One thing that Mandy Patinkin knows is how to make an entrance. Striding onto the stage of Radio City Music Hall last month to present a Tony Award, the 44-year-old singer-actor sported shades huge enough to shield the entire Jackson family. But the performer quickly made it clear his attire was no theatrical ploy. "Let me explain the dark glasses," said Patinkin, who now has a recurring role as heart surgeon Jeffrey Geiger on CBS's Chicago Hope. "Eleven days ago I was lucky enough to receive a cornea transplant. Please tell your next of kin and help someone the way someone helped me."

While Patinkin's revelation came as a showstopper to most of the Tony telecast's close to 13 million viewers, family and friends were very aware of his fight for sight. Since 1982 he had been one of 133,000 Americans struggling with keratoconus, a degenerative disease in which tissue of the cornea, the clear part of the eye that allows in light, starts to thin and stretch, distorting vision. "Everything you see loses its hard edges," Patinkin explains. "It's like looking through a windshield on a stormy night without windshield wipers."

For years, despite acute sensitivity to light and occasional pain, he managed with hard contact lenses, changing his prescription as the disease progressed. But in April, Patinkin learned that he, like nearly 35,000 Americans annually, would need a corneal transplant to save his sight. On May 21 his right eye was operated on at Manhattan Eye, Ear & Throat Hospital by Sandra Belmont, a leading corneal-transplant surgeon.

Surgery to replace his other cornea, Patinkin says, will have to be juggled into a busy schedule that includes a 40-city concert tour in the fall and, of course, saving lives on Chicago Hope. Late last month the performer, who lives with his wife, actress-writer Kathryn Grody, and their sons Isaac, 14, and Gideon, 11, on Manhattan's Upper West Side, spoke to correspondent Anthony Duignan-Cabrera about how corneal transplant has altered his outlook.

SUDDENLY I COULDN'T SEE ANYTHING. It happened in Los Angeles on April 30, the day I finished shooting the season finale of Chicago Hope. I came out of the studio, and the light was so bright, and my eyes were so sensitive, that I had to cup my hands over them for about a half hour to let them calm down. It felt like a terrible burning in my eyes and a piercing pain at my temples. Later that evening, as I was coming back from dinner, my eyes were still very sensitive. I was driving down Ventura Boulevard, and something, maybe a speck of dust, got under my contact lens. It felt like there was acid in my eyes.

Both my eyes slammed shut; I couldn't open them. I was in the dark, trying to find the switch for the hazard lights in a rental car—good luck!—and I hit the brakes and started praying that no one would hit me from behind. Luckily it was around 11 or 12 at night, and there wasn't a lot of traffic. But it took me about 10 minutes before I could pull over. I was sitting there that long with my eyes closed in the middle of the traffic lanes. Finally I pulled over, and I sat there for a half hour to let my eyes calm down. Then I drove home.

I figured I needed to get new contact lenses. But when I returned to New York, all my doctor said to me was, "It's time to think about a corneal-transplant operation." I was stunned—this had not been on my game plan. But he argued my life was becoming more difficult; I'd almost killed myself driving. No matter what I would do with the contacts, it was getting harder and harder to get the balance right, to see up close and at a distance, and it was becoming more difficult to tolerate the lenses.

The good news, he said, was that the operation would improve the quality of my life 100 percent; there would be no more contact lenses and, in some cases, people who had the operation didn't even need reading glasses. But most important of all, he said it was better to do this while I was still relatively young because the disease gets progressively worse. He sold me right there.

I went for tests that very same day, and the cornea of my right eye was more severely affected. On May 20 I received a call that the cornea of an adolescent male had become available, and that I should go to the hospital the next day for the transplant. The surgeon, Dr. Sandra Belmont, wanted a young cornea for me. You can use a cornea from a 2-year-old up to a 75-year-old, but you wouldn't want to put a 75-year-old cornea in a 40-year-old.

The operation involves removing the diseased cornea and replacing it with a healthy one. A lot of people get a general anesthetic because they want to be out. But as a singer I didn't want a general, because for one out of 200 people who get general anesthetic, there can be damage to the vocal cords when they remove the breathing tube. I was heavily sedated intravenously because I didn't want to feel the needle go into my eye.

The next thing I knew I woke up in another room. It was over. I had a bandage over my eye, and I went home—just four hours after I had arrived at the hospital. The next day in Dr. Belmont's office she took off the bandage. I was able to see immediately with my right eye. I could see better than I had for 15 years without contacts. It was unbelievable.

If my family was worried, they never let on. They were like a cheerleader section. Everyone was extremely positive. When I was having pain post-surgery with light, and when it just hurt, they were very good. For a few days they left me alone to just lie down and close my eyes if I needed. When I started going out again, later that week, it was difficult to deal with bright light. I needed two pairs of sunglasses plus a baseball cap to keep the glare down. But after about 2½ weeks, the daylight stopped being so painful.

A week after the operation, the producer of the Tonys called and asked me to be a presenter. I told him that I just had this operation. I had to wear these dark glasses, and I couldn't read, and I couldn't see very well. But then I remembered, after the operation, the doctors at the eye bank said to me, "We hope that you will want to talk about it a little because of your access to the public. We've had a few celebrities who have had this corneal transplant, and they won't talk about it." At first I didn't understand, but then I found out that some of them were frightened about not getting work, of not getting insurance and about how they would be perceived. I guess it's like cancer in the old days. If you mention you have a disease, people get nervous. But for me this was never a disease I hid.

I learned that the need for corneas is very great and the need for the public awareness was just as important. So I asked the producer if I could talk about the transplant. I did, and I said how great the need was. I was amazed by the phenomenal response I received. I realized that my experience touched more than just people who suffer from keratoconus.

I received a letter from a 6-year-old boy thanking me and hoping my eyes would get better. His mother also wrote, thanking me for my plea for donors because her son was born with a congenital heart defect and needs a heart transplant. She wrote that a doctor told her that fewer than 5 percent of the U.S. population have registered as organ donors and she fears there might not be a heart available when it comes time for her son's transplant. It's really important to fill out organ-donor cards and register with organ banks, but the most important thing is to tell your next of kin. I'm glad I got the disease, I really am, because now I can help people. I will work until the day I die to help others get the same gift.

I would have gone blind, but now I won't because this child gave me the gift of his cornea. I often think, "Who was he? What did he see?" It's hard to put it into words, but I often think I'm not looking through my own eyes; I'm seeing with a child's eye. I will say a prayer for him every day for the rest of my life.