Photographs by Michael Appleton for The New York Times

It takes chutzpah to master the art of cycling in New York City. Doing it on a tandem bicycle — known, more romantically, as a bicycle built for two — is harder. Doing it when you can’t see where you’re going, though, is a different story altogether.

“It’s a little bit of an obstacle course,” Stephen Pearlman called over his shoulder from the front of a tandem bike spinning down a path along the East River. I was pedaling in the back seat, blinded by a pair of dark goggles.

“There’s a gate coming up, which is just, like, an entrance to Carl Schurz Park,” he continued. “It’s very pretty — flowers. We have the East River on the right. People sitting on benches here, dogs.”

The bike was moving a little too fast.

“Let’s glide now,” Mr. Pearlman said.

For some cyclists, though, riding without sight is not a choice; it’s a fact. There are dozens of blind and vision-impaired tandem-bike riders in the city, and on Friday six of them, paired with sighted partners, are running a 24-hour, five-borough bike relay.

The event, “Double Up For Vision,” is a fund-raiser for Lighthouse International, a nonprofit advocacy group for people dealing with vision loss and blindness. The relay starts at Lighthouse’s headquarters on East 59th Street and swings through Flushing, Coney Island, St. George on Staten Island, then up into the Bronx and back to Riverside Park.

For the captain of a tandem bike, who rides in front, the experience is not just about steering; it is about verbalizing the surroundings. The stoker, or second rider, gets to live that description, augmented by other senses.

“When you’re in a car,” said Artie Elefant, 65, a legally blind rider, “you’re isolated. You don’t feel anything. But on a bike, you feel the wind on your face. You start to feel what the road is like, the terrain, the up-and-down.”

Mr. Elefant was born seeing but developed the degenerative condition retinitis pigmentosa. He was an avid cyclist, but he had to stop riding in 2000. He discovered tandem biking the next year, though, and he has since trained more than 80 riders, sighted and not.

On Tuesday morning, he offered his $1,500 bicycle for a training session on the Upper East Side. Lighthouse International provided a pair of blackout goggles to help simulate the experience of riding without sight. And Mr. Pearlman, a sighted captain on one of the other relay teams, provided the guidance.

Mr. Elefant began with some simple advice: “Make sure your laces are tucked in.”

The stoker — the name comes from stoking an engine to give it power — is the first to mount the bike. When the captain is ready, the challenge is kicking off. The pedals must be in the same position so the cyclists can push together after counting to three.

Communication is key. The captain tells the stoker about every turn, every change in speed. Coordination is especially important when it is time to stop.

“People have forgotten the stoker and gotten off the bike,” Mr. Elefant said. “Guess what happened?”

He laughed as my captain turned to face me.

“I won’t forget you,” Mr. Pearlman said.

This is the first time Lighthouse International, a 105-year-old organization, has put on a bike ride.

“There’s so many walks and runs,” said Mark G. Ackermann, Lighthouse president and chief executive. “This is something very unique and different, and hopefully will give New Yorkers a little bit more respect for people who have this particular disability.”

Blackout goggles by no means equate to Mr. Elefant’s daily experience. The first time I rode wearing them, my eyes closed — a futile, but involuntary, reaction.

“We are passing on the right a very beautiful pre-19th-century building,” Mr. Pearlman said as I got used to riding under his reins. “O.K., and now we’re making a left turn.”

He called out to a man walking two dogs. Their collars jingled.

“Excuse me sir,” he said. “Excuse me.”

On Friday, Mr. Pearlman will ride his four-hour shift with Peter Slatin, a vision-impaired writer. Mr. Elefant, who has the final shift, 6 a.m. to 10 a.m., is paired with a favorite cycling partner, Mark Carhart.

“I call it riding in an automatic car versus a shift,” Mr. Elefant said. “Some people who are in the front are so good when they’re shifting gears it’s like automatic. And then other people, it’s herky-jerky.”

My ride with Mr. Pearlman was brief, not nearly four hours long. The smell of the river is unmistakable. The wind bites. And the sound of passers-by competes with the grinding of the tires.

As we headed south along the river toward 79th Street, the sun appeared. Both of us, seeing or not, felt its warmth.

“We’re going to glide to the end,” Mr. Pearlman said.