Cataract

A cataract is a dense, cloudy area that forms in the lens of the eye. A cataract begins when proteins in the eye form clumps that prevent the lens from sending clear images to the retina. The retina works by converting the light that comes through the lens into signals. It sends the signals to the optic nerve, which carries them to the brain.

It develops slowly and eventually interferes with your vision. You might end up with cataracts in both eyes, but they usually don’t form at the same time. Cataracts are common in older people. Over half of people in the United States have cataracts or have undergone cataract surgery by the time they’re 80 years old, according to the National Eye Institute.

There are several underlying causes of cataracts. These include:

• An overproduction of oxidants, which are oxygen molecules that have been chemically altered due to normal daily life
• Smoking
• Ultraviolet radiation
• The long-term use of steroids and other medications
• Certain diseases, such as diabetes
• Trauma
• Radiation therapy

There are different types of cataracts. They’re classified based on where and how they develop in your eye.

• Nuclear cataracts form in the middle of the lens and cause the nucleus, or the center, to become yellow or brown.
• Cortical cataracts are wedge-shaped and form around the edges of the nucleus.
• Posterior capsular cataracts form faster than the other two types and affect the back of the lens.
• Congenital cataracts, which are present at birth or form during a baby’s first year, are less common than age-related cataracts.
• Secondary cataracts are caused by disease or medications.
• Traumatic cataracts develop after an injury to the eye.
• Radiation cataracts can form after a person undergoes radiation treatment for cancer.

Your doctor will perform a comprehensive eye exam to check for cataracts and to assess your vision. This will include an eye chart test to check your vision at different distances and tonometry to measure your eye pressure. The most common tonometry test uses a painless puff of air to flatten your cornea and test your eye pressure. Your doctor will also put drops in your eyes to make your pupils bigger. This makes it easier to check the optic nerve and retina at the back of your eye for damage. Other tests your doctor might perform include checking your sensitivity to glare and your perception of colours.

If you’re unable or uninterested in surgery, your doctor may be able to help you manage your symptoms. They may suggest stronger eyeglasses, magnifying lenses, or sunglasses with an anti-glare coating.

Surgery:

Surgery is recommended when cataracts prevent you from going about your daily activities, such as reading or driving. It’s also performed when cataracts interfere with the treatment of other eye problems. One surgical method, known as phacoemulsification, involves the use of ultrasound waves to break the lens apart and remove the pieces. Extracapsular surgery involves removing the cloudy part of the lens through a long incision in the cornea. After surgery, an artificial intraocular lens is placed where the natural lens was. Surgery to remove a cataract is generally very safe and has a high success rate. Most people can go home the same day as their surgery.