A cataract is a clouding of the lens inside the eye. Cataracts generally occur as part of the aging process and are common. According to the American Society for Cataract and Refractive Surgery (ASCRS), more than half of all Americans over age 60 have cataracts.

Cataract Symptoms

Cataract symptoms usually occur very gradually. The primary symptoms of cataracts are:

Cataracts are painless and do not cause eye redness, itchiness, discomfort, a "scratchy" sensation or the feeling that something is "in" the eye (known as a foreign body sensation). These symptoms suggest an eye problem of some sort may exist, but they are not associated with cataracts.

Risk Factors for Cataract

No one knows for sure what causes age-related cataracts, but oxidative stress caused by unstable molecules called free radicals appears to play a significant role. Smoking and ultraviolet (UV) radiation are two sources of free radicals, and both have also been associated with a greater risk for cataracts.

Besides advancing age, smoking and long-term exposure to UV rays from the sun, other risk factors for cataract development include:

Cataract Surgery

Once a cataract occurs, it cannot be reversed. The only treatment is cataract surgery.

In cataract surgery, the cloudy natural lens is removed and replaced with an artificial intraocular lens (IOL) to restore vision. The surgery takes only about fifteen minutes and is usually performed under local anesthesia. Shortly after surgery, you can have someone drive you home that day.

When to have cataract eye surgery depends on the severity of the cataract and how much it affects your visual acuity and daily activities. If you have only a mild cataract that was detected during a routine eye exam, you may not notice any vision problems associated with it. Usually in these cases, your eye doctor will recommend monitoring the cataract with routine eye exams and will not recommend cataract surgery until the cataract worsens.

It is impossible to predict how quickly a cataract will change. Between exams, it's a good idea to check your vision one eye at a time by looking at a familiar distant object outside your home. If your vision in the eye with the cataract changes suddenly, see your eye doctor immediately to see if cataract surgery is indicated.

Choosing an Intraocular Lens (IOL)

When the time comes for cataract surgery, be aware that there are many types of intraocular lenses (IOLs) to choose from. Make sure you have adequate time to discuss your IOL options with your cataract surgeon prior to your cataract removal.

Intraocular lenses available for use in cataract surgery include:

Aspheric IOL

An aspheric IOL gradually changes in power from the center of the lens to its periphery, to more closely mimic the non-spherical shape of the eye's natural lens. Aspheric IOLs reduce a common optical error called spherical aberration and may provide sharper vision than conventional IOLs, especially in low-light situations such as night driving.

Toric IOL

A toric IOL corrects astigmatism as well as nearsightedness and farsightedness. If you have a significant amount of astigmatism prior to cataract surgery, a toric IOL may reduce your need for prescription glasses after surgery.

Accommodating IOL

An accommodating IOL has the ability to shift position slightly inside the eye in response to focusing effort, reducing your need for reading glasses after your cataract removal. Crystalens (Bausch & Lomb) is one brand of accommodating IOL used in cataract surgery.

Multifocal IOL

Multifocal IOLs have more than one lens power to help you see clearly at all distances and reduce your need for reading glasses after cataract surgery.  Brands of multifocal intraocular lenses approved for use in the United States include AcrySof IQ ReSTOR (Alcon), ReZoom (Abbott Medical Optics) and Tecnis Multifocal IOL (Abbott Medical Optics).

Cataract Surgery Recovery

Cataract surgery is safe, effective and one of the most frequently performed surgical procedures in the United States and around the world. Complications are rare, and significant complications occur in less than one percent of cataract removal procedures.

Most people recover from cataract surgery quickly and can return to their normal routine within a few days. Post-operative discomfort usually is minimal, and your cataract surgeon will prescribe medications for you to use after surgery to keep your eye comfortable and to prevent infection and inflammation during your cataract surgery recovery. Many patients see clearly the next day after their cataracts have been removed.

Cataract removal generally is performed on an outpatient basis, meaning you will go home immediately after surgery. You must have someone drive you home. Your eye will be covered with a protective shield and you will be instructed to wear the eye shield at bedtime to keep you from rubbing or bumping your eye in your sleep.

Cataract removal generally is performed on an outpatient basis, meaning you will go home immediately after surgery. You must have someone drive you home. Your eye will be covered with a protective shield and you will be instructed to wear the eye shield at bedtime to keep you from rubbing or bumping your eye in your sleep.

You may experience improved vision immediately after your cataract operation, but expect it to take six to eight weeks for your eyesight to reach its best level of visual acuity. Most people will need eyeglasses after cataract surgery for optimum vision, but many people are pleased to find they can see quite well without glasses after cataract surgery. This is particularly true among people who choose multifocal IOLs for their surgery.

Laser Eye Surgery After Cataract Surgery

In some cases, when cataract surgery does not perfectly correct a patients' vision, a laser eye surgery procedure may be used to make subtle changes in the corneal curvature. This procedure is normally performed several months after cataract surgery and is used to correct for astigmatism or myopia (nearsightedness), but not for hyperopia or presbyopia.

Cataract Surgery Risks

Though cataract surgery complications are rare, you should be fully aware of all cataract surgery risks before you sign the consent form for surgery.

Possible cataract surgery complications include:

Ask your surgeon to discuss the risk of all possible cataract surgery complications prior to surgery. Also, if you experience any sudden change in your vision or the appearance or comfort of your eye after cataract surgery, contact your eye doctor or your surgeon immediately.

Cataract Surgery Cost

Your cataract surgery cost depends on many factors, including the type of vision insurance or medical insurance you have (including Medicare), the surgeon you choose, the type of intraocular lens you choose and the amount of your post-operative care that is included in the cataract surgery fees.

Based on data from a report by leading eyecare industry analyst, the mean cost of cataract surgery performed in the United States in early 2009 (if you had no insurance and paid the entire amount yourself) was just under $3,400 per eye. If you chose cataract surgery with a premium accommodating IOL or multifocal IOL, the mean cost was approximately $4,000 per eye.

Medicare and many other insurance programs cover most of the cost associated with basic cataract surgery. But if you choose premium IOLs like those noted above, the added cost for these lenses will be an added out-of-pocket expense for you.

Also, don't forget that you may need prescription eyeglasses or at least reading glasses after cataract surgery. Check with your insurance provider to see if the cost of these glasses is covered by your policy.