Anyone can suffer from eye flashes and floaters, but they are more common in older people, people who are short-sighted and in people who have had eye surgery.

What are Floaters?

Floaters appear as grey or black specs, lines, or ‘cobwebs’ in front of the eyes. As the eyes move, the floaters move too. They do not follow your eye movements precisely, as they usually drift when the eyes start or stop moving.

Floaters are caused by clumps or bits of material suspended in the vitreous jelly that fills the back of the eye. The floaters cast shadows on the light sensitive retina. It is actually the shadow of the floater that you see. Floaters may have a variety of causes, some serious, and some not serious at all.

What are Flashes?

Flashes are sensations of light, when no light is really there. They may appear as many tiny bright lights (like ‘sparklers’) or like flashes of lightening. Flashes may occur when the vitreous jelly pulls on or tears the retina. These flashes usually last for only a second or so, but typically occur repeatedly.

They may be more obvious with eye movement, or in a dark room. Some people with migraines may experience a different type of flash. These are usually shimmering, jagged lights that are present constantly for a period of fifteen minutes or so. They typically appear in the centre of your field of vision, and progress slowly towards the edges of the visual field.

A headache that is commonly throbbing, and on one side of the head, may follow the disappearance of the flashes.

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Warning Signs

Floaters are very common and normally harmless, some people notice they see flashes of light.

However occasionally, flashes or an increase in floaters can be indicative of a more serious condition, even retinal detachment – which needs treating as soon as possible.

The most serious warning sign is:

  • A shadow or curtain that spreads across one of your eyes

Seek medical attention from Eye Casualty ASAP:

Nottingham QMC
Eye Casualty

0115 924 9924 ext. 42882

Leicester Royal Infirmary
Eye Casualty

0116 254 1414

If you have any of these other symptoms:
  • See a sudden shower of floaters across your vision
  • A new large floater
  • Floaters combined with flashes of light

These are less serious but should still be examination thoroughly. Book an appointment with a trusted optometrist.

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What is the Vitreous?

The vitreous is a jelly like material that fills most of the space inside the eye. As we age, the vitreous often liquefies and may collapse. This is more likely to occur, and occurs much earlier, in the eyes that are nearsighted (myopia). It can also occur after injuries to the eye or inflammation in the eye.

What is the Retina?

The retina is a thin sheet of light sensitive nerve tissue that lines the inside of the eye. It is the tissue that turns light into an electrical signal to send to the brain. It can be compared to the film of a camera

See More In Our Eyecare Glossary

What can my Optometrist do about Flashes and Floaters?

Anyone with flashes or the sudden onset of a new floater (or floaters) should be examined promptly by an ophthalmologist/Optometrist. We will perform a dilated fundus exam – looking at the vitreous and retina with specialised equipment after giving drops to enlarge the pupils.

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In most people*, these drops have a temporary effect on vision, but you will not be able to drive afterwards. The effect of the drops will wear off within a few hours.

Usually we can rule out any serious problems, flashes normally settle down after a few days or weeks without treatment.

Floaters may be longer lasting, but you tend to ignore them after a while. There is usually no treatment required for these conditions.

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*In extremely rare circumstances the drops can increase your eye pressure, so if you notice any of the following symptoms…

  • Red painful eye
  • Haloes around lights
  • Nausea/Stomach cramps

You must go straight to your local eye casualty.