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HealthInfo Canterbury


Visual floaters are blobs, thread-like strands, fine cobwebs, or just dull shadows and spots in your vision. They are more noticeable when you look at a white wall or plain, light-coloured surface such as the sky.

Floaters are actually particles within the vitreous fluid, the clear gel-like substance that fills the inside of your eyeball. These particles cast shadows on the retina, the light-sensitive layer at the back of your eye. As you get older, floaters become more common.

Floaters are relatively common and usually harmless.

Causes of floaters

Floaters can be a sign of something more serious.

Posterior vitreous detachment (PVD)

This is when the gel-like vitreous fluid, which is normally attached to the retina at the back of your eye, separates from the retina.

Most people with posterior vitreous detachment simply have floaters, which can be a nuisance but usually settle over a few months. However, occasionally it can happen with, or lead to, a retinal detachment.

Retinal detachment is painless, but it is a medical emergency as it can cause blindness unless treated immediately. For this reason, posterior vitreous detachment always needs to be assessed, to make sure it isn't causing, or happening with, retinal detachment.

If you have new floaters or flashes, it's best to get your eyes checked immediately (today) to look for any sign of retinal detachment.

Vitreous haemorrhage

This is when a tiny blood vessel in the retina bursts and leaks blood into the gel-like vitreous, causing the sudden appearance of floaters. Sometimes this just causes small floaters that don't need treatment. Other times, the floaters may be large enough to affect your vision, and you will need surgery. It can also be a sign of eye damage caused by diabetes. Get your eyes checked to find out what has caused this.


See your optometrist, ophthalmologist or GP today if you have any of the four Fs.

You need to have these assessed urgently – on the same day. Over the weekend you can be assessed at an after-hours GP clinic and they can refer you to an ophthalmologist urgently if necessary.

You are likely to need drops to make your pupils larger so there is a better view into your eye. If possible bring someone with you who can drive you home again while the drops wear off.

On the next page: Flashes and retinal detachment

Written by Canterbury optometrists. Adapted by HealthInfo clinical advisers. Endorsed by clinical director, Ophthalmology, Canterbury DHB. Last reviewed November 2019.


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Review key: HIFFRT-139694