Eye floaters and flashes

What are eye floaters and flashes?

Eye floaters and flashes are both caused by the natural shrinking of the gel-like fluid in your eye that happens with age. Floaters are small, cloudy particles of various shapes and sizes floating in the jelly fluid inside the eye called the vitreous. They’re especially noticeable when out in the sun or looking at light backgrounds. They move as your eyes move and may seem to disappear when you try to look at them directly. 

When it comes to flashes, you may see a brief flash of light in an arc shape in the periphery of your vision normally in the dark, which can come and go. These are different to the shimmering or zigzag lines that might be part of a migraine.

What causes floaters and flashes in the eye?

Eye floaters and flashes can occur spontaneously, but tend to occur more frequently as you get older. The gel in the eye naturally becomes more liquid and shrinks. Sometimes, the gel can shrink enough to completely separate from the light-sensitive area at the back of the eye (the retina), which can produce a ring-shaped floater.

Even though these spots are usually harmless and do not affect vision, they can be signs of more serious problems such as retinal detachment.

Why do eye floaters and flashes occur?

These usually occur when the gel inside your eye shrinks and pulls on the retina. This will sometime lead to a brief flash. Constant flashes, especially if associated with a shadow in the corner of the vision, may be a sign of a retinal tear or retinal detachment (where the retina becomes separated from its underlying layer), which is a rare but serious eye condition that requires immediate treatment to prevent permanent vision loss.

How do I know if I have a problem?

Please seek immediate attention at your Opticians or local eye casualty department if you develop any of the following symptoms:

• A sudden increase or shower of floaters
• Flashes of light in the corners of your vision
• A new, large floater
• Loss of vision - whether in part or full, like a shadow or curtain spreading across the vision
• Change in floaters or flashes after you receive a blow to the eye and/or head

How do I get help?

If you feel you are experiencing flashes and floaters, contact your optician or doctor immediately. If they’re unavailable, visit your nearest emergency department.