Twin sisters from Dublin glassed a man in a bar during an unprovoked attack after they had been drinking all day after a confirmation.
Bernadette and Edel Dowd (25), appeared before Letterkenny Circuit Court in Co Donegal, having pleaded guilty to the assault.
Both women, who are originally from Tallaght, had been out drinking in Ballybofey after the confirmation celebration on May 26, 2017.
Shortly after midnight, a row broke out at Cheers Bar on Main Street.
Innocent bystander Christopher Gallagher, who was out socialising with his parents, was sitting opposite the sisters.
He was initially hit on the forehead by a glass thrown by Edel Dowd.
As he reached up to feel the blood coming down his face, he was then hit on the cheek by another glass, thrown by Bernadette Dowd.
He was taken to Letterkenny University Hospital, where he received stitches in both wounds and was told he would be left with a permanent scar on his cheek.
Both women were later interviewed by gardai and admitted throwing the glasses.
The court was told both women had moved to Ballybofey with their mother and other family members 10 years ago.
The twins, with an address at Donegal Road, Ballybofey, had fallen in with bad company in recent years and had been drinking too much.
Both took to the witness stand and said they were trying to turn their lives around, had not drunk alcohol in nearly a year and were eating healthily and going to the gym.
Edel Dowd's barrister, Fiona Crawford, said her client was easily led, but she was a very decent person when she did not have drink on her.
Dowd told the court: "I'm genuinely sorry to Mr Gallagher and his family. I didn't mean it. It was the drink, and that's the main reason I'm off drink today.
"I shouldn't have acted like that. It was shocking behaviour, it really was. I'm ashamed and really embarrassed by the way I behaved and I always will be."
Bernadette Dowd's barrister, Peter Nolan, said his client and her sister had learned a less-on, and this type of behaviour would not be tolerated and it could lead to incarceration.
Bernadette Dowd told the court: "I'm sorry to Mr Gallagher and everyone in the pub. We had an early day drinking and celebrating a confirmation and it got out of hand.
"We're keeping our heads down, going to the gym and we have turned ourselves around."
Judge John Aylmer said that while both women had previous convictions, they were of a minor nature and this incident was uncharacteristic of them.
He said he put it in the mid-range of such offences, which could result in a sentence of two years in prison, before considering mitigating circumstances.
However, he said he would reduce this to 18 months considering their early guilty plea and genuine remorse.
He added that he wanted to encourage their rehabilitation and suggested a custodial sentence might be counter-productive in their cases.
Instead, he imposed 240 hours of community service in lieu of 18 months in jail and put them under the supervision of the probation service.
He also ordered them to remain off alcohol and not to make contact with anybody with a criminal record, apart from those within their family.