When Dr. Oz's wife, Lisa, went in for corrective eye surgery, he says she was the victim of a medical error. "They set the device for her right eye and put it on her left eye," he says. "[It] almost blinded her."

One way a patient can prevent this kind of "wrong-site surgery" error is a simple as writing a note. "If you're going to have surgery on your left arm, write 'Operate on this arm' [on your left arm]," Dr. Oz says.

Don't distract your doctor