A cataract is a clouding of the eye’s natural lens, which lies behind the iris and the pupil.
Cataracts are the most common cause of vision loss in people over age 40 and is the principal cause of blindness in the world.
To date, no medication or eye drop has been proven to prevent or reverse cataract formation. The only treatment for a cataract, however, is surgical removal of the natural lens. A cataract should not be removed simply because it is present. Many people have cataracts that have not caused blurred vision, interfere with activities of daily living, or otherwise prevent them from their productive lives.
However, if an individual has blurred vision that makes it difficult to read print or read signs while driving; has disabling glare while driving at night; or has difficulty engaging in other daily activities, it is time to consider cataract surgery. If there are cataracts in both eyes that require surgery, the surgeries are usually performed several weeks apart. Cataract surgery on both eyes at the same time is not recommended because there is a possibility of complications affecting both eyes; the most worrisome is infection.
Types of cataracts include:
- A subcapsular cataract occurs at the back of the lens. People with diabetes or those taking high doses of steroid medications have a greater risk of developing a subcapsular cataract.
- A nuclear cataract forms deep in the central zone (nucleus) of the lens. Nuclear cataracts usually are associated with aging.
- A cortical cataract is characterized by white, wedge-like opacities that start in the periphery of the lens and work their way to the center in a spoke-like fashion. This type of cataract occurs in the lens cortex, which is the part of the lens that surrounds the central nucleus.
