Floaters and Flashes

By middle age, most people see small dark shapes that appear to float in their field of vision. These are called floaters. They are particles in the vitreous body, a jelly-like substance that fills the inside of the eye. The vitreous body is attached to the retina, the layer of light-sensitive tissue at the back of the eye. Floaters appear because they cast shadows on the retina.

Small flashes of light may be seen with or without floaters. Flashes are usually caused by the vitreous body tugging on the retina. This tugging occurs when the vitreous body shrinks with age. The shrinking vitreous body often separates from the retina (posterior vitreous detachment).

Floaters and flashes are usually just annoying, not harmful. However, the sudden onset of many new floaters or flashes could be a warning of looming serious eye problems, including tears of the retina or a detached retina.

Click here to view a RANZCO information sheet on Floaters and Flashes.

Retinal Detachment

The retina is a light-sensitive layer of tissue that lines the inner surface of the eye. It captures light and sends signals to the brain that result in vision. When a retinal detachment occurs, the retina is separated from the underlying tissue and stops functioning. Wherever the retina detaches, vision is lost and a shadow develops. This can lead to total blindness in the affected eye. In most cases, the cause is a retinal tear or hole.

Risk factors

  • increasing age
  • short-sightedness
  • abnormalities of the retina
  • a personal or family history of retinal detachment
  • previous cataract surgery
  • trauma.

Click here to view an information sheet from RANZCO on Retinal Tears.