During her stint as a Navy ocean systems technician, Brenda Ross ripped four tendons off her right kneecap and spent months in painful recovery in hospitals in Iceland and the United States. She was married in a wheelchair wearing a pair of her husband's sweatpants, and spent the next five years struggling with knee pain and learning to lose her limp. But that injury now seems to Ross like a sunny stroll on the beach compared to her collision with LASIK vision-enhancement surgery.

In 1999, during a procedure to correct her nearsightedness, an eye surgeon cut and lasered too deeply into the 37-year-old's right eye. Recognizing his error, the doctor stopped the surgery before touching the other eye. "LASIK left a hole in the back of my cornea," said Ross, a mother of four. "I've had injuries in the past, but none of them affected me like this one."

Surgery had turned her world into a blurry, warped collage. "If somebody was standing in front of a light source, whatever was in the background behind them would end up looking like it was on top of them." Not only was there distortion, but Ross saw a veiny veil over everything, as if she were seeing her own eyelid. To make matters worse, she said, her surgeon was completely unreceptive to her plight. She recalls him saying, "I don't see what your problem is; people drive with one eye every day."

Over the next year, the Oregon resident visited five different ophthalmologists searching for answers. It wasn't until she traveled to the San Ramon office of Arthur Ginsburg, director of Vision Sciences Research Corporation and Visual Forensics Corporation, that she began to understand what had happened to her. At his office, Ross went through hours of exams to measure her impairments. "My surgeon had hidden a lot of the truth," she said. "When I went down to see Dr. Ginsburg, there were several things he was able to explain to me. He was the most informative person I have spoken to. ... He's just a wonderful, amazing man."

A meticulous scientist who has devoted much of his career to vision research, the Cambridge-trained doctor of biophysics has invented a test that goes beyond the eye chart and measures "contrast sensitivity" -- for example, how well someone can distinguish shades of gray in a dimly lit setting. "With each group of tests he would explain more and more about my vision," Ross recalled.

When the surgery cut deeper than it should have, fluid in her eye leaked and caused a bulge inside. Ginsburg explained that this had thrown a permanent wrench into her central optical axis. To make matters worse, it was in her dominant eye, which made it impossible for her to ignore the distorted input.

But because her brother had already undergone successful laser vision correction in both eyes, Ross found it tough to convince her family and friends how horrific her own sight had become. "I was becoming so terribly depressed and giving up all hope," she recently recalled. "When I finally saw Dr. Ginsburg, he put that spark of hope back in, not that I was going to find a cure necessarily, but that this wasn't all in my head, that I wasn't making this up. ... I felt like 'Oh my gosh, I'm being validated. For once, somebody understands.'"

Ginsburg gave Ross several computer simulations to take home so her family and friends could experience the world she was seeing. Upon seeing those pictures, their typical response was: "How do you even function?"

When laser vision-correction surgery doesn't deliver the promised results, the impact can be profound. Ross is one of tens of thousands of patients whose lives have been turned upside down due to improper risk screening, malfunctioning machines, or shabby surgical techniques. Instead of the carefree new lifestyle these patients anticipated, they have received an involuntary lifetime admission ticket to their own personal laser light show. At best, they face glare, halos, starbursts, multiple images, or poor depth perception. At worst, they face chronic pain, corneal transplants -- even blindness in rare cases. For those already damaged, the road to rehabilitation is frustrating and slow, and sometimes the only good remedy is an entirely new pair of eyes.

Laser eye surgery is the most popular elective surgery in the United States today. Data provided by the American Academy of Ophthalmology indicates that approximately 2.5 million American patients had undergone LASIK by the end of 2002. According to a recent survey conducted for American Demographics magazine, 30 percent of all Americans would like to have the surgery.

By all accounts, the majority of patients enjoy successful surgery. Data from the 9,000-member American Society of Cataract and Refractive Surgery suggests that LASIK surgeries are successful 97 percent of the time. But transcripts of US Food and Drug Administration proceedings suggest that failure may be much more widespread. In August 2002, discussion by the members of the FDA's Ophthalmic Devices Panel indicated that 10 percent of clinical study patients have been consistently unsatisfied with their laser-based refractive surgeries. The panel also admitted that one patient in five will have a tougher time seeing in dim lighting -- the dimension of vision that Ginsburg's innovative new test examines.

Depending on which satisfaction estimate one accepts, somewhere between 75,000 and 250,000 people so far have left their eye surgeon's office with considerably less eyesight than they had when they first walked in.