What is a Cataract?

The normal eye contains a structure called the crystalline lens. This, under normal circumstances, is transparent in nature. A clouding up or opacification of the lens is called a cataract. It may cause disturbance or diminution of vision.

A Mature Cataract


Cataracts, usually, are age-related in nature. They tend to affect older people more often, usually over the age of 50yrs. Sometimes they may occur in younger individuals as well and may be related to predisposing factors like diabetes, certain eye diseases like uveitis, excessive use of some medications like steroids, over-exposure to ultra-violet light, trauma, etc. Cataracts are uncommon in infants and children but may be caused by metabolic disorders, genetic diseases or injury.


The clear crystalline lens helps to focus light rays onto the retina of the eye. When a cataract develops, irregular refraction of light by the same lens results in visual disturbances. Some of the symptoms which a patient with cataract can experience, include the following.

  • Diminution of vision
  • Glare, specially with headlights of oncoming traffic
  • Halos around lighted objects
  • Multiple images, like multiple moons
  • Difficulty in bright light with better vision in dim light
  • Difficulty in dim light with better vision in bright light
  • Blurring of vision
  • Frequent change of glass power


The universal treatment of cataract involves the removal of the cloudy lens, which is then replaced by an artificial lens. Phaco-emulsification is most commonly used for cataract extraction. Cataracts are not amenable to medical treatment. They cannot be treated with any topical, oral or other medication.

Know More Cataract