Floaters appear as black spots or strands that look like a hair or small pieces of cobweb. These can be semi-transparent or dark and appear to float in your vision. Sometimes they may appear more noticeable than others. If you have had these for years, your eye and your brain learn to ignore them. Sometimes the number of floaters increases as you get older. Occasionally an increase in floaters can be a sign of problems inside the eye.
Because they ‘float’ in the gel of your eye, floaters will move away in the direction you move your eye when you try to look at them. Although floaters are very small, you can see them because they cast a shadow on the retina. You might only see floaters if you are staring at a light coloured surface or at the sky during the day.
Some people find that floaters can be a nuisance, but most people get used to them. They rarely cause problems with your vision.
Some people are born with floaters but most floaters develop as you get older, when the gel in your eye naturally shrinks. The gel separates into watery fluid and wavy collagen strands (fibrils). The fibrils are seen as line-shaped floaters. Sometimes the gel shrinks enough to collapse away from the light-sensitive lining at the back of your eye (the retina). Once the gel has collapsed, you may see a large ring-shaped floater. As the vitreous gel collapses it can pull on your retina. If this were to happen, you would see it as a flash of light.
Floaters can also be caused by some eye conditions that cause inflammation. This is not very common.
Floaters are more common in people who are short-sighted. They may increase if you have had an eye operation such as cataract surgery, or laser treatment after cataract surgery. They are also more likely if you have a history of eye injury, infection or inflammation.
Most of the time floaters are harmless. Sometimes they may be annoying, but treatment is not usually advised.
A sudden increase in floaters – either one or more large ones or a shower of tiny ones – may be a sign of a more serious eye condition such as a retinal detachment. This is when your retina pulls away from the back of your eye. This may lead to a blank spot or shadow in your vision which does not go away.
If you notice these symptoms, you should contact your optometrist straight away. If you can’t do this, you should get urgent medical attention from an eye casualty department at a hospital. If you are unable to attend eye casualty nearby, you can go to your local accident and emergency department (A&E). An ophthalmologist or an optometrist will use eye drops and a special microscope to look inside your eyes to check if your retina is damaged.
When we are young, the vitreous gel is firmly attached to the back of our eye. As we get older, the vitreous gel naturally becomes more liquid, so it shrinks and collapses away from the retina. This means the gel can move inside the eye. This is called a posterior vitreous detachment (PVD). It is very common and more likely to happen as you get older. If you get a PVD you may see flashes of light in front of one of your eyes. These appear like small sparkles, lightning or fireworks as the gel touches or tugs the retina.
The flashes tend to be in the extreme corners of your vision and come and go but don’t obscure any part of your vision. The flashes don’t last for a set length of time, and you may notice them more if you go from a light to dark environment. They may continue on and off for weeks or months. These are different to the shimmering or zig-zag lines that may be part of a migraine.
If you notice these symptoms, you should contact your optometrist straight away. You can also get flashes after being hit in your eye or if you rub your eyes roughly.
Sometimes flashes just show that the vitreous gel is tugging on your retina. However, constant flashes may be a sign of a retinal detachment.
A torn retina or retinal detachment may lead to a sudden increase in floaters as well as flashes. You might also notice a shadow at the edge of your vision. This needs immediate medical attention.
If you notice these symptoms, you should contact your optometrist straight away. If you can’t do this, you should get urgent medical attention from an eye casualty department at a hospital. If there is no eye casualty department nearby, you can go to your local accident and emergency department (A&E). An ophthalmologist or an optometrist will use eye drops and a special microscope to look inside your eyes to check if your retina is damaged.
You may be more at risk of a retinal detachment if you:
Watch our video to find out more about flashes and floaters:
Watch our video to find out what it’s like to have floaters:
Last reviewed: November 2024
