Noor Hussain 42, from Amherst Street in Grangetown , jailed for 10 years after he struck taxi driver Ali Begzada, in the face with a metal pole left him blind in one eye.
Ali Begzada had to have surgery but was told by doctors he will never regain the sight in his left eye and can no longer work to support his family.
Mr Begzada was standing by his taxi, talking to a friend outside a kebab shop, when a group of boys arrived on bikes. One boy stayed outside with the bikes while the others went in including Hussain.
Some bikes had gone missing from the home of one of the defendant’s friends and they went out to look for them.
The men confront the boy after they thought the bikes outside the kebab shop were the stolen ones. Mr Begzada saw the child was frightened and intervened.
The court heard Hussain returned to the car they arrived in then grabbed a metal pole and struck the Begzada in the face, blinding him in one eye.
Hussain immediately put the pole back in the car as people began to gather in the busy street. He was arrested and did not answer any questions in his police interview.
Mr Begzada who came from Afghanistan has worked in the UK for nearly 10 years, had surgery in hospital but the consultant concluded there was nothing more they could do to save his vision and the loss of sight is permanent.
Mr Begzada said he is no longer able to work or socialise and described feeling like a prisoner at home.
Hussain was jailed for 10 years and must serve half of that in custody before being released on licence.