The landlord of The Swan Inn, in Newport, was attacked by Danny McDonald, who was 17 at the time, on the evening of October 26, 2019.
McDonald had been drinking with two friends and other patrons had complained about the levels of noise coming from their table, Shrewsbury Crown Court heard this week.
The group was asked to drink up and leave but the young men took exception and went to the bar to speak to the landlord.
McDonald told the man “I will leave when I want to”, the court heard. They continued talking but rather than leaving McDonald punched the landlord so that he fell and suffered three cracked ribs, said prosecutor Mr Alexander Barbour.
The older man also suffered an injury to his right eye, which resulted in a loss of vision and a need for surgery to reattach the retina.
The court was shown CCTV footage of the violence, in which other drinkers in the pub intervened to try and help the landlord. McDonald, now lives in Monk Sherborne, in Hampshire, was arrested and eventually prosecuted for causing grievous bodily harm without intent.
Mr Charles Crinion, representing the teenager in court, said he had pleaded guilty to the offence at the earliest opportunity and had also experienced family problems at a young age.
Judge Anthony Lowe said McDonald’s behaviour had been “drunken and brutish” and the influence of alcohol was an aggravating factor.
However, he decided there was evidence the defendant could reasonably be rehabilitated and. “with a great degree of reluctance”, imposed a 12-month prison sentence, which was suspended for two years.