A US man who had his throat deliberately and inexplicably slashed by a barber during shaving expressed concern at the idea his attacker might offend again once he leaves jail in ten years' time.

Timothy Vaughn, a 33-year-old petty officer with the US Navy was having his hair cut in San Diego last year, when the coiffeur Daniel Roberto Flores, 22, took a razor blade to his throat and slit it open twice.

Flores pleaded guilty to attempted murder and was given (June 11) the maximum sentence of 10 years in jail.

After the sentencing, Vaughn, who survived thanks to his medical training, said he was worried the barber could commit the same crime once out.

"It's very unsettling knowing he's going to be back with society one day," Vaughn was quoted as saying by Fox5. "There was no reason why this happened... he's gonna get out and it could happen again".

Handing down the sentence, Judge Garry Haehnle Flores said the fact there was no apparent motive behind Flores's action meant he was a "great danger to society", Reuters reported.

Vaughn and Flores didn't know each before the Navy officer walked into Vic's Barber Shop in Imperial Beach, south of the Californian city.

Authorities said there was no argument between the two as the barber attended to the sailor's hair.

Deputy District Attorney Laura Evans said Flores suddenly asked to trim his client's beard. "He said: 'I could cut your throat', and then he did," Evans told the court, according to the news agency.

Flores fled the crime scene on his bike but was later arrested. Vaughn said he is still facing the consequences of the attack. "I relive it every hour, every day, with nightmares when I try to sleep," he said, Reuters reported.