A 29-year-old man who viciously attacked a father outside an Auckland bar has been sentenced to two-and-a half years in prison.

Sione Moala appeared at Auckland High Court on Tuesday after being found guilty of wounding with intent to injure and fighting in a public place. He would not be eligible for parole.

The attack happened outside a bar in the central city in April 2016.

Senior Sergeant Mark Clayton said Moala did not know the man when he launched into a cowardly, senseless and unprovoked attack leaving him with serious injuries.

“The victim, a father of a young child, has now lost an eye and his life will never be the same again.

"He has been through a significant amount of trauma, both physical and emotional, as a result of this random, cowardly attack."

Clayton said today's sentencing sent a message that this behaviour and violence in a public place was unacceptable and could cause such immense harm to people and their families and had serious consequences.

He hoped today's outcome would bring some form of comfort and closure to the victim after a long court process.

"We acknowledge and appreciate this has been a difficult time for the victim and his family."