How did Zoro from one piece lose his eye?
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.
Does Zoro open his eye?
The running theory is that Zoro never opened his left eye. And he never did it directly. Although, there is a suggestion that Zoro’s eye ended up being opened at the end of the manga chapter 1009, which was published on April 5, 2021, under the title “Naraku”.