By his side and at the end of his arm is Rugar, his 3-year-old yellow lab; Coughlin's pair of eyes.
"I lost my vision five years ago," says Coughlin. "It happened suddenly and dramatically."
He waited months for Rugar to complete his guide dog training. Then Coughlin had to be trained how to use him.
Now, as CBS News Correspondent Lee Cowan reports, the two are learning something else: Not everyone knows the law.
"This person was literally screaming," says Coughlin, recalling a recent trip to a deli. "He was saying, 'no dogs, no dogs … get the dog out,' and I was saying 'I'm blind.'"
Instead of apologizing, the person told Coughlin "that's some excuse."
It happens, Coughlin says, at least twice a month.
So we followed him with a hidden camera. The same deli still gave him trouble. So did a guard at his neighborhood drug store and a local coffee house.
Most restaurants let him in. One, which turned him away, told Coughlin there were "too many customers in there."
Coughlin tried to explain that he was blind and that Rugar was his guide dog. He also reminded the restaurant host that by law Rugar should be allowed inside.
"I know, no dog," the host replied.
"It would be like denying you your vision," says Penny Reeder, editor of the Brail Forum.
Reeder blames the confusion on the way the law is written.
"It's a little vague," she says.
Under the Americans with Disabilities Act, anyone who serves the public "must allow people with disabilities to bring their service animals into all areas of the facility."
The problem is "service animal" can mean just about anything.
When a 250-pound pig named "Freedom" showed up at an airport two years ago, U.S. Airways allowed the pig to fly.
The reason? Her owner claimed "Freedom" was a service animal, intended to keep her calm while flying.
A stretch? Reeder says it was just the start.
"In California there's a move toward providing dogs to people who have been abused, to make them feel safer," she says.
In fact, there are so many animals that have muddied the waters that the U.S. Justice Department is considering changing the law. One possible option is requiring owners to prove that their animal has been trained or certified.
"We don't want just anybody out there with their Chihuahua claiming to be a guide dog," says Reeder.
Take Cheryle King for example.
Her service animal of choice is a miniature horse. She still gets stares, but both underwent extensive training. That, advocates claim, is the difference.
"She can do it, I just have to learn it," says King.
Just as businesses need to train employees.
"The overall logistics of being blind are frustrating enough without having to deal with mistreatment by shop keepers and store owners," says Coughlin.
Perhaps some don't like dogs, says a restaurant manager.
They'll just have to start.