Flashes and Floaters

Floaters appear as dark shapes that appear to float in front of the eye. The shapes may be round, oval or irregular, and by middle age most people will have these to a greater or lesser extent. Floaters move with eye movement and are usually most obvious against a bright background such as a white wall.

Floaters may sometimes interfere with vision, but most often they are simply a nuisance. They are most commonly caused by imperfections in the gel or vitreous in the back of the eye. Less common causes include blood, inflammatory or even malignant cells.

Flashes occur in a number of different conditions. Most often they are caused by separation of the vitreous gel from the back of the eye. They may also occur with migraine or with blockage of blood vessels in the back of the eye. Flashes may last for a few seconds, or several minutes at a time.

When should you be seen by an ophthalmologist?

  • New onset of flashes or floaters (old, long-standing floaters are unlikely to be of concern)
  • ‘Wavy’ or ‘watery’ vision
  • A veil or curtain obstructing part of the field of vision
  • Flashes associated with floaters, headache, scalp tenderness or episodes of loss of vision
  • A sudden decrease in vision