Luffy met Rayleigh where as Zoro met Mihawk . So to upgrade the fighting skills Mihawk trained Zoro. Since Mihawk have hawkeye , so after the training Mihawk gifted is eye to Zoro as a reward . So Zoro have cut on one of his eye.
From episode 487. Jinbe was carrying luffy after he lost conscience after ace died and Akainu attacked Jinbe. He pierced right through Jinbe’s chest and hit luffy. When they show luffy again he as the X shaped scar on his chest.