Floaters look like small, dark spots or strands that float in front of your eyes. Floaters are very common and normally harmless. They are more common if you are short sighted or as you get older. Some people notice flashes of light. These can be due to the movement of the gel inside the eye. Very occasionally, flashes or an increase in floaters can be a sign of retinal detachment, which needs treating as soon as possible. This is more common as you get older, or in people who are short sighted or have had eye surgery.

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 gel separates into a watery fluid and wavy collagen fibrils. The fibrils are seen 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.
The collapse of vitreous gel can pull on your retina. If this happens you would see this as flashes of light. Floaters can also caused by some eye diseases that cause inflammation. This is not very common.

People at risk may include:

Short-sighted people

People that have had an eye operation such as cataract

People that have had laser treatment after cataract

What should I do 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 a more serious eye disease such as retinal detachment.

Retinal Detachment

Retinal detachment is when your retina pulls away from the back of your eye. 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.

Retinal detachment needs immediate attention. If you notice these symptoms you should contact your optometrist straight away. If you cannot do this you should seek urgent attention from an eye casualty department at the hospital. If there is not 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 us eye drops and a special light to look inside your eyes 
to check if your retina is damaged.