Types of Cataracts

All cataracts are fundamentally a change in the clarity of the overall lens structure; however, cataracts may result either early in life or as a result of aging, and different portions of the lens may be more affected than others. Cataracts that occur at birth or present very early in life (during the first year of life) are termed congenital or infantile cataracts. These cataracts require prompt surgical correction or they may prevent the vision in the affected eye from developing normally. When the central portion of the lens is most affected, which is the most common situation, these are termed nuclear cataracts. The outside of the lens is called the lens cortex, and when opacities are most visible in this region, the cataracts are called cortical cataracts. There is an even more specific change that occasionally happens, when the opacity develops immediately next to the lens capsule, either by the anterior, or more commonly the posterior, portion of the capsule; these are called subcapsular cataracts. Unlike most cataracts, posterior subcapsular cataracts can develop rather quickly and affect vision more suddenly than either nuclear or cortical cataracts.