Sheffield Crown Court was told how on December 22 last year, custody manager at HMP Doncaster, Ivan Thompson, was tasked with arranging for inmate Gary Nicholas to be moved to HMP Lindholme instead.
Prosecuting, Stephanie Hollis, said this came after Nicholas had refused the transfer, when asked by another member of staff.
Ms Hollis said Mr Thompson approached Nicholas, aged 42, as he was stood in the wing with four or five other inmates; and asked him whether he would like to discuss the requested transfer in his cell.
She continued: "The two men turned to go to that cell, and without any provocation the defendant turned and headbutted Mr Thompson.
"It was a blow with such force, Mr Thompson fell backwards to the floor. Whilst he was on his hands and knees, the defendant then forcefully kicked Mr Thompson to the face."
Nicholas, of High Road, Edlington, Doncaster was then pulled off Mr Thompson by another prison guard and was then detained in his prison cell, the court heard.
Mr Thompson, who has worked at the prison for over 20 years, was left with a fractured orbit below his left eye, for which the prison worker was recommended surgery but he declined due to concerns going under the knife may have exacerbated his other health problems.
Since the incident, that court was told that Mr Thompson has changed positions to an office job at the prison, which pays less, due to concerns that another similar injury could result in him losing his sight in his left eye.
In a victim personal statement read out in court, Mr Thompson said the incident had left him feeling 'shocked' because he has always tried to be fair towards prisoners.
Ms Hollis added: "His left eye doesn't close, it's tight and more sunken. He says he feels like people are staring at his eye when they talk to him . He says he didn't really go out much before but doesn't go out at all following this."
The court was told how between October last year and January this year Nicholas punched four inmates in the face in separate, unprovoked attacks. He has since been moved to HMP Durham.
He pleaded guilty to one count of inflicting grievous bodily harm at an earlier hearing.
Nicholas' sentencing was adjourned until August 29, to allow for a pre-sentence report to be prepared.