By Tina D. Turner, M.D. Updated by Sefy Paulose, M.D., March, 2022

Types of Cataracts

There are various kinds of cataracts – types formed by trauma, congenital and age-related. The three primary types of age-related cataracts are nuclear sclerotic, cortical and posterior subcapsular. As we age, any one type or a combination of all three types can develop over time.

Nuclear Sclerotic Cataracts

This is the most common type of age-related cataract, caused primarily by the hardening and yellowing of the lens over time. “Nuclear” refers to the gradual clouding of the central portion of the lens, called the nucleus; “sclerotic” refers to the hardening, or sclerosis, of the lens nucleus. As this type of cataract progresses, it changes the eye’s ability to focus, and close-up vision (for reading or other types of close work) may temporarily improve. This symptom is referred to as “second sight,” but the vision improvement it produces is not permanent. A nuclear sclerotic cataract progresses slowly and may require many years of gradual development before it begins to affect vision.

Risk for cataracts?

Your risk for cataracts goes up as you get older. You’re also at higher risk if you:
  • Have certain health problems, like diabetes
  • Smoke
  • Drink too much alcohol
  • Have a family history of cataracts
  • Have had an eye injury, eye surgery, or radiation treatment on your upper body
  • Have spent a lot of time in the sun
  • Take steroids (medicines used to treat a variety of health problems, like arthritis and rashes)
If you’re worried you might be at risk for cataracts, talk with your doctor. Ask if there is anything you can do to lower your risk. (Cataracts | National Eye Institute (

Latest research on cataracts

Scientists are studying what causes cataracts and how we can find them earlier and treat them better. NEI also funds research on new treatment options. Get the latest news on NEI-supported cataracts research

Cortical Cataracts

Another type of age-related cataract is called cortical cataracts which appear to be like spokes of a wheel point from the outside edge of the lens toward the center. It is thought that these changes occur with age-related changes in the water content of the fibers of  the lens itself. A cortical cataract refers to white areas that develop in the lens cortex – or the “chocolate” of our peanut M&M.  This particular cataract causes problems with glare and depth perception as the spoke-like changes scatter light that enters the eye. People with diabetes are at a greater risk for developing cortical cataracts. (See Vision Changes Related to Cataracts for more information.) 
Photo of an eye with a cortical cataract. Source: National Eye Institute Photo of an eye with a cortical cataract. Source: National Eye Institute

Posterior Subcapsular Cataracts

A posterior subcapsular cataract is a small cloudy area on the back surface of our lens capsule. In our peanut M&M example, this type of cataract would be on located in the middle of the M&M’s back shell. As it is in the center of the lens, it can cause significant disturbances in vision although the cataract itself appears very small. These cataracts can develop rapidly and symptoms can become noticeable within months. Subcapsular cataracts can interfere with reading and create “halo” effects and glare around lights. Please note: A cataract is not a tumor, nor is it a “film” or tissue growth that develops over the cornea, or front surface of the eye. Although the majority of cataracts are not visible to the naked eye, there are some instances in which the pupil can appear white because the lens is completely clouded by a very dense cataract.