Cataract

Simulation photograph: normal vision Simulation photograph: cataract

What is a cataract?

A cataract is a clouding or opaque area over the lens of the eye - an area that is normally transparent. As this thickening occurs, it prevents light rays from passing through the lens and focusing on the retina - the light sensitive tissue lining located in the back of the eye. This clouding is caused when some of the protein which makes up the lens begins to clump together and interferes with vision.

Anatomy of the eye, internal
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Did you know?

The word "cataract" literally means "waterfall." For persons with an advanced cataract that covers a large portion of the eye lens, vision can be described as trying to see through a waterfall.

In its early stages, a cataract may not cause a problem. The cloudiness may affect only a small part of the lens. However, the cataract may grow larger over time and affect more of the lens, making it harder to see. As less light reaches the retina, it becomes increasingly harder to see and vision may become dull and blurry. While cataracts cannot spread from one eye to another, many persons develop cataracts in both eyes.

What are the different types of cataracts?

According to the National Eye Institute, part of the National Institutes of Health, cataract types are subdivided accordingly:

  • Age-related cataracts
    The majority of cataracts are related to aging.
  • Congenital cataracts
    Some babies are born with cataracts or develop them in childhood, often in both eyes. Some congenital cataracts do not affect vision, but others do and need to be removed.
  • Secondary cataracts
    Secondary cataracts develop primarily as a result of another disease occurrence in the body (i.e., diabetes). Secondary cataract development has also been linked to steroid use.
  • Traumatic cataracts
    Eye(s) that have sustained an injury may develop a traumatic cataract either immediately following the incident, or several years later.

Other sources, including the American Academy of Ophthalmology, describe the different types of cataracts according to the cataract location on the eye lens, including:

  • Nuclear cataract
    This is the most common type of cataract, and the most common type associated with aging. Nuclear cataracts develop in the center of the lens and can induce myopia, or nearsightedness - a temporary improvement in reading vision which is sometimes referred to as "second sight." Unfortunately, "second sight" disappears as the cataract grows.
  • Cortical cataract
    This type of cataract initially develops as wedge-shaped spokes in the cortex of the lens, with the spokes extending from the outside of the lens to the center. When these spokes reach the center of the lens they interfere with the transmission of light and cause glare and loss of contrast. This type of cataract is frequently developed in persons with diabetes, and while it usually develops slowly, it may impair both distance and near vision so significantly that surgery is often suggested at an early stage.
  • Subcapsular cataract
    A subcapsular cataract usually starts as a small opacity under the capsule, at the back of the lens. This type of cataract develops slowly and significant symptoms may not occur until the cataract is well developed. A subcapsular cataract is often found in persons with diabetes, myopia, retinitis pigmentosa, and in those taking steroids.

Why choose Weill Cornell Eye Associates?

The physicians at Weill Cornell utilize the newest methods of microsurgery, which result in cataract surgery having the highest rate of success out of all eye operations. The physicians at Weill Cornell are dedicated to patient satisfaction and after a thorough evaluation; your candidacy for the various options will be discussed.


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