Floaters are small, dark spots or strands that appear to float in front of your eyes, they are very common and are usually harmless. Floaters are more common if you are short sighted or as you get older. Sometimes people notice they see flashes of light, these can be due to movement of the gel inside the eye. Very occasionally, flashes or an increase in floaters can be a sign of a retinal detachment, which is an ocular emergency. This is more common as you get older, or in people who are very short sighted.

If you get any of the following symptoms and you cannot contact your optometrist, you should seek urgent help from your local casualty department at the hospital. It is important that you seek advice promptly if you have:

  • a sudden increase in floaters, particularly if you also notice flashing lights
  • a new, large, floater
  • a change in floaters or flashing lights after you have had a direct blow to your eye
  • a shadow spreading across the vision of one of your eyes

What are floaters?

Floaters appear as black spots or small pieces of a cobweb, they appear to float in front of your vision. Sometimes the number of floaters increases as you get older. Sometimes an increase in floaters can be a sign of a problem inside the eye.

Because they ‘float’ in the jelly of your eye, you will find that if you move your eye to try to look at a floater it will move away in the direction you move your eye. You might only see the floater if you are staring at a light coloured surface or at the sky during the day.

They rarely cause problems with the vision, but they can be irritating to the viewer.

Why do floaters occur?

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 shrinkage of the vitreous gel can pull on your retina. If this happens you would see this as flashes of light.

Who is at risk of floaters?

Floaters are more common in people who are short sighted. They may increase if you have had an eye operation such as cataract surgery, or laser treatment after cataract surgery.

What might happen if I have floaters?

Most of the time floaters are harmless.

Occasionally a sudden increase in floaters may be a sign of more serious eye problem such as a retinal detachment. Sometimes, the floaters will be accompanied by blank patches in your vision. This needs urgent medical attention, you should contact your optometrist straight away, or go straight to the local A&E department. If you can not do this you should seek urgent attention from an eye casualty department at the hospital. An ophthalmologist will need to view inside your eyes to check if your retina is damaged.

What are flashes?

Flashes occur when there is a pull on your retina. This might happen as the vitreous gel inside your eye shrinks. You may experience flashes occasionally. Flashes can also occur if you are hit in the eye.

Flashes related to a collapse of the gel inside the eye are more likely to happen as you get older.

Sometimes flashes just indicate a tug on the retina, but constant flashes may be a sign of a retinal detachment.

A retinal tear or retinal detachment may lead to a sudden increase in floaters as well as flashes. You might notice a shadow at the edge of your vision too. This needs immediate attention at the hospital.

What might happen if I have flashes?

Sometimes flashes just indicate a tug on the retina and nothing more. However constant flashes may be a sign of a retinal detachment.

A retinal tear or retinal detachment may lead to a sudden increase in floaters as well as flashes. You might notice a shadow at the edge of your vision too. This needs immediate attention. If you notice these symptoms you should contact your optometrist straight away. If you can not do this you should seek urgent attention from an eye casualty department at the hospital. If there is no eye casualty department nearby you can go to your usual hospital casualty department, but it is best to go to an eye casualty department if you can. An ophthalmologist, a specialist eye doctor, will need to use eye drops and a special light to look inside your eyes to check if your retina is damaged.

Who is at risk of a retinal detachment?

Some people are more at risk of a 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 had a previous eye injury
  • have a family history of retinal detachment • have had a previous 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.