Wong Kin-keung pleaded guilty to throwing corrosive fluid with intent to do grievous bodily harm.
The High Court heard that just a day before the assault in November 2020, Wong was given a suspended jail sentence for attacking the same 63-year-old man with a hammer.
Passing sentence, judge Audrey Campbell-Moffat said Wong’s “vicious” acid attack had caused unbearable and permanent harm to his victim.
She noted that the defendant had poured three bottles of a high concentration acidic liquid into a urinal pot so he could splash as much as possible onto his victim, saying the intent was to cause maximum pain.
Campbell-Moffat also said she didn’t believe the defendant had shown any remorse and appeared to have been happy to see that his neighbour was suffering.
The judge said she had knocked some time off the prison term due to Wong’s guilty plea, but one month was added because he broke the law again during the earlier suspended sentence period.