A man jailed for a "barbaric" knife attack which blinded one of his victims has failed in his bid to have conviction overturned, the Court of Appeal has ruled.
Senior judges dismissed Adam Smyth's challenge against his conviction for the attempted murder of Marc Keller in November 2005.
They also rejected an attempt to reduce the 20-year sentence imposed for the assault Smyth carried out as a 17-year-old with a limited IQ.
Lord Chief Justice Sir Declan Morgan said: "In this case there is absolutely no suggestion that the victims and their friends played any part whatsoever in the events leading up to the gratuitous and barbaric infliction of horrendous violence upon them.
"If a person of full age and intellectual capacity had committed this offence a sentence well in excess of 20 years would have been necessary in order to properly meet the needs of retribution and deterrence for this sort of behaviour."
Smyth, now aged 23 and formerly of Best Hill, Belfast, was also found guilty of wounding Mr Keller's brother Anthony with intent and assault occasioning actual bodily harm.
The victims, from Killyleagh, were attacked by Smyth and two co-accused at a bank machine in Donegall Square North following a night out.
An eight inch knife was plunged into Marc Keller's chest, slicing an artery, and causing optic nerve damage which left him blinded.
He has also suffered permanent bowel damage and restricted mobility as a result of the stabbing.
As part of Smyth's appeal against his conviction for attempted murder his lawyers sought to admit fresh evidence from a former prisoner who claimed a co-accused confessed in jail that he was the one who carried out the knifing.
It was alleged that Newtownards man Philip Irwin (31), who is serving a 12-year-sentence for causing grievous bodily harm with intent to Marc Keller, had bragged to another inmate that he was responsible but Smyth had taken the blame.
But the court refused to admit the hearsay evidence after calling into question its reliability and setting out the difficulties for the prosecution in dealing with it.
A second ground of appeal based on claims that the trial judge misdirected the jury over joint enterprise was also rejected.
Sir Declan said: "The issue for the jury was the intent of the applicant at the time that he wielded this large knife into the chest of the victim up to the hilt."