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What is a cataract?

Every normal human eye contains a crystalline lens that helps the eye to focus images, much like the lens inside a camera that brings images into focus on the film. When we are born, this lens is made up of clear proteins.

Over time with the normal aging process, and with environmental factors such as UV light, poor nutrition, or smoking, the lens becomes cloudy. This clouding of the normal crystalline lens is irreversible, and is called a cataract. As the cataract becomes more densely clouded, the lens progressively scatters more light and results in poor vision.

Risk Factors

  • Advancing age
  • Hereditary
  • Chronic steroid use
  • Diabetes
  • Radiation and chemotherapy


  • Glare
  • Halos
  • Blurry vision
  • Difficulty driving at night and difficulty seeing road signs
  • Loss of color perception
  • Loss of contrast sensitivity
  • Light sensitivity
  • Sometimes patients are asymptomatic and are surprised to find out that they have cataracts!


Cataracts can only be diagnosed through a visit to an eye doctor, where they will use a specialized instrument called a slit lamp to evaluate the eye. A slit lamp is a microscope used to examine both the inner and the outer tissues of the eye.