Flashes and floaters

Floaters are small dots, lines, or ‘cobwebs’ that appear in your field of vision. These often move around, and will be more obvious at certain times such as against a blank background. Floaters are due to clumps of gel or cells moving around inside the eye – ‘floating’ in the vitreous gel.

Flashes are small flashes of light, often appearing at the outside edge of the peripheral vision. They may look like a camera flash or arc of light. Flashes are due to abnormal stimulation of the retina, such as pulling from the vitreous gel.

Posterior vitreous detachment (PVD)

As we age, the vitreous gel that fills the back of the eye becomes more liquid and loses its structure, starting to ‘swish around’ inside the eye. This is due to the collagen becoming weaker, like forming wrinkles on the skin.

When a large clump of the vitreous gel pulls away from the back of the eye, you may notice a sudden large floater, many small floaters, or flashes. This process is known as a posterior vitreous detachment (PVD). A PVD may happen earlier when you are short-sighted (myopia), have had cataract surgery, or eye trauma.

The retina (the ‘film’ of the camera) is like a wallpaper on the back wall of the eye. As the vitreous gel moves inside the eye it can tear or pull off the wallpaper. This is known as a retinal tear or a retinal detachment. This may be associated with bleeding inside the eye, a vitreous haemorrhage. These problems can lead to permanent loss of vision.

Diagnosis

If you have any of the warning symptoms above, you should have an urgent eye examination (same day or next day) with your local optometrist or ophthalmologist.

For the examination you will have drops to dilate your pupils. These will blur your vision and increase light sensitivity for about half a day. You will not be able to drive yourself home from the appointment.

Treatment

Posterior Vitreous Detachment (PVD)

If your dilated retina exam is normal, you may have just had the natural aging of the gel (a ‘PVD’) - no treatment is required.

However, the whole gel does not pull away from the back of the eye in one go – you could still form a retinal break or detachment at any stage after your initial examination. Remember the warning symptoms above and seek an urgent review if required.

Even if your symptoms remain stable or improve, a follow up dilated exam is recommended.

Flashes and floaters may persist for months or even years, but usually fade over time. Avoid focusing on the floaters as much as possible, to allow your brain to adapt.

Surgery to remove severe floaters is rarely required.

Retinal break

A retinal break (‘tear’ or ‘hole’) requires laser treatment to decrease the risk of retinal detachment. Retinal laser is performed sitting at a microscope in the clinic, and usually only takes a few minutes.

Retinal detachment

A retinal detachment requires surgery to fix. This is typically vitrectomy (keyhole surgery), though for certain types of detachment scleral buckle (band around the eye) is the best option.

If you have had any of these problems in one eye, there is an increased chance of the same thing happening to the other eye.

Keep those warning symptoms in mind, and arrange an urgent check if needed.

Medical disclaimer: This content is general in nature and intended only for patients of Dr Bennett. It is not to be taken as independent medical advice. All readers of this content must consult their own eye care professional. The authors of this content are not responsible for any harm that may arise in relation to the information presented here.