Flashes and Floaters — Urgent Assessment in Birmingham

Floaters appear as small black dots, cobwebs, strands or tiny specks drifting across your vision. They are often more noticeable when looking at a bright sky, a white wall or a computer screen.

Flashes are brief flickers or streaks of light, usually seen in your side (peripheral) vision. Many people describe them as lightning flashes or camera flashes occurring inside the eye.

Although most flashes and floaters are harmless, a sudden increase in symptoms should never be ignored.

Download our Flashes and Floaters patient leaflet

Why do flashes and floaters occur?

Inside the eye is a clear jelly-like substance called the vitreous.

As we get older, the vitreous naturally becomes more liquid and slowly shrinks. During this process it can separate from the retina at the back of the eye. This is called a Posterior Vitreous Detachment (PVD).

As the vitreous moves away from the retina it may:

• cast tiny shadows that appear as floaters
• gently pull on the retina, producing flashes of light

For most people this is a completely normal ageing change. However, in a small number of patients, the pulling can create a retinal tear which may progress to a retinal detachment if left untreated.

What is a Posterior Vitreous Detachment (PVD)?

A Posterior Vitreous Detachment is one of the commonest causes of new flashes and floaters. It simply means that the vitreous gel has separated from the retina.

Although this sounds alarming, a PVD is usually harmless and often requires no treatment.

The important point is that every new PVD should be examined carefully because approximately 10–15% of symptomatic PVDs are associated with a retinal tear, particularly when flashes are accompanied by numerous new floaters or vitreous haemorrhage.

This is why a specialist retinal examination by Mr Don Williams is so important.

What happens after a PVD is diagnosed?

If your examination confirms a straightforward PVD, you will usually be re-examined a few weeks later, because a small number of retinal tears develop after the initial symptoms rather than with them. 

Between appointments, the warning signs to return urgently for are the same: a sudden shower of new floaters, a marked increase in flashes, or any shadow or curtain in your vision.

Flashes typically settle as the vitreous completes its separation, and floaters become less noticeable over the following months.

Why do floaters move?

Many patients ask why floaters seem to drift away whenever they try to look directly at them. The answer is simple.

Floaters are suspended within the vitreous gel. When your eyes move, the vitreous moves slightly behind the movement of the eye, causing the floaters to drift across your vision before gradually settling again.

Over time, many people become less aware of their floaters because the brain gradually adapts and begins to ignore them.

Are flashes and floaters always dangerous?

Fortunately, no. Most flashes and floaters are caused by normal age-related changes inside the eye.

However, they can sometimes indicate more serious conditions including:

• Retinal tears
• Retinal detachment
• Vitreous haemorrhage
• Retinal inflammation (uveitis)
• Diabetic eye disease

Because it is impossible to know the cause without examining the retina, any sudden onset of flashes or floaters should be assessed promptly.

Who is more likely to develop flashes and floaters?

Certain people have a higher risk of developing vitreous changes and retinal problems. These include patients who:

• are over 50 years of age
• are short-sighted (myopic)
• have diabetes
• have previously undergone cataract surgery
• have experienced eye trauma
• have previously had a retinal tear or retinal detachment
• have a family history of retinal detachment

What happens during a flashes and floaters examination?

At Edgbaston Eye Clinic, your assessment is designed to identify the exact cause of your symptoms. Depending on your clinical findings, your examination may include:

• Comprehensive ophthalmic assessment
• Vision testing
• Eye pressure measurement
• Dilated retinal examination
• Slit-lamp biomicroscopy
• Optos Daytona ultra-widefield retinal imaging
• Optical Coherence Tomography (OCT)

The combination of advanced imaging and careful clinical examination allows us to assess the retina, vitreous and optic nerve in exceptional detail.