Holy smokes!"
Those were the words that came to mind—although I could have cried out something much stronger. I was in the San Francisco office of a doctor who had been working to restore vision to my right eye. I was there for a routine checkup. But when he unwrapped my bandages—suddenly there was this whooosh of light.

That day, March 7, 2000, was the beginning of a journey that hasn't ended yet. I had been blind for 43 years, since an accident when I was 3. Now coming across the room toward me was my wife, Jennifer, my soulmate of 16 years. I had always heard about her blue eyes and blonde hair. Now I could see them, and she was beautiful, just like I knew she was. It was, well, amazing.

Being blind, at least for me, was not what people think it is. I could always dimly perceive some light and movement with my right eye (I lost the left one to an infection after the accident). It was kind of like looking through a windshield that's completely iced over. But now I could truly see. At first it was a shock. Then my curiosity kicked in. I was fascinated by the picture on the wall of the doctor's office that day in San Francisco. Seeing the cars whiz by on the ride home to Davis, where Jennifer and I live with our two boys, Carson, 11, and Wyndham, 9, I thought these big metal blobs might crash into us. And trees. I had experienced them before—touched them, smelled them—but I never knew they were so tall. Or so awesome.

Those first weeks were an incredible series of firsts. My first airplane flight, for instance. It was a very bumpy ride, and for 30 minutes I kept busy working on my computer. Then I looked out the window and I could see the ground. I was so excited I turned to the lady next to me and said, "Excuse me, I got my sight back last week after being totally blind for 43 years. Could you help me figure out what I'm seeing?" There was a big pause as she decided whether I was a lunatic or a miracle. A few months later, after going skiing with my sons—something I had done before, but with the help of a guide—I made the mistake of gushing to a stranger on the chairlift, "That was like having sex with the lights on!"

But life after the operation hasn't always been miraculous. My vision is now officially 20/1000, meaning my remaining eye can see an upheld finger from about five feet away. What the doctors studying my progress have discovered, however, is that "seeing" is more than seeing. There are parts of my brain that cannot process what my eye is seeing. When most people say "bookcase," they immediately picture a bookcase. I need to see something for the 10th time before it sinks in what it is. It's like learning a language: You have to build up the vocabulary.

I always felt I had become a pretty good blind guy. I went to college and started my own company. I met Jennifer, now 46, on a ski slope in Kirkwood, Calif., where she was a volunteer guide for the Discovery Blind Sports program, and we have two beautiful sons. In 1983 I even jumped out of an airplane with a parachute.

So when Daniel Goodman, the partner of Jennifer's eye doctor, first told me about a new way to regenerate damaged corneas using stem cells [see box], I wasn't so sure about having the operation. As a kid, I had four cornea operations that failed. I hated hospitals and anesthesia. Still, I thought about it for about nine months. The doctors kept my expectations very low. They told me that this may not work at all, or that I would have some sight and then maybe lose it. It came down to how I think of myself. Who is Mike May? I decided I was an adventurous person who's willing to try anything. I never wanted to wonder, "What if?"

It took two operations, and I had bandages on my eye for just a few days after each. At first, some things were almost too much to take in all at once. Our town hosts a Picnic Day parade every spring, and I went with Carson and Wyndham. I'd never known music as anything but auditory and yet, an arm's reach away, a marching band was moving in patterns I couldn't follow, their instruments and uniforms flashing in the sun. It all fit together perfectly, the sounds and sights. Tears ran down my face.

Seeing fireworks for the first time was actually a little strange. I've never been a big fan of loud explosions, ever since the accident that made me blind. But I couldn't tear myself away from the star patterns and raining lights and bursts of color. When it was over, I felt giddy but also glad I could close my eyes and talk and think without looking. Probably the biggest deal, though, is being able to play ball with my boys.

Less than a year after the transplant, I went in for a routine checkup. Dr. Goodman looked into my eye and said, "Mike, we have vigorous rejection going on." I knew from the start there was a chance my body would reject the new cornea I had received, and I was taking drugs to help prevent that from happening. My son Carson wanted to know if the eye rejects, do I get my money back? We laughed. It took nearly 10 months on medication—and injections to my eyeball—but eventually the problem cleared up. My doctors told me my visual acuity had remained stable, but I'm quite sure my speed in processing visual information actually improved.

Jennifer laughs at how I can now sort the laundry colors properly. I used to throw them all in together and wash them on the warm cycle. Invariably, we would end up with pink undershirts. Now it's separate white and color loads. Life is good! The last few years haven't always been fun—having your eyelashes singed off so they don't get in your eye and damage it, and a needle stuck in your eye is a big ouch. And I still close my eyes sometimes when what I'm seeing becomes too distracting. But it's been worth it, an incredible journey. I know that my sight will not improve much more, which I accept. And I may well lose sight entirely one day. But I'm glad to have gotten this much. Sight hasn't changed my life, but it has enriched it. Life is a challenge—and a gift. Sight, for me, is something extra.

As told to Maureen Harrington