A cloudiness or opacification of the lens is called a cataract. Derived from the Latin word meaning “waterfall,” the term cataract arose from the ancient misconception that cataract symptoms were caused by evil liquids that mysteriously flowed into the eye.
Ordinarily, light rays reflected from an object enter the eye through the cornea and lens, which together focus the light onto the retina to produce a sharp image. When a cataract develops, however, light rays are no longer precisely focused. Instead, the rays are scattered before reaching the retina.
However, not all cataracts affect vision significantly or require treatment. The extent of vision damage and how quickly vision becomes impaired depend on the size and density of the cataract and its location in the lens.
Cataracts can occur at any age—in fact, babies can be born with a cataract—but they are most common later in life. About 50% of people age 65 to 74 and 70% of those age 75 and older have cataracts. In 2004, an estimated 20.5 million Americans over 40 (approximately 17%) had a cataract; that number is expected to reach 30.1 million by 2020.
Cataract surgery is the most frequently performed surgery in people over age 65 and is considered by many doctors to be the most effective surgical procedure in all of medicine. About 1.5 million cataract surgeries are performed each year in the United States.
Managing Cataract Symptoms with Lifestyle Measures
Cataract surgery is considered mainly when cataract symptoms significantly interfere with important activities, such as reading or driving. Some symptoms of cataracts can be managed with lifestyle measures. These include reducing glare by wearing sunglasses and a wide-brimmed hat when outdoors; choosing the appropriate type and amount of indoor lighting; using a magnifying glass; and buying large-print reading materials. Getting a stronger prescription for eyeglasses or contact lenses sometimes can be helpful as well.
Each person has to judge how effective these steps are—and when they stop being sufficiently helpful.
When to Consider Cataract Surgery
Below are some questions to consider before deciding on cataract surgery. Answering yes to several of the questions suggests that a cataract is interfering with daily life and that cataract surgery might be beneficial.
- Am I having trouble performing my job duties because I cannot see clearly? Do I have to strain to read computer screens?
- Am I constantly squinting?
- Am I inhibited when participating in activities I enjoy—such as reading, watching television, or going out with friends—because of vision limitations?
- Do I stay in at night because of vision problems?
- Does glare from the sun or car headlights interfere with or prevent me from driving?
- Am I fearful of bumping into something or falling because of my eyesight?
- Do I need help performing daily activities—such as preparing food or doing laundry—because of my vision? Could I be more independent if my vision were improved?
- Am I becoming increasingly nearsighted? Despite frequent prescription changes, do I still have trouble seeing with my glasses or contacts?
- Does my eyesight bother me all the time?
What Cataract Surgery Entails
During cataract surgery, all or part of the eye’s natural lens is removed and replaced with an intraocular lens implant. If the eye is normal except for the cataract, surgery will improve vision in more than 95% of cases.
Because the intraocular lens implant is designed to correct nearsightedness or farsightedness, 85% of people undergoing cataract surgery achieve at least 20/40 vision—good enough to drive a car—one year after the operation. (People with 20/40 vision are able to see at 20 feet what a person with normal vision can see at 40 feet.)
After cataract surgery, however, most people will still need to wear glasses to read small print or do close handwork.
Significant postsurgical complications occur in only 1% to 2% of cataract surgery operations and include inflammation, infection, bleeding, swelling, retinal detachment, and glaucoma. People with other eye diseases and serious medical problems are most at risk for complications from cataract surgery.
Weighing the Benefits and Risks of Cataract Surgery
Immediate removal of a cataract is rarely necessary. Instead, the decision of when to have cataract surgery almost always rests with the patient. The decision is based on the cataract’s interference with day-to-day activities like reading and driving, the balance between the operation’s benefits and risks, and the presence of other health conditions that might affect the outcome.
In some cases, people with another major vision disorder, such as advanced glaucoma or age-related macular degeneration, may be discouraged from having cataract surgery because it may not improve their vision. On the other hand, cataract removal might benefit people with certain types of retinal damage. You, in consultation with your doctor, can evaluate the benefits and risks of cataract surgery for your situation and schedule elective surgery.
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Posted in Vision on November 26, 2005
Reviewed March 2010
