Flashes & Floaters

Floaters are something many will not need to worry about although they can be distracting. There is however the potential for a floater to be a warning sign of a more serious condition. While we are corneal specialists (front of the eye) rather than retinal specialists (back of the eye), we do have close links with highly skilled and trusted retinal surgeons.


Types of


Eye floaters are small pieces of debris that float in the eye’s vitreous humor. This debris casts shadows onto the retina (the light-sensitive tissue layer at the back of the eye). If you have eye floaters, it is these shadows that you see “floating” across your field of vision.

Fibrous Strand Floater

Most common in young people, this thin, dense floater can appear as multiple dots and/or string-like cobwebs and is a result of clumping of the collagen fibers of the vitreous. Depending on size, and where it is located, it may be treatable with vitreolysis.

Fibrous Strand Floaters

Diffuse Floater

This cloud-like floater is caused by the natural aging process. Whilst this type of floater can sometimes be treated with vitreolysis, it often requires more overall treatment in order to obtain satisfactory results.

Diffuse Floater

Weiss Ring Floater

The ring-shaped Weiss Ring floater is a large, fibrous floater that is usually located safely away from the crystalline lens and the retina. Because of this, it can be treated safely and effectively with vitreolysis.

Weiss Ring Floater

What do they mean?


As you get older, your risk of developing floaters increases. Floaters tend to occur in people who are over 40 years of age and are most common in those who are in their 60s and 70s. However, some younger people may also develop floaters.

As you get older, the vitreous humour in the middle of your eyeball can become less firm and strands of a protein called collagen may become visible within it. The collagen strands may appear to swirl as your eyes move.

Normally, light travels through the clear layer of vitreous humour to reach the retina. The retina is the light-sensitive layer of cells at the back of your eye that turns what you are looking at into an image, and transmits this to your brain. Floaters can cause shadows as they float through the fluid in your eye.

Posterior vitreous detachment (PVD)

Floaters can be a symptom of posterior vitreous detachment. This is a common condition that occurs in about three-quarters of people over 65 years of age. PVD can occur as the result of changes to the vitreous humour as the eye gets older.

As we get older the central part of the vitreous humour becomes more liquid and the outer part, known as the cortex, starts to shrink away from the retina. Floaters are created as a result of the collagen clumping together.

Flashing lights can also be another symptom of PVD. Flashing lights may occur when the outer vitreous humour pulls on the light-sensitive tissue of the retina. The pulling on the retina causes brain to interpret it as a light signal.

Retinal detachment

Floaters may be a sign of retinal detachment (when the retina separates from the wall at the back of the eye). If you have retinal detachment, you will usually have:

  • a large number of floaters
  • flashing lights
  • loss of vision

There are several types of surgery to repair a detached retina. The type of procedure your Consultant Ophthalmic Surgeon performs will depend on the severity of retinal detachment.

If you think that you may have retinal detachment, seek urgent medical attention from your GP or optometrist (optician). If you are patient of Centre for Sight already please call 01342 306020.

If you are unsure about your loss of vision contact one of our Patient Co-ordinators who can arrange an appointment for you to see one of our surgeons. Call 0800 0112882 or email us here.

Author Information

Authored by Sheraz Daya MD FACP FACS FRCS(Ed) FRCOphth, Consultant Ophthalmic Surgeon & Medical Director, June 2019.

Next review due June 2024.