What is a Cataract

What is a Cataract?

The lens in an eye enables clear vision. A cataract is the progressive clouding of this lens and is one of the leading causes of vision impairment. For people with cataracts, seeing the world is like looking through a fogged window. Cataracts do not cause pain and usually develop slowly over time as a result of the natural ageing process.

Among Australians aged 55 and over, cataract is the primary cause of visual impairment in 40% of cases.1 

What are the symptoms? 

  • Blurred, dim or clouded vision.
  • Difficulty seeing at night or low light conditions.
  • Glare or bright light sensitivity.
  • Distorted or double vision in the affected eye.
  • Seeing ‘halos’ around lights.

Who is at risk of developing cataracts?

  • Diabetics
  • Smokers
  • People with a family history of the condition

The risk is also increased among people who have experienced extended eye exposure without protection or who have sustained an eye injury.

However, most cataracts occur due to ageing. At the onset, vision changes may not be noticeable or minor. If left untreated, the cataract can grow larger resulting in more obvious symptoms, significant loss of vision and possible blindness.


Early-stage symptoms may not require surgery and can be managed with prescription glasses. Cataract surgery becomes necessary as the vision and other symptoms worsen and quality of life is affected.


  1. Australian Commission on Safety and Quality in Health Care. Consumer information on cataract surgery: An environmental scan. Sydney: ACSQHC; 2018References