Cataract Surgery
Safety and Risks

Cataract Surgery Risks

The fact that millions of people have gone before you and come out of the procedures pleased, healthy, and able to see clearly again should be of comfort. Nonetheless, there are always special cases and certain situations when complications can arise.

No surgical procedure is without risks. The following list, while not comprehensive, provides some of the potential complications which could occur. These may develop during or after cataract surgery while you are still under your doctor's care and would be addressed immediately.

Bleeding. Bleeding inside the eye during cataract surgery is extremely rare, because the incision is placed on the edge of the cornea,   Cornea: The clear, curved surface at the front of the eye through which light enters the eye. Along with the sclera, the cornea provides external protection for the eye.   which contains no blood vessels. If it does occur, it will likely occur on the surface of the eye. In this case, the surgeon will usually cauterize the area and the bleeding stops.

Bruising or black eye. If your doctor used an injection to numb your eye, it is possible that you may experience some bruising around your eye. This is temporary and will go away on its own.

Incision leak. Sometimes a small leak in the incision in the cornea can occur. Such a leak increases the chances of infection, and your doctor may apply a contact lens or pressure bandage over your eye to decrease the chance of infection. In some cases, the incision must be closed with a stitch.

Intraocular Infection. Developing an infection after cataract surgery is extremely rare, occurring only once in several thousand surgeries.1 Most cataract surgeons administer antibiotic drops before, during, and after surgery to minimize the risk. Endophthalmitis, an inflammation of the eye triggered by infection, is also very rare and more common in people with compromised immune systems, which includes patients with diabetes. For tips on managing diabetes, click here.

Inflammation. Swelling inside the eye that is unrelated to infection is usually minor and can easily be treated with anti-inflammatory drops after surgery.

Glaucoma. An extremely small number of cataract surgery patients develop secondary glaucoma after cataract surgery. Secondary glaucoma is usually temporary and can develop when inflammation or bleeding occurs during the surgery. In most cases, glaucoma medications can be used to help control the increased intraocular pressure, but sometimes, laser or other surgery is required.

Pronounced astigmatism. Sometimes swelling of the cornea or tight stitches (if stitches are used) can distort the shape of the cornea, causing astigmatism. Swelling will reduce during healing, and the astigmatism will generally go away on its own. Or if stitches were used, once they are removed, the cornea will usually relax back to its natural shape.

Retinal detachment. If you are extremely nearsighted, you may be more prone to retinal detachment during cataract or any other eye surgery. Symptoms include flashing lights, new floaters, gradual shading of vision as though a curtain was being drawn, and quick detachment of your sharp, central vision. If you experience any of these symptoms, call your doctor immediately.

Tearing of the posterior capsule. During cataract surgery, the natural lens is removed from the posterior capsule and replaced with an artificial IOL. The capsule can sometimes tear during this process. When this happens, the physician will repair the vitreous body that has leaked into the capsular bag   Capsular bag: A thin membrane that holds the eye's natural lens.   and seal it off.

Decentered intraocular lens. Rarely, the IOL placed in the eye can become displaced a week to a month later. If this happens, you would experience blurred vision, glare, double vision, or fluctuating vision (when the eye sees the edge of the IOL, causing focused and unfocused images). This is sometimes due to torn zonules   Zonules: Ligaments in the eye that connect the capsular bag to the muscles in the ciliary body.   during surgery or through an accident involving the eye. Your doctor will either reposition the lens or remove and replace it with another.

Cystoid macular edema.   Edema: The swelling of (eye) tissues from excess fluid accumulation.   As long as 3 months after cataract surgery, or as soon as a few weeks, the tissues of the macula   Macula: The center-most portion of the retina responsible for central vision and the seeing of fine detail.   may swell. If this happens, your central vision will be blurry, and your doctor will most likely give you a non-steroidal anti-inflammatory drug.

Secondary cataract. Occurring after about 30 percent of surgeries,1 a secondary cataract happens when cells have grown under the lens and the posterior capsule holding the IOL has become cloudy, blurring your vision. Your doctor will then use a YAG laser to create a small hole in the membrane for light to pass through. This is a painless outpatient procedure your doctor can perform quickly.

Other adverse reactions that have been associated with the implantation of intraocular lenses are: hypopyon, acute corneal decompensation, pupillary block, and secondary surgical intervention (including but not limited to lens repositioning, biometry error, visual disturbances or patient dissatisfaction). As a result of the multifocality, some visual effects (halos or radial lines around point sources of light at night) may also be expected due to the superposition of focused and unfocused multiple images. A reduction in contrast sensitivity may also be experienced by some patients, especially in low lighting conditions such as driving at night.

For more information, please read the Safety Information for AcrySof® IQ ReSTOR® IOL and AcrySof® IQ Toric IOL.

Cataract Surgery Safety

Cataract surgery is considered one of the most effective medical procedures today. In fact, more than 3 million cataract surgeries are performed each year in the United States alone, with more than 971 percent of first-time cataract procedures considered "successes," meaning no complications. Modern advances, such as the LenSx® Laser, may also improve outcomes.

Additionally, about 95 percent1 of patients are able to restore their vision to their pre-cataract state after undergoing the standard intraocular lens (IOL)   Intraocular lens (IOL): An artificial lens made of plastic, silicone, or acrylic, which is designed to be implanted in the eye to improve its focus and correct vision problems related to cataracts.   procedure. That's an incredible success rate!

Most people experience no pain or discomfort during the procedure, which lasts just 15 to 30 minutes and, thanks to recent advancements, general anesthesia isn’t even necessary, simply a topical anesthetic.

For more about cataract surgery—including how safe and sterile each operating room must be—read What to Expect During Cataract Surgery.

Next: Cataract Surgeons


  1. "The Aging Eye: A Special Health Report from Harvard Medical School," Ed. Fine, Laura C., M.D, and Heier, Jeffrey S., M.D., copyright 2006, Harvard Health Publications, Boston, MA.