What Is Cataract?

A cataract is a clouding of the lens in the eye due to protein buildup in the body which leads to reduced vision and loss of sight if left untreated. There are three primary types of cataracts: nuclear sclerotic, cortical and posterior subcapsular.

Nuclear Sclerotic Cataracts

A nuclear cataract is the most common type of cataract, beginning with a gradual hardening and yellowing of the central zone of the lens also known as the nucleus. Over time, this hardening and yellowing will expand to the other layers of the lens.

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 take several years of gradual development before it begins to affect vision.

Cortical Cataracts

A cortical cataract forms in the shell layer of the lens known as the cortex and gradually extends its “spokes” from the outside of the lens to the center. These fissures can cause the light that enters the eye to scatter, creating problems with blurred vision, glare, contrast and depth perception. People with diabetes are at risk for developing cortical cataracts.

Posterior Subcapsular Cataracts

Primarily affecting one’s reading and night vision, this type of cataract begins as a small opaque or cloudy area on the posterior (back surface) of the lens. It is called subcapsular because it forms beneath the lens capsule which is a small sac or membrane that encloses the lens and holds it in place.

Subcapsular cataracts can interfere with reading and create halo effects and glare around lights. People who use steroids or have diabetes, extreme nearsightedness, and/or retinitis pigmentosa may develop this type of cataract. Subcapsular cataracts can develop rapidly and symptoms can become noticeable within months.

There are several kinds of operations for cataracts, but they all have one thing in common: Your surgeon takes out the cloudy lens and replaces it with an artificial one.

You might feel a little uncomfortable with the idea of an operation on a sensitive spot like your eye. But it’s a very common procedure. You’ll get medicine called local anesthesia to numb your eye. You’ll be awake but sedated, and you won’t feel anything.

It usually takes about 15 to 20 minutes, and you don’t need to stay overnight in a hospital. If you have cataracts in both eyes, your doctor will wait until your first eye heals before they perform surgery on the second. More than 95% of people who have this done say they can see better afterward.

• Small-incision surgery. You may also hear your doctor call this phacoemulsification. Your surgeon makes a tiny cut on your cornea. They put a small device in your eye that gives off ultrasound waves that break up your cloudy lens. Then, they take out the pieces and put in the artificial lens.
• Large-incision surgery. This isn’t done as often, but doctors sometimes suggest it for larger cataracts that cause more vision trouble than usual. It’s sometimes called extracapsular cataract extraction. Your surgeon takes out your clouded lens in one piece and swaps it out for an artificial one. You’ll probably need a little more time to heal from this surgery than from the small-incision type.
• Femtosecond laser surgery. In this operation, your surgeon uses a laser to break up the lens. As with the other types, they’ll then put in the new lens. Your doctor may suggest this if you also have astigmatism, a curve of your cornea that makes your vision blurry. Your surgeon can treat that problem during the cataract surgery by using the laser to reshape your cornea.