Fifteen months ago Chris Downey was just another green architect, based in Oakland. Now he has an expertise that separates him from every other architect in the Bay Area and all 20,000 attendees at this week's American Institute of Architects' National Convention in San Francisco.

Downey, 46, is a blind architect dedicated to planning buildings for blind people, a niche brought about by his sudden loss of sight after surgery.

"It is actually pretty exciting," says Downey, as he sits in a drafting room, like everybody else at SmithGroup Inc. in the Financial District. Then he rises to 6 feet 4, grabs a white cane with one hand and reaches out with the other, grasping for something to shake. "For someone who likes problem solving, this is quite a challenge," says Downey, who has been working up floor plans in braille to submit to blind clients overseeing the design of a new blind rehab center at the Veterans Affairs center in Palo Alto.

"It's a question of how do you design an environment for people that aren't going to see it?" Right. But there is one question before that. As he puts it, "Blind architect. What a preposterous idea. How does that work?"

The answer starts with a benign tumor that had slowly encircled the intersection of optic nerves. The tumor began to push the nerves out of position, and that's when Downey couldn't follow the flight of a baseball as he played catch with his son, Renzo, now 11, at home in Piedmont. Next Downey was hitting stuff in the road, during the 100 miles he'd do weekly on his bicycle. Still, he could get his work done with the aid of glasses. His eyeballs looked fine, but an MRI revealed a non-malignant golf-ball-size growth causing the blind spots.

"If it weren't for playing baseball with my son and riding my bike, who knows when I would have figured it out," he says.

Because of the tumor's proximity to the optic nerve, radiation treatment to shrink it was not an option. He had surgery on St. Patrick's Day 2008 to try to correct his vision, even though he was aware that it was risky and might not work.

Downey's father, a physician, had died of complications from brain surgery at 36, so waking up after the procedure at all made Downey feel "pretty darn lucky." Luckier still that he had blurry vision, as expected. "It was amazing," he recalls. "It was a 9 1/2-hour procedure, and the next day I was up walking around."

When he awoke on the second day, his field of vision had been cut in half horizontally, as if the water were at eye level in a swimming pool. By the third day he'd lost vision in the top half, too. It varied from dark to light for five days, then it faded to black.

"I lost my sight," says Downey, who knew going in that this was a risk. "But I came out pretty darn healthy, with the exception of the sight."

He accepted blindness right away. What he could not accept was the advice of a social worker who came in and immediately started discussing a career change. Every step he had taken since junior high in Raleigh, N.C., had been toward becoming an architect. He had seven years of schooling into it, topped by a master's degree from UC Berkeley in 1992. Since then, he had designed aquariums, libraries, theaters, stores and homes.

He tried returning to the job he'd started a few months before he became ill, but was laid off before Christmas. He searched the Internet, and found one blind architect in Lisbon, Portugal, and a guy who works as a forensic architect, investigating failures in buildings. That was it.

On a whim he called Patrick Bell, a business adviser to architecture firms, and that's when Downey finally got some decent Irish luck. As it happened, Bell was working with a firm called the Design Partnership, which is doing a joint venture with SmithGroup to design a 170,000-square-foot Polytrauma and Blind Rehabilitation Center for the Veterans Administration Palo Alto Health Care System. Bell made the connection, and Downey was hired as a contract architect.

"It's the first time any of us have dealt with even a sight-impaired architect, let alone one who is blind," says Kerri Childress, VA spokeswoman. "It's really been beneficial having an architect who is blind working on a facility to serve the blind."

The design phase runs through July. From there, Downey has been invited to serve as a mentor to blind high school students at a weeklong event this summer in Maryland. (He's also back to cycling on a tandem bike with his buddy steering, and is up to 60 miles in the Oakland hills.) And he wouldn't mind addressing next year's AIA convention in Miami.

"I was always nervous in front of crowds," says Downey, "but now that I can't see them, I think it will make it easier."