What to do... if you have floaters and flashing lights?

Leo Sheck
Minute read

You can find a printable copy of this leaflet here.

Floaters and flashing lights are common problems. In most cases, the cause is benign but uncommonly these symptoms can represent a more serious pathology. Here is a guide on what to do if you have floaters and flashing lights.

What cause floaters and flashing lights?

Floaters are caused by debris in the vitreous inside the eye. The vitreous is a jelly in the centre of the eyeball in front of the retina. Due to aging, there is gradual clumping and degeneration of the vitreous. In some patients, there can be a sudden detachment of the posterior vitreous resulting in a Weiss ring, which you will notice as a floater. Posterior vitreous detachment is the most common cause of floaters, but rarely inflammation or bleeding from the posterior segment (i.e. retina and surrounding structures) can result in floaters.

The symptom of flashing lights is due to traction (pulling) of the vitreous on the retina. The retina does not have any pain sensor, and any mechanical stimulus will generate a light signal which is interpreted as flashing lights. You can demonstrate this by gentling pressing on the eye with the eye closed.

What to do when you notice floaters and flashing lights?

Although most cases of floaters and flashing lights are benign, you need to be examined by an eye specialist to exclude any serious condition. Usually an examination with an optometrist within 2-3 days will be sufficient if you do not have any risk factors for serious pathology.

Risk factors for pathology in floaters and flashing lights

  • Previous retinal detachments or retinal tear
  • Systemic condition affecting the vitreous (e.g. Stickler's syndrome)
  • High myopia (> -5D)
  • Family history of retinal detachments
  • Known diabetic retinopathy
  • History of uveitis

If you have any of these risk factors, you should be seen by an ophthalmologist (eye surgeon) within 24 hours.

While you are waiting for your appointment, you should refrain from heavy exercise. Light walking is fine but nothing more strenuous until your retina has been checked.

What to expect when you see Dr Sheck?

Dr Sheck is more than happy to see you urgently for flashes and floaters for a detailed assessment. You will have a dilated fundal examination to ensure your retina is healthy, along with a 3-mirror examination so Dr Sheck can evaluate the far periphery of the retina. You will also have OCT imaging to check the status of the vitreous, and an Optos imaging to look for subtle peripheral retinal tears.

The entire examination is painless and takes around 30 minutes. If your examination is normal, it is highly unlikely for you to develop any subsequent retinal complications.

How to treat a retinal tear or detachment?

Retinal tears are treated by laser retinopexy, which you can find out more from the accompanying leaflet. In the unlikely case of a retinal detachment, surgery is required (either vitrectomy or scleral buckle) to restore the anatomy of the eye. You can decrease the risk of a retinal detachment by obtaining a prompt examination.

Can you remove floaters?

Floaters can be removed by a vitrectomy surgery. This is a minimally invasive operation where the vitreous is removed in its entirely. However, there are risks associated with this procedure and in most cases, the risks outweigh the potential benefits.

Previously laser treatment to floaters has been used but the effectiveness of this procedure is suboptimal.

About Dr Leo Sheck

Dr Sheck is a RANZCO-qualified, internationally trained ophthalmologist. He combined his initial training in New Zealand with a two-year advanced fellowship in Moorfield Eye Hospital, London. He also holds a Doctorate in Ocular Genetics from the University of Auckland and a Master of Business Administration from the University of Cambridge. He specialises in medical retina diseases (injection therapy), cataract surgery, ocular genetics, uveitis and electrodiagnostics.