symptoms, you do not necessarily need an urgent appointment. It is always reasonable to mention them at a routine eye examination. If your floaters are new, appeared suddenly, or are accompanied by flashes of light or any change to your vision, you should be seen the same day. When in doubt, it is always better to be examined than to wait.
Last medically reviewed: May 2026
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