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What Are Cataracts?

Cloudy Lenses Occur With Aging

Have you ever tried to take a photo with a cloudy lens? The outcome is blurry. That same phenomenon is how cataracts affect vision.

Your eyes have lenses too, which sit behind your corneas and your irises, the colored part of your eyes. These crystalline lenses focus light onto the back of your eye, or the retina, so that you can make out shapes. The lenses of the eyes are made up of protein fibers and water. Over time, abnormal proteins build up on the lens and create cataracts, which inhibit light from passing through your lenses. This results in blurry vision.

“Because cataracts are caused by a buildup of cloudy proteins in the lens over time, they are commonly associated with aging,” says Northwestern Medicine Ophthalmologist Anupama R. Anchala, MD. In fact, roughly half of people over the age of 65 in the U.S. have cataracts, and cataracts are one of the most common diseases in the world, says Dr. Anchala. In rare instances, babies can also be born with cataracts, she adds.

Other causes

  • Long-term steroid use
  • Uveitis, or inflammation of the eye
  • Diabetes
  • Trauma to the eye
  • Smoking
  • Excessive exposure to sunlight
  • Previous eye surgery
  • Living at a high altitude
  • Certain medications

Apart from blurry vision, symptoms of cataracts may include:

  • Glare or seeing halos around lights, especially at night
  • Gradual clouding of vision
  • Frequent glasses prescription changes
  • Developing more nearsighted vision

“It’s important to note that these changes to vision happen gradually with cataracts, and there is typically no pain associated with them,” says Dr. Anchala. “When diagnosing cataracts, I ask patients for a detailed history of their vision, along with a regular examination. If their symptoms develop over a longer timeline, they may be consistent with cataracts.”

Types of cataracts

Nuclear sclerotic cataracts are age-related, caused by the hardening of the lens overtime. They’re the most common type of cataracts.

Cortical cataracts arise more from changes in the water content of the lens and are more common in people who have diabetes or excessive sun exposure.

Posterior subcapsular cataracts occur on the back side of the lens. The most common symptom with this type of cataract is seeing a glare or halo around lights. People who use steroids or who have diabetes or certain eye diseases such as retinitis pigmentosa are more likely to develop this type of cataract.

Treatment for Cataracts

Surgery is the most common mode of treatment, and is one of the most commonly performed surgeries in the U.S., but “people can develop cataracts and not need surgery for months or years,” says Dr. Anchala. “We remove cataracts when they start interfering with daily activities like reading and driving, but the surgery is not emergent.”

If you believe you have cataracts, consult with your primary care physician or see an ophthalmologist for a diagnosis and appropriate treatment plan.