Do you see spots or threads moving in your field of vision? It's not uncommon

When you close your eyes, you might be able to see them. Or when you rest your gaze on a white wall or a blue sky.

Strange formations, either dark or transparent, floating around on the retina. When you try to focus on them, they slip away, moving up, down, or sideways.

These are called floaters.

"They aren't located on the retina itself, but in the clear, jelly-like substance that fills the inside of the eye," says Rigmor Baraas, professor at the University of South-Eastern Norway.

But why are they there? Are they caused by eye damage from too much sun exposure without sunglasses? And can we ever get rid of them?

How common are they?

The scientific name is Muscae volitantes.

One study shows that 76 per cent of Americans experience floaters in their field of vision.

Baraas does not know how many people in Norway have them.

"But it's not uncommon," she says.

What are they?

So what exactly are these floating spots?

"They are small clusters of cells or strands of protein," says Baraas.

They are located inside the vitreous body of the eye, which is the jelly-like substance at the back of the eye.

When light enters the eye through the lens, specific cells on the retina are activated. As floaters move within the vitreous body, they cast shadows on the retina, creating the odd shapes many people see.

Such as small spots, threads, transparent worms, and cloud formations.

Here you can watch a video about floaters from TED Ed: 

Why do we get them?

For most people, floaters don't cause any real trouble.

The older we get, the more of them tend to appear.

"As we age, the vitreous body shrinks slightly and becomes more fluid," says Baraas.

This change is usually what leads to floaters forming. They are a normal part of the ageing process, according to Baraas.

Floaters are therefore more common in people over the age of 50, although some people experience them earlier in life as well.

Are they dangerous?

"They are usually completely harmless," says Baraas.

She notes that they can also appear after eye surgery, eye injuries, or following an eye infection.

However, if you suddenly notice a rapid increase in floaters, you should consult an optician or ophthalmologist.

———

Translated by Alette Bjordal Gjellesvik

Read the Norwegian version of this article on forskning.no

Related content:

Do we see the same colours?

Why you shouldn't be on your phone after going to bed

Subscribe to our newsletter

The latest news from Science Norway, sent twice a week and completely free.

Sign up