Four Polish men have admitted a burglary during which a university lecturer was savagely beaten at his home.
Paul Kohler, 55, was left needing facial reconstruction surgery for a fractured eye socket after he was attacked by a gang of balaclava-clad men.
Mr Kohler's wife, Samantha MacArthur, was also threatened by two of the intruders who tried to tie her to a chair with duct tape.
Pawel Honc, 23, of no fixed abode, and Mariusz Tomaszewski, 32, of Crusoe Road, Mitcham, south London, pleaded guilty at Kingston Crown Court to grievous bodily harm with intent and aggravated burglary.
Two other men, Oskar Pawlowicz, 29, of Pitcairn Road in Mitcham, and Dawid Tychon, 29, of no fixed abode, both admitted aggravated burglary but denied causing grievous bodily harm with intent.
Honc and Tomaszewski were both arrested at the scene, while Tychon and Pawlowicz were tracked down later.
Barristers for the four defendants told Judge Susan Tapping that each wanted to express his "sincere regret and apologies" for the incident.
Mr Kohler, who is head of law at the School of African and Oriental Studies in London, said he was "ecstatic and very pleased" at the men's admissions during the court hearing, during which they were hidden from his view by the dock's frosted glass.
He said: "I would like to meet them face to face, I would like to know why they did it, it is still a big mystery as to why they did it."
Mr Kohler said he had been "great, fine and wonderful" since the attack but was still suffering physically.
He said: "I have continuing trouble with my vision on the left and my wife and children are still quite traumatised by this."
Mr Kohler was attacked on August 11 at his home in Wimbledon, south west London, that he shares with his wife and four daughters.
He opened his door at around 10pm to someone who he believed was one of his daughter's friends, but was instead met by four men who burst in, shouting "Where's the money?"
As he was attacked, he called out to his wife, Ms MacArthur, 50, who was threatened by two men who tried to tape her to a chair, until she managed to wriggle free.
Mr Kohler tried to break loose but found himself confronted by some of the men again almost immediately.
He was knocked to the floor and one of the gang knelt above him holding a heavy wooden cabinet door, demanding to know where the money was or he would hit him with it.
He was only saved when police intervened after his daughter, Eloise, who had locked herself in an upstairs bedroom with her boyfriend, called 999.
Mr Kohler received what were described as "life-changing injuries", including multiple facial injuries and bruising to his body and limbs.
Speaking after today's hearing, he praised the police response as "brilliant".
He said: "They got there in a few minutes and I am sure they saved me from something a lot worse. They couldn't have done more than they have done."
Describing the moment officers saved him from further injury, he added: "They (the gang) were threatening to bring down the door of the wooden cabinet on my head and they were going through miming that process when police arrived."
Mr Kohler said he still does not know why he and his family were targeted, and that he cannot believe that it was linked to the "hobby" bar that he owns in London's Covent Garden.
He said: "I was saying 'There is no money, I am an academic, for God's sake'. That (why they targeted him) is what I want to find out."
He added: "It is very strange. You sit outside and it is as if it happened to someone else - something you never thought you would be part of. Even during it, it felt like that."
The four defendants were remanded in custody until they are sentenced on January 29.
Judge Tapping told them that "only very substantial custodial sentences will be appropriate".