Patients and Public

Eye Diseases


Cataract is a clouding of the lens inside the eye which leads to a decrease in vision either in one or both eyes .The lens is the transparent structure of the eye that sits just behind your pupil (the black dot in the centre of your eye). It allows light to get to the back of your eye (retina)

It cannot spread from one eye to the other. However it is a most common cause of blindness in South Africa.

Causes a cataract

The lens of the eyes is made mostly of water and protein. Cataracts occur when there is a build-up of protein in the lens, making the lens it cloudy. This makes the lens to lose its transparency thus prevents light from passing clearly through the lens, causing some loss of vision.

Types of cataracts include:
  • Age-related cataracts. This type of cataract develops as a result of aging. The risk of having a cataract increases after age 60, and by age 80,
  • Congenital cataracts. Babies are sometimes born with cataracts as a result of an infection, injury, or poor development before they were born, or they may develop during childhood.
  • Secondary cataracts. These develop as a result of other medical conditions, like diabetes, or exposure to toxic substances, certain drugs (such as corticosteroids or diuretics), ultraviolet light, or radiation.
  • Traumatic cataracts. These form after injury to the eye.

There are other factors that may increase your risk of developing cataracts, including;
  • Smoking
  • Alcohol use
  • Diabetes
  • Prolonged exposure to the sun
  • History of cataracts in your family
  • Poor diet lacking in vitamins
  • Your vision may become blurry, as if looking through a foggy window
  • Colours may not appear as bright as they once did thus leading to difficulty in appreciating colours and changes in contrast, driving, and reading.
  • Problems driving at night such as glare from oncoming headlights and lights in general.
  • Double vision
  • As the cataract grows, it may be harder for you to read
  • You may also need to change to your spectacles

Symptoms of cataract

Cataracts usually form slowly and may cause few unnoticeable changes to vision.

A person with cataract may experience the following symptoms:

Hazy or blurred vision may mean you have a cataract.

Diagnosis and Treatment of Cataracts

Regular eye examination is important, as cataract screening is part of the examination.

During an eye examination a series of tests will be performed to check how well you can see Your SAOA Optometrist is trained to assess and examine the condition of your the lens and other parts of the eye.

Surgery has been proven to be effective in treating cataract. This will usually be recommended if your loss of vision has a significant effect on your daily activities, such as driving or reading.


WHO- World health organization
Jack.J Kansk,i Clinical Opthalmology