A Cataract is an eye disease in which the clear lens of the eye becomes cloudy or opaque, causing a decrease in vision. Most cataracts develop slowly and do not disturb the eyesight early on. But with time, cataracts will eventually interfere with the vision. For people who have cataracts, seeing through cloudy lenses is a bit like looking through a frosty or fogged-up window. Clouded vision caused by cataracts can make it more difficult to read, drive a car or see the expression on a person's face.


At first, the cloudiness in the vision caused by a cataract may affect only a small part of the eye's lens and the patient the patient may not even notice any symptoms that will leave him unaware of any vision loss. As a cataract becomes more advanced, decrease in clarity of vision, not fully correctable with glasses, is noticed. There is a loss of contrast sensitivity, so that shadows and color vision are less vivid and night vision will be diminished. In certain types of cataracts, double vision may be noted in the affected eye. Some patients note that they require frequent changes in their eyeglass or contact lens prescriptions and may be aware that their near vision is improving as their distance vision declines.

A cataract does not routinely cause discomfort or pain in the eye or alter the external appearance of the eye.


Most cataracts develop when aging or injury changes the tissue that makes up the eye's lens. There are many causes of non age-related cataracts that are a result of similar changes to the protein of the lens, also resulting in visual blurring or visual loss. Some cataracts are related to inherited genetic disorders that cause other health problems and increase the risk of cataracts. Cataracts can also be caused by other eye conditions, medical conditions such as diabetes, trauma or past eye surgery. Long-term use of steroid medications can cause cataracts to develop as well.


Occasionally, a very dense cataract of long-standing duration may enlarge in size and interfere with fluid drainage within the eye. In addition, a far advanced cataract may leak protein into the eye, causing inflammation of the eye.

Risk Factors

Factors that increase the risk of cataracts include:

  • Increasing age;
  • Diabetes;
  • Drinking excessive amounts of alcohol;
  • Excessive exposure to sunlight;
  • Exposure to ionizing radiation;
  • Family history of cataracts;
  • High blood pressure;
  • Obesity;
  • Previous eye injury or inflammation;
  • Previous eye surgery;
  • Prolonged use of corticosteroid medications;
  • Smoking.


No studies have proved how to prevent cataracts or slow the progression of cataracts. However, doctors think several strategies may be helpful, including:

  • Have regular eye examinations;
  • Quit smoking;
  • Reduce alcohol use;
  • Wear sunglasses;
  • Manage other health problems;
  • Maintain a healthy weight;
  • Choose a healthy diet that includes plenty of fruits and vegetables.