Cataracts

Image of the eyeWhat is a cataract?

A cataract is a clouding of a lens in an eye. It can affect one or both eyes and most often happens in older people. In fact, more than half of Americans age 80 and older have a cataract or had cataract surgery.

How does a cataract develop?

The lens of each eye needs to be clear in order for light to pass through on its way to the retina. The lens focuses incoming light. Once light reaches the retina, it is changed into nerve signals that are sent to your brain, which processes the signals into images you see. In a cataract, proteins in the lens may clump together and cloud a small area. That cloudy area may get bigger. Light coming through a lens clouded by cataracts will result in blurry images. 

Image viewed by a person with normal vision    Image as viewed by a cataract person

What causes cataracts?

Age, smoking, and diabetes are the leading causes of cataracts. Prolonged exposure to ultraviolet sunlight and a family history of cataracts may also increase risk. Cataracts may also develop after eye surgery or an eye injury.

How would I know if I had a cataract?

Symptoms of cataracts include:

  • Cloudy or blurry vision
  • Seeing faded colors
  • Glare, with headlights, lamp, or sunlight appearing too bright
  • Seeing a halo around lights
  • Worse vision at night
  • Double vision/seeing multiple images
  • Having to change your eyeglass or contact lens prescription often

The best way to know if your symptoms are due to cataracts is to see an eye care professional for a vision test and comprehensive dilated eye exam.

How are cataracts treated?

Vision impaired by early cataracts may improve with new glasses, antiglare sunglasses, magnifying lenses, or brighter lighting. If those approaches are not enough to improve your vision, you may need surgery to remove the cloudy lens and replace it with an artificial lens. If you need surgery in both eyes, they are usually done separately, about four weeks apart. The operation takes less than an hour and is almost painless. Most people who have the surgery have better vision afterward.