The Enigmatic Secret of Zoro's Eye in One Piece

One Piece, a legendary manga and anime series, has always been a treasure trove of mysteries leaving fans eager to unravel the secrets behind them. Among these numerous mysteries, one that has captivated the audience for years is the secret behind Roronoa Zoro's closed left eye. Ever since he returned from the two-year timeskip, Zoro has been sporting a scar over his left eye, leaving fans wondering about its origin and significance. In this comprehensive article, we will explore some of the most popular and intriguing theories surrounