What Are Cataracts?

Cloudy Lenses Occur With Aging

Updated June 2022

Have you ever tried to take a photo with a cloudy lens? When lenses are cloudy, the outcome is blurry. This can also happen to your eyes.

Your eyes have lenses too, which sit behind your corneas, the clear surface of the eyes, and your irises, the colored part of your eyes. These crystalline lenses focus light onto retina, which lines the back of your eye, enabling you to detect 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. This inhibits light from passing through your lenses, resulting in blurry vision.

“We all have a natural lens in the eye that focuses the light coming into the eye onto the retina,” explains Northwestern Medicine Ophthalmologist Jessica Minjy Kang, MD. “A cataract is a natural lens that has become cloudy and hazy.”

A cataract is a natural lens that becomes cloudy and hazy.

— Jessica Minjy Kang, MD

Understanding Causes and Symptoms

“Cataracts occur with age as protein buildup causes the lens to become cloudy,” says Dr. Kang. “It's a natural process that occurs with aging.”

Other causes of the disease include:

Long-term steroid use
Uveitis, or inflammation of the eye
Diabetes
Trauma to the eye
Smoking
Excessive exposure to sunlight
Previous eye surgery
Use of certain medications

Besides blurry vision, other 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

Approaching Treatment

“When cataracts are mild, sometimes a new glasses prescription can help correct for some of the vision changes,” explains Dr. Kang. “However, the only real treatment for cataracts is surgery to remove the hazy lens and replace it with a clear artificial lens.”

Cataract surgery is the most common treatment for cataracts and one of the most common surgeries in the U.S. More than half of all Americans ages 80 or older either have cataracts or have had surgery to get rid of cataracts. However, those with cataracts might not need surgery for months or even years, depending on the severity and progression of the disease.

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