A teenage boy suffered a potentially fractured eye socket when he was attacked and robbed in Uckfield on Sunday December 30.
The boy, who lives locally, was walking in Puddingcake Lane, at around 8pm on Sunday when he was assaulted and cash was stolen from him.
Sussex Police said it is thought that his eye socket was fractured eye and his cheek bone broken.
But his face was initially too swollen to accurately assess the full extent of the injuries and he is due to return to hospital this week for treatment.
Anyone who witnessed the attack or has any information about it is asked to call Sussex Police on 101 quoting serial 875 of 03/01.
Police said two men aged 19 and 20, both from Maresfield, have been arrested on suspicion of GBH and robbery and both have been bailed to return on April 7.