How to Say It: KAT-ah-rakt


A cataract is a clouding of the eye's lens. This makes it hard for a person to see. It gets worse over time.


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Cataracts happen when proteins break down in the lens. Aging is the most common cause. Other causes are:

  • Certain health problems, such as diabetes
  • Exposure to x-rays or radiation
  • Eye injury

Some children are born with cataracts. They may also be found in babies and older children. This is rare.

Risk Factors

This problem is more common in older adults. Other things that may raise the risk are:


A person may not have symptoms in the early stages. As the cataract gets worse, problems may be:

  • Cloudy or blurry vision
  • Reduced vision
  • Glare and haloes from light
  • Double vision
  • Poor contrast
  • Colors that seem faded
  • Problems recognizing faces or objects that are far away
  • Poor night vision


The doctor will ask about your symptoms and health history. This is often enough to suspect the diagnosis.

An eye exam will be done by a doctor who treats eye problems. The doctor will use special tools and tests to check the health of the eyes. This is enough to make the diagnosis.


The goal of treatment is to improve vision. Some people may be able to manage symptoms with updated eyeglasses. However, surgery is the only way to remove a cataract that is causing problems. It removes a cloudy lens and replaces it with an artificial one.


To lower the risk of this problem:

  • Avoid smoking.
  • Wear a hat and UV-protected sunglasses when outdoors.
  • Wear safety glasses when doing tasks that may result in eye injury.


Eye Smart—American Ophthalmology
National Eye Institute


Canadian National Institute for the Blind
Canadian Ophthalmological Society


American Academy of Ophthalmology (AAO). Preferred practice pattern on cataract in the adult eye. AAO 2016 Oct.
Cataracts. National Eye Institute website. Available at:
...(Click grey area to select URL)
Accessed December 30, 2020.
Cataracts in adults. EBSCO DynaMed website. Available at: Accessed December 30, 2020.
Last reviewed December 2020 by EBSCO Medical Review Board Daniel A. Ostrovsky, MD
Last Updated: 12/30/2020