Eye Health

Updated 07 March 2018

Causes of cataracts

Cataracts are clouding of the normally clear lens portion of the eye and are associated with age, long-term UV exposure, diabetes among other factors


There are a number of factors that can contribute to the development of cataracts. These include:

  • Cataracts are associated with ageing and are common in older adults. About 75 percent of all cataracts are age-related.
  • Exposure to ultraviolet (UV) radiation (e.g. from sunlight)
  • Eye injuries. Sharp or blunt injuries may cause a cataract.
  • Diabetes, especially when blood sugar is poorly controlled.
  • Cataracts may develop as a secondary effect of other eye ailments, such as glaucoma (raised pressure within the eye) or uveitis (inflammation in the eye).
  • Long-term use of certain medications, most notably steroids, may cause cataracts.
  • Radiation treatment to the head or even when struck by lightning or electrocution
  • Some babies are born with cataracts (congenital cataracts) or develop them shortly after birth.
  • Hereditary factors

Read more:

Symptoms of cataracts

Diagnosing cataracts

Treating cataracts


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Megan Goodman qualified as an optometrist from the University of Johannesburg. She has recently completed a Masters degree in Clinical Epidemiology at Stellenbosch University. She has a keen interest in ocular pathology and evidence based medicine as well as contact lenses.

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