Have you ever looked up at a clear blue sky or a blank white wall, only to see tiny, dark specks drifting across your vision? You try to blink them away, but they follow your gaze, darting off just as you try to focus on them.
It can be a disconcerting experience. These visual disturbances are widely known as eye floaters. While they are often described as looking like small flies, cobwebs, or squiggly lines, they are not actually external objects. They exist inside your eye.
For most people, noticing these floating shapes is a completely normal part of the ageing process. It is estimated that a significant portion of the population will experience them at some point in their lives. However, while usually harmless, they can occasionally signal a more serious underlying condition that requires immediate attention from an eye care professional.
Understanding the difference between a benign annoyance and a medical emergency is vital for protecting your vision. This guide breaks down exactly what creates these visual anomalies, identifying the specific symptoms you should never ignore, and outlining when it is time to book an appointment with your local optician.
What are eye floaters?
To understand floaters, we first need to look at the anatomy of the human eye. The largest part of your eye is filled with a clear, jelly-like substance called the vitreous humour. This substance helps maintain the eye’s round shape and allows light to pass through to the retina at the back of the eye.
When we are young, the vitreous humour is perfectly transparent and has a firm, gel-like consistency. However, as we age, this gel begins to change structure. It gradually liquefies and shrinks—a process known as syneresis.
During this process, the microscopic collagen fibres within the vitreous tend to clump together. These clumps or strands cast tiny shadows onto your retina, which is the light-sensitive tissue lining the back of your eye. What you perceive as a “floater” is actually the shadow of these protein clusters floating within the vitreous gel.
According to the NHS guide on eye health, these shadows are most noticeable when looking at a plain, bright background. Because the clumps are suspended in fluid, they move when your eyes move, creating that characteristic drifting motion.
The Role of Posterior Vitreous Detachment (PVD)
One of the most common causes of noticeable floaters in older adults is a condition called Posterior Vitreous Detachment (PVD). This occurs when the vitreous gel shrinks enough to pull away from the retina entirely.
While this sounds alarming, PVD is a very common occurrence, particularly for those over the age of 50. It usually happens without causing pain or permanent vision loss. However, the sudden appearance of new floaters is a hallmark sign of this separation occurring.
For a deeper dive into this specific mechanism, you can read more about Posterior Vitreous Detachment on Healthline, which explains the physiological changes in detail.
Symptoms and Shapes: What to look for
Eye floaters vary significantly in appearance from person to person. You might notice them in just one eye, or they may appear in both eyes simultaneously. They generally settle at the bottom of the eye below the line of sight but move up when you look up.
Common visual characteristics include:
- Black or grey dots: Often looking like pepper flakes.
- Squiggly lines: Resembling transparent worms or threads.
- Cobwebs: Irregular, mesh-like shapes.
- Rings: Sometimes called Weiss rings, which represent the piece of vitreous that was attached to the optic nerve.
Crucially, these shapes will never stay still. If you try to look directly at one, it will seem to run away. This is because the floater moves with the movement of your eye fluid.
Experts at Moorfields Eye Hospital suggest that while these shapes are annoying, your brain is remarkably adept at learning to ignore them over time—a process called neuro-adaptation.
When to visit your optician: Warning signs
Most of the time, floaters are a benign nuisance that does not require treatment. However, they can be a symptom of a retinal tear or retinal detachment. This is a medical emergency that can lead to permanent blindness if not treated surgically within hours or days.
It is imperative to distinguish between normal age-related changes and sight-threatening conditions. The Royal National Institute of Blind People (RNIB) highlights specific “red flag” symptoms that warrant an immediate visit to an optician or A&E department.
1. Sudden onset of new floaters
If you suddenly see a shower of spots or a significant increase in the number of floaters you normally see, do not wait. This sudden change suggests that the vitreous may be pulling on the retina with enough force to tear it.
2. Flashes of light (Photopsia)
Seeing flashes of light in your peripheral (side) vision is a critical warning sign. These flashes occur when the vitreous gel tugs on the retina, stimulating the photoreceptors physically rather than by light. It might look like a camera flash or a lightning streak.
