What are “Floaters”?
Have you ever noticed little faint shapes that drift aimlessly around your field of vision? Those are known as floaters. You may grow concerned over them every now and again, or you just might not have ever given them a second thought. Either way, in this article we’re going examine what floaters are, what causes them, and whether or not they pose any threat to our eyes.
What exactly are floaters?
Floaters are shapes that drift around in front of your eyes, but they can appear in different ways, notably:
- Long, squiggly strands
- Tiny black dots
- Small, shadowy dots
- Spots that are larger still, and cloud-like in appearance
You can have many small floaters meandering around your field of vision at any given time, or possibly one or two larger ones. The majority, though, are small and usually exit your field of vision quickly.
If you have ever seen a floater, you may have noticed that they always tend to shoot out towards the periphery of your vision when you attempt to focus on them. This is because floaters move when the eye moves, making them appear as if they are drifting.
Why do we get them?
Floaters occur when tiny bits of debris penetrate the eye’s vitreous humour, which is the clear jelly like substance that occupies the space in the middle of the eyeball between the lens and the retina – the light-sensitive layer of cells at the back of your eye.
However, it’s not actually the debris that you can see floating around your field of vision, but rather the shadows that the debris casts onto the retina. This is why floaters are particularly pronounced when one looks at a bright sky, a white computer screen or anything else which is likely to emit a bright light.
Who gets them?
Age impacts the risk of developing floaters, as the vitreous humour tends to become softer as a person gets older. As a result of this, strands of a protein called collagen within the vitreous humour may start to appear more visible. Consequently, floaters tend to be largely experienced by people over the age of 40, and are most common in those over the age of 60. Despite this, some younger people also develop floaters.
There are a few other groups who are more susceptible to developing floaters. Notably, floaters are more common in people who suffer from short-sightedness or diabetes. In other instances, floaters can be a result of other eye complications, such as:
- Cataract surgery
- An eye injury
- Uveitis – an inflammation of the eye
Are floaters a problem?
Whilst it can be annoying to see them floating around, they usually don’t pose any threat. However, in some cases, floaters can point towards other issues of various levels of severity.
- Posterior vitreous detachment
In certain instances, a sudden influx of floaters can be an indicator of posterior vitreous detachment (PVD), which occurs when the cortex (the outer layer of the vitreous humour that contains more collagen), begins to shrink away from the retina. Consequently, collagen can thicken and bits can clump together to form the shadows that we perceive to be floaters.
This is not a great cause for concern though, in the vast majority of cases, PVD will not lead to long term changes in your vision. Approximately three quarters of people over the age of 65 experience PVD.
People with PVD may also experience flashing lights. This happens when the outer layer of the vitreous humour pulls on the retina’s light-sensitive tissue, stimulating it and causing the brain to interpret it as a light signal.
- Retinal tears
PVD can cause retinal tears in a few cases. This happens when blood vessels in the retina burst and bleed into the vitreous humour as a result of the humour tugging on the retina. The red blood cells will form the debris, and will either appear as tiny dots or will have a smoke-like appearance. Eventually, within the course of a few months, the retina absorbs the blood and the floaters usually disappear.
Floaters and flashes don’t usually cause long-term visual impairment. However, anybody who experiences an increase in floaters or associated symptoms is advised to get their eyes examined by an optometrist, as sometimes retinal tears can lead to retinal detachment.
- Retinal detachment
Firstly, it’s important to point out that retinal detachment is extremely rare. It only affects about one person in every 10,000.1 It can occur when the retina separates from its layer of support tissue and if the retina is damaged it may lead to decreased vision or blindness.
Because the retina transforms light signals into electrical signals, which are fed through the optic nerve to the brain, any signals that the brain receives from a detached retina may be patchy or non-existent. In rare cases an increase of floaters can be an indicator of retinal detachment. If your retina is detached, you’ll usually experience bright flashing lights.
How can you avoid floaters?
Floaters are often part of the natural ageing process and so can’t necessarily be definitely avoided.
Treatments that clear your eyes of floaters
Occasionally, people are interested in undergoing surgery to remove eye floaters. However, because floaters are innocuous in the vast amount of cases, doctors are only willing to perform procedures in rare instances when vision is seriously affected. In which case, a vitrectomy procedure could be undertaken where the vitreous would be removed from the eye and then replaced with a saline liquid.
If you develop floaters, your optician or optometrist may ask that you monitor your condition and book you in for another appointment a couple of months later to make sure that your retina is still stable. From then on, you may be advised to undergo eye examinations a bit more frequently, just as a precaution, if symptoms worsen at any time, you should seek immediate advice.