Many cataracts take years to develop to the point where vision is seriously affected. Most occur as a result of the normal aging process. The types of age-related cataracts are usually described by their location in the lens. They are: nuclear cataracts, cortical cataracts and subcapsular cataracts.
Nuclear cataracts occur in the center of the lens and may induce other eye problems, such as myopia. A cortical cataract, which tends to occur more in persons with diabetes, begins at the outer portion of the lens, then slowly moves inward. Subcapsular cataracts develops under the capsule, often at the back of the lens. This type of cataract also occurs more in persons with diabetes, but it is also found in persons with high myopia, adults with retinitis pigmentosa and in people who take steroids.