Answer:
First of all where gloves when handling him, that way you don't infect each other with germs. Next inspect his eye, if he lets you and see where the injury is. If it looks like something that can be fixed with a bandage, then you can tend to it with soft, clean, sentless towels. Try disinfecting the wounded area, and if possible, use a nontoxic non harmful cleaner. (Meaning nothing that can hurt the bird). If you don't have anything "fancy", to clean the wound, then using clean water should be fine. Don't forget to feed him, watch him, and give him water. It shouldn't take too long for the wound to heal up, but it wouldn't hurt keeping an eye on him, and check his progress routinely.
Explanation:
This is a bit long, but hope it helps :)
And I hope he recovers soon.