3. A dark curtain or shadow
If a grey curtain, veil, or shadow appears to be moving across your field of vision (from the side, top, or bottom), this often indicates that the retina has detached and is losing function. This is an emergency.
4. Blurring of central vision
While floaters themselves can cause momentary blurring if they drift across your line of sight, persistent blurred vision suggests more extensive damage to the eye structure or inflammation.
Risk Factors for complications
Certain individuals are at higher risk of developing complications associated with floaters. According to the College of Optometrists, you should be extra vigilant if you:
- Are very short-sighted (high myopia).
- Have had recent eye surgery (such as cataract surgery).
- Have suffered trauma to the eye.
- Have a history of eye inflammation (uveitis).
Comparison: Harmless vs. Emergency
The following table outlines the key differences between typical benign floaters and symptoms that require urgent medical intervention.
| Feature | Benign Floaters | Potential Retinal Emergency |
|---|---|---|
| Onset | Gradual appearance over months or years. | Sudden, dramatic appearance of many floaters. |
| Flashes | Rarely accompanied by flashing lights. | Frequent bright flashes (like lightning) in side vision. |
| Vision Loss | No loss of peripheral vision. | Dark curtain or shadow blocking part of vision. |
| Duration | Constant but often ignored by the brain. | Persistent and worsening rapidly. |
| Pain | Painless. | Usually painless, but vision changes are drastic. |
Causes beyond ageing
While age-related changes to the vitreous humour are the primary culprit, other health conditions can manifest as floaters. It is important to consider your overall health when assessing eye symptoms.
Inflammation (Uveitis)
Posterior uveitis is inflammation in the layers of the eye. This condition can release inflammatory debris into the vitreous, which is perceived as floaters. The National Eye Institute notes that this is often accompanied by light sensitivity and redness.
Diabetic Retinopathy
For individuals with diabetes, blood vessels in the retina can become damaged and leak blood into the vitreous humour. Even small amounts of blood can appear as dark floaters. Diabetes UK emphasises that regular screening is essential to catch this early.
Eye Surgeries and Medications
Some medications injected into the vitreous can cause air bubbles, which are seen as shadows until the eye absorbs them. Similarly, silicone oil bubbles used in certain retinal surgeries can appear as floaters.
Frequently Asked Questions
Do eye floaters ever go away?
Generally, floaters do not fully disappear. However, they tend to settle at the bottom of the eye over time, becoming less visible. Furthermore, your brain learns to filter them out. If they become extremely dense and obscure vision, surgery (vitrectomy) is an option, though it carries risks.
Can eye exercises reduce floaters?
No. Moving your eyes can shift the fluid and temporarily move a floater out of your direct line of sight, but no amount of exercise will dissolve the collagen clumps.
Does diet affect eye floaters?
There is no scientific evidence that specific foods or supplements can cure floaters. However, a diet rich in antioxidants, leafy greens, and omega-3 fatty acids supports overall eye health. The Macular Society provides excellent guidance on nutrition for vision.
Is it safe to drive with floaters?
Usually, yes. Unless the floaters are so dense that they obscure your view of the road, they do not prevent you from driving. However, if you experience sudden flashes or a curtain effect, you must not drive and should seek help immediately. Always check GOV.UK for DVLA standards regarding vision requirements.
Why do I see them more on bright days?
Floaters are shadows. When you look at a bright, uniform background like a sunny sky or a white computer screen, your pupil constricts (gets smaller). This creates a sharper aperture, making the shadows cast by the floaters on your retina more defined and obvious.
The Bottom Line
For the vast majority of people, eye floaters are a harmless, albeit annoying, consequence of getting older. They are simply clumps of protein casting shadows inside your eye. Most people eventually stop noticing them as the brain adapts to the visual noise.
However, you must remain vigilant regarding sudden changes. If you experience a sudden shower of new floaters, flashing lights, or a loss of peripheral vision, these are warning signs of a retinal tear or detachment. In these cases, time is vision.
Prioritise your eye health by maintaining regular check-ups. As noted by the Association of Optometrists, an optometrist can easily examine the back of your eye to confirm if your floaters are harmless or if treatment is required. When in doubt, always get it checked out.
