how did zoro lose his eye

Roronoa Zoro lost the use of his left eye during the two-year timeskip period of One Piece, which he spent training under Dracule Mihawk, the world's greatest swordsman. The exact circumstances of how Zoro lost his eye have not been explicitly revealed in the manga or anime. However, it is widely believed and theorized that it happened as a result of the intense and grueling training imposed by Mihawk. Zoro returned from the timeskip with a scar across his left eye, which remains permanently closed, suggesting the loss of vision in that eye. The creator of One Piece, Eiichiro Oda, had planned for Zoro to lose his eye from early on in the series, indicating it was a deliberate development rather than an off-screen accident. Some fan theories suggest the closed eye may conceal some hidden power or represent a final form or power-up for Zoro that has yet to be disclosed. Still, so far, it's only confirmed as a scar and a mystery left to be explored in the storyline.