Floaters and flashes

What are floaters?

Floaters appear as black spots or something that looks like a hair or small pieces of a cobweb.These can be semi-transparent or dark and appear to float in front of your vision. If you have had these for years, your eye and your brain learn to ignore them. Sometimes the number of floaters increases as you get older. Occasionally an increase in floaters can be a sign of problems inside the eye. As 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. Some people find that floaters can be a nuisance but most people become used to them. They rarely cause problems with your vision.

If you experience a sudden onset floater/floaters please contact us for an urgent appointment on 0191 5208059. Most sudden onset floaters are caused by posterior vitreous detachment (see below),which does not usually cause serious problems, however sometimes they are a sign of a retinal tear or detachment. If we are not available please contact Eye Casualty at Sunderland Eye Infirmary.

Why do floaters happen?

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 gel separates into a watery fluid and wavy collagen fibrils. You see the fibrils as line-shaped floaters. Sometimes the gel shrinks enough to collapse away from the light sensitive lining at the back of your eye which is called the retina. Once the gel has collapsed, some people see a large ring-shaped floater. This is called a posterior vitreous detachment or PVD. If the vitreous gel collapses, it can pull on your retina. If this happens, you would see this as flashes of light – see ‘Flashes’, below. Floaters can also be caused by some eye diseases that cause inflammation. However, this is not very common.

 Who is at risk of floaters?

Floaters are more common in people who are short sighted. The floaters 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. Sometimes they may be annoying, but treatment is not advised. Occasionally a sudden increase in floaters – either one or more large ones or a shower of tiny ones – may be a sign of more serious eye disease such as a retinal detachment. This is when your retina pulls away from the back of your eye and it may lead to a sudden increase in floaters and possibly a blank spot or shadow in your vision which does not go away. If you get these symptoms please contact us to arrange an urgent appointment. If we are not available please contact Eye Casualty at Sunderland Eye Infirmary.

 What are flashes?

Some people may see flashes of light in front of their eyes, like small sparkles, lightning or fireworks. You should not confuse these with the shimmering or zig-zag lines that may be part of a migraine. Migraine shimmers are normally in both eyes. You can tell whether the shimmers are in one or both eyes by covering each eye in turn and seeing if the shimmers are still there. Some people may get migraine shimmers even if they do not have a headache afterwards. Flashes happen when there is a pull on your retina. This might happen as the vitreous gel inside your eye becomes more liquid and collapses. You may experience flashes occasionally, on and off over weeks or months. Flashes can also happen 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.

 What might happen if I have flashes?

Sometimes flashes just mean that there is a tug on the retina and nothing more. However, some types of 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 as well. If you have a sudden onset of flashes, please contact us to arrange an urgent appointment. If we are not available please contact Eye Casualty at Sunderland Eye Infimary.

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 disease such as Marfans syndrome (a rare genetic

  disease which affects the connective tissues including in the eye).

If you have any concerns or queries, please telephone 0191 5208059 to make an appointment at RJ Naisbitt Optometry in South Hetton, Durham.

The College of Optometrists

42 Craven Street

London, WC2N 5NG

Tel: 020 7839 6000

Email: optometry@college-optometrists.org



© College of Optometrists 2011