[Need this info in Spanish? See Cataratas.]

A cataract is a clouding over of the lens inside the eye, which is located directly behind the pupil and the colored iris that surrounds the pupil. The lens, along with the cornea (the clear front surface of the eye), is responsible for focusing light onto the retina, which is the first step the visual process.

Most cataracts are age-related, and the risk for cataracts increases with advancing age. LASIK and other laser vision correction surgery does not increase (nor decrease) your chance of getting cataracts.

The development of cataracts appears to be associated with oxidation of proteins in the lens. These changes to lens proteins cause the lens to become cloudy, reducing its ability to focus light. The underlying reason for these lens changes is unknown, but risk factors include poor nutrition, excessive exposure to UV radiation from sunlight, cigarette smoking and drinking too much alcohol.

Symptoms of cataracts include glare and halos around lights (especially when driving at night), blurred or distorted vision, and reduced color vision. Cataracts do not cause eye pain or discomfort.

The best way to determine if you have cataracts is to have a comprehensive eye exam. Your eye doctor will dilate your pupil, which enables him or her to see the entire lens and evaluate whether any clouding is taking place.

If a cataract is present, your eye doctor generally will monitor its progression with routine exams and advise you when cataract surgery is needed.

Cataract Surgery

There are two steps to modern cataract eye surgery: cataract removal and IOL implantation. See a cataract surgery video.

In the cataract removal step, the surgeon inserts an ultrasonic probe through a small incision in the front of the eye and uses this device to break up the cloudy lens into small pieces. This process, called phacoemulsification, allows the surgeon to remove the cataract from the eye through a much smaller incision than what would be needed without "phaco."

After all of the cataract and other lens material is gently removed with suction, the surgeon then implants a clear intraocular lens (IOL) in the eye to restore vision. Prior to surgery, eye measurements are taken to help the surgeon choose an IOL power that limits how much nearsightedness, farsightedness or astigmatism remains after your cataract operation.

Cataract Surgery That Fixes Presbyopia, Too

Premium multifocal and accommodating IOLs (such as Crystalens) are available to address presbyopia and help restore good vision at all distances, thereby reducing the need for bifocals or reading glasses after cataract surgery.

LASIK or other laser vision correction surgery does not decrease your odds of having safe and effective cataract surgery. But because refractive surgery alters the shape of your eye, it can make choosing the proper IOL power more challenging for the cataract surgeon. If you are unhappy with your vision after cataract surgery because of residual refractive error, an additional refractive surgery can be performed to reduce your need for eyeglasses.

Cataract surgery generally is very safe and effective, and most people are very pleased with their outcome. Choosing an experienced and respected cataract surgeon can increase your satisfaction with the procedure. Also, to insure a speedy recovery from your cataract surgery, be sure to carefully follow all post-operative instructions your surgeon gives you.

Though most premium IOLs used in modern cataract surgery provide protection from the sun's ultraviolet (UV) rays, it's a good idea to wear quality sunglasses after cataract surgery to reduce glare and eye fatigue when outdoors. Choose sunglasses that block 100 percent UV to protect your eyes and the delicate skin around them from sun damage.