2. Development of any opacity in the lens or its capsule. Cataract,
thus may occur, either due to formation of opaque lens fibres
(congenital and developmental cataracts) or due to
degenerative process leading to opacification of the normally
formed transparent lens fibres (acquired cataract).
4. I. Congenital and developmental cataract
II. Acquired cataract
1. Senile cataract
2. Traumatic cataract
3. Complicated cataract
4. Metabolic cataract
5. Electric cataract
6. Radiational cataract
7. Toxic cataract e.g.,
i. Corticosteroid-induced cataract
ii. Miotics-induced cataract
iii. Copper (in chalcosis) and iron (in siderosis) induced cataract
8. Cataract associated with skin diseases (Dermatogenic cataract)
9. Cataract associated with osseous diseases
10. Cataract with miscellaneous syndromes e.g.,
i. Dystrophica myotonica
ii. Down’s syndrome
iii. Lowe’s syndrome
iv. Treacher-Collin’s syndrome.
5. B. Morphological classification
1. Capsular cataract. It involves the capsule and may be:
i. Anterior capsular cataract
ii. Posterior capsular cataract
2. Subcapsular cataract. It involves the superficial most part of the
cortex (just below the capsule) and includes:
i. Anterior subcapsular cataract
ii. Posterior subcapsular cataract
3. Cortical cataract. It involves the major part of the cortex.
4. Supranuclear cataract. It involves only the deeper parts of cortex
(just outside the nucleus).
5. Nuclear cataract. It involves the nucleus of the crystalline lens.
6.
7. 6. Polar cataract. It involves the capsule and superficial
part of the cortex in the polar region only and may be:
i. Anterior polar cataract
ii. Posterior polar cataract
