Floaters and Flashes

Floaters look like small, dark spots or strands that appear to float in front of your eyes. They are very common and normally harmless. They are more common if you are short sighted or as you get older.

Some people report flashes of light. This can be due to movement of the gel inside the eye.
Very occasionally, flashes or an increase in floaters can indicate retinal detachment, which needs immediate treatment.

Symptoms that require immediate attention are:

A sudden increase in floaters, particularly flashing lights
A change in floaters or flashing lights after you have had a direct blow to the eye
A shadow spreading across the vision of one of your eyes

What causes floaters?

Some people are born with floaters, other floaters occur as you get older when the gel in the eye, the vitreous humour, naturally shrinks. The collapse of the vitreous gel can pull on your retina causing flashes of light. If you notice these symptoms, you should contact your optometrist immediately.

What are flashes?

Some people see flashes of light in front of one of their eyes, like small sparkles, lightening or fireworks. They tend to be in the extreme corners of your vision, come and go and don’t obscure any part of your vision. The flashes don’t last for a defined length of time and you may notice them more if you go from a light to dark environment. They may continue for several months.

These are different to the shimmering or zig-zag lines that are often caused by a migraine. Migraine shimmers are a flickering of light, often on only one side of your vision which then expand to the outside of your vision with a sort of jagged pattern, often obscuring part of your vision (left or right side). The shimmers usually go away after 10-20 minutes and may be followed by a headache.

Who is at risk of retinal detachment?

These are people who:

Have had eye surgery, such as a cataract operation or laser surgery after a cataract operation
Are moderately short-sighted (over -3.00D)
Have a family history of retinal detachment in that eye or the other eye
Are over the age of 50
Have certain retinal diseases such as lattice or other retinal degeneration
Have certain systemic diseases such as Marfan syndrome