A tiny speck drifting across your vision can be distracting enough. A sudden shower of new dots, cobweb-like strands or flashes of light at the edge of your sight can feel far more worrying. Floaters and flashes are common, particularly as we get older, and are often linked to normal changes inside the eye. However, a new or sudden change should never be ignored, because it can occasionally signal a problem that needs prompt treatment.
The reassuring part is that a thorough eye examination can establish what is happening and whether your retina is healthy. The key is knowing when to arrange an appointment and when to seek urgent help.
What are floaters and flashes?
Floaters are small shapes that appear to move through your field of vision. People describe them as dots, squiggly lines, threads, rings, cobwebs or tiny flies. They are most noticeable against a pale background, such as a bright sky, a white wall or a computer screen.
They are not usually objects sitting on the surface of the eye. Instead, they are shadows cast on the retina, the light-sensitive layer at the back of the eye. These shadows are caused by tiny clumps or strands within the vitreous, the clear gel that fills the centre of the eye.
Flashes are different. They may look like brief flickers, sparks, lightning streaks or camera flashes, often seen at the side of vision. They can occur when the vitreous gel tugs on the retina. Some people notice them more in dim light or when moving their eyes.
Occasional longstanding floaters, especially if they have not changed, are usually not a cause for alarm. But your individual circumstances matter. A new floater in one eye, for example, deserves different attention from a familiar speck you have noticed for years.
Why do floaters and flashes happen?
The most frequent explanation is a posterior vitreous detachment, often shortened to PVD. Despite the name, this is commonly a normal age-related change. Over time, the vitreous becomes more liquid and can separate from the retina. It may create new floaters and sometimes flashes while the separation is taking place.
A PVD becomes more common from middle age onwards, although it can happen earlier in people who are short-sighted, have had eye surgery, have experienced an eye injury or have a family history of retinal problems. It can also occur without an obvious reason.
In many cases, the symptoms gradually become less noticeable. The brain often learns to filter out floaters, while some settle below the central line of sight. There is no reliable home treatment to make them disappear, and trying to ignore a sudden onset without an eye assessment is not the right approach.
Flashes can also be associated with migraine, particularly visual migraine. These visual effects often appear as shimmering zigzags or patterned lights, may affect both eyes, and tend to build and resolve over a short period. A migraine aura is not the same as flashes from vitreous traction, so a first episode or an unfamiliar visual disturbance should still be discussed with an eye care professional.
When a sudden change needs urgent attention
Most new floaters and flashes are not caused by a retinal tear or retinal detachment, but an examination is needed to tell the difference. Occasionally, as the vitreous pulls away, it can tug hard enough to create a tear in the retina. Fluid can then pass through the tear and lift the retina away from the back of the eye.
Retinal detachment is time-sensitive. Early assessment gives the best opportunity to protect vision, which is why it is sensible to act promptly rather than wait to see whether symptoms settle.
Arrange urgent eye care on the same day if you notice any of the following:
- a sudden burst or marked increase in floaters, particularly dark dots, threads or a shower of spots
- repeated new flashes, especially in one eye or at the edge of your vision
- a dark curtain, veil or shadow moving across your sight
- missing areas of vision, blurred vision or a noticeable reduction in vision
- floaters or flashes after a blow to the eye, head injury or recent eye surgery
If you cannot access an urgent optometry appointment, contact NHS 111 for advice on the appropriate local service. If your vision is suddenly and severely affected, seek emergency medical help. Do not drive yourself if your vision is impaired.
It is also worth arranging a prompt examination if you have had symptoms before but they have changed, or if you are highly short-sighted. The same applies if you have previously had a retinal tear or detachment in either eye.
What happens at an urgent eye examination?
An urgent assessment is designed to give you clarity, not simply reassurance. Your optometrist will ask when the symptoms began, whether they are getting worse, and whether you have noticed a curtain, blurred vision or pain. They will also consider your prescription, medical history and any previous eye treatment.
Your vision and eye pressure may be checked, followed by a close examination of the retina. Dilating drops are often used to widen the pupil, allowing a much better view of the back of the eye, including the far peripheral retina where tears can occur.
These drops can make your vision blurry and more sensitive to light for several hours. It is usually best to avoid driving afterwards, so plan accordingly if possible. If the examination identifies a retinal tear, you may be referred urgently to the hospital eye service for treatment. If the retina is healthy, you will be advised about what changes to watch for and whether follow-up is appropriate.
This is where continuity of care can be particularly valuable. Having a team that knows your eye history and takes time to explain the findings can make a frightening visual symptom feel much more manageable.
Can floaters be treated?
For most people, treatment is not needed. Once a retinal problem has been ruled out, the safest approach is usually to allow time for the symptoms to become less intrusive. Floaters may remain visible, but many people find that they bother them far less after the first few weeks or months.
There are surgical and laser-based treatments for selected cases, but they are not routine solutions for ordinary floaters. Any procedure inside or around the eye carries potential risks, including retinal complications, cataract development or changes in eye pressure. The decision depends on how severely symptoms affect daily life, the type and position of the floaters, and the overall health of the eye.
A careful discussion is more useful than a one-size-fits-all answer. If floaters are making reading, screen work or driving difficult, mention this during your appointment. Your optometrist can help you understand whether monitoring, practical adjustments or referral for further opinion is appropriate.
Looking after your eyes between appointments
There is no proven vitamin, eye drop or exercise that prevents ordinary age-related floaters. General eye health still matters, of course: attend regular eye examinations, wear appropriate eye protection for work and sport, and keep glasses or contact lens prescriptions up to date.
If you spend long hours at a screen, reducing glare and taking regular visual breaks can make your eyes feel more comfortable, but it will not remove true floaters. It is also helpful to remember that dry eye, screen fatigue and floaters can occur at the same time, yet they have different causes and need different advice.
The most useful action is simple: become familiar with your normal vision. If floaters and flashes are new, suddenly worse or accompanied by a shadow or loss of sight, arrange urgent assessment. A prompt, unhurried eye examination can protect more than your peace of mind – it can protect your vision.