His iPhone has been set up with special apps that make it easier for him to use.
It's specially set up to listen and talk to him.
It's his lifeline.
Last Friday morning that lifeline vanished.
The former paralympic athlete took a bus to drop off his guide dog, Karson, for some medical tests.
Because he couldn't ride the bus alone, he took a Checker Cab back to the Georgia Tech campus, where he's a grad student in computer science.
Then he panicked.
He'd left his phone in the cab.
Martin called on his friend, Synge Tyson, who is legally blind herself.
With the aid of special glasses and a magnifying glass, she managed to find a signal from Vincent's iPhone on her iPad.
"It would change locations and I said, 'your phone has gotta still be in this taxi because it's a taxi pattern'," she said.
Synge and Vincent said they contacted the cab company, but got no help.
They said they contacted Atlanta Police, but were told since it appeared to be a lost and not a stolen item, they couldn't help.
They also contacted Georgia Tech Campus Police, who they said were sympathetic, but had no jurisdiction.
So after two days they began their own detective work.
Sunday afternoon Vincent's brother drove him around looking for his missing iPhone while friend Synge tracked it on her iPad.
It led them straight to a taxi at the cab driver's home in Clayton County.
"He was flabbergasted," is how Vincent described the cabbie's reaction.
"He didn't even know it was a phone; I really don't think he had any idea what was going on," he added.
Synge was delighted that technology once reserved for the military made the recovery possible.
"An everyday person like myself can help my friend, who's blind, find his phone; I thought it was just wonderful," she said.
Now Vincent Martin has his lifeline again, thanks to his friend Synge, his brother and their persistence.
He also has some advice if you have one.
"Chain your iphone to you; don't take it out of the holster for any reason," he said.
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