Alan Thompson, 34, caused the child, who is now aged four, to have breathing difficulties and an epileptic fit.
The little boy has had to undergo an operation for a squint and needs a second operation, Luton Crown Court heard.
His vision was also affected, although that should recover by the time he is aged five or six, the judge was told.
Prosecutor Catherine Milson said: “On December 18, 2015, just before 8am, a 999 call was made to the ambulance service.
“The baby was on a mat on the floor. He was unresponsive and struggling to breathe.”
She added: “He was given oxygen and taken to the ambulance. He was taken to Bedford South Wing Hospital and then transferred to Addenbrooke’s Children’s Unit.”
The baby was examined by doctors who found he had suffered an epileptic seizure and had retinal haemorrhages in both eyes.
“The medical opinion was that it was the result of him being severely shaken – what is known as shaken baby syndrome,” said Ms Milson.
Thompson, of Richbell Court, Bedford, appeared for sentencing, having pleaded guilty to causing grievous bodily harm.
He has a previous conviction for battery from 2008 when he had grabbed a partner by her hair and thrown her to the ground.
Cornelia Dykers, defending, said at the time, Thompson was suffering from depression and was receiving medication.
She said it was an isolated incident and that there will be a resolution without any long-term physical consequences for the child.
Ms Dykers said Thompson had only been charged more than two years after the offence.
Judge Steven Evans told him: “I accept it was loss of control on a single occasion, but the shaking was forcible and significant.
“He was particularly vulnerable. He was just eight months old.”
The judge passed a 20- month prison sentence but suspended it for two years.
Thompson must carry out 200 hours’ unpaid work and 30 days of a rehabilitation activity requirement. He must also pay £600 costs.