A County Down student who "glassed" another young man in a Belfast bar has been jailed for 18 months.
Rory Patrick Flanagan, 23, of Derryboye Road, Crossgar, admitted maliciously wounding David Battisti with a pint glass, but said it was self defence.
A crown court judge said such incidents would not be tolerated.
Mr Battisti sustained two facial wounds and despite four eye operations the court heard there is a strong chance he will lose the sight in one eye.
There is also the possibility the vision in his other eye may be affected in the future.
The incident took place in south Belfast's Botanic Inn on June 17 2006.
Mr Battisti was dancing with his friends as Flanagan was making his way through the crowd on the dancefloor.
A lawyer said the two "accidentally bumped into each other", with both giving a different version of events as to what happened next.
The judge told the court he accepted the defendant was a man of good character, whose remorse was genuine, but spoke of the devastating effect the incident had on the injured party.
Branding glasses as "potentially lethal weapons", the judge said: "In a matter of seconds, the lives of two young men of good character were blighted permanently."