Aging eyes and cataracts

A cataract is a clouding of a clear lens within the eye that blocks the passage of light needed for vision.

What are cateracts?

Cataracts form slowly and cause no pain. Some stay small and hardly affect vision, but if the cataract increases and begins to affect vision, it can usually be removed surgically.

"While cataracts are one of the world's leading causes of blindness, vision loss from cataracts is reversible in most cases," says Tom Oetting, MD, associate professor of ophthalmology and visual sciences at University of Iowa Hospitals & Clinics. "New techniques developed over the past decade have made cataract surgery one of the most successful procedures available for restoring quality of life to patients."

Tim Johnson, MD, PhD, clinical professor of ophthalmology and visual sciences, says cataracts cannot be made to disappear with drugs or exercises.

"Cataract surgery is most often performed as an outpatient procedure under local anesthesia," Johnson says. "The cloudy natural lens can be replaced with a clear artificial lens to give the eye proper focusing power. In most cases, the improvement in the patient's vision is profound."

How does a person know if they have a cataract?

Cataract symptoms

  • Gradual painless blurring of vision
  •  Double vision in one eye
  • Fading or yellowing of colors

"When my older patients mention sensitivity to glare and/or bright light or trouble driving at night, I suspect a cataract," he says.

Johnson dispels the notion that a cataract has to be "ripe" before it's removed. The best time to have a cataract removed is when it starts to interfere with the things you like to do, he says.

"Cataract surgery is a great procedure, but it is still surgery," Johnson says. "If cataracts don't affect your quality of life, you may feel that surgery is not needed. The only person who can really decide when it's time to have it removed is you."

Cataracts quiz for those over age 40

  • Do you have trouble reading highway signs, particularly on bright days?
  • Is your distance vision blurry, especially outdoors?
  • Is it difficult to discern the edges of stairs or curbs?

Cataract risk factors

  • Cigarette smoking
  • Diabetes Mellitus
  • High cholesterol/triglycerides
  • Steroid medication
  • Excessive exposure to sunlight
  • Eye injury
Last reviewed: 
June 2017

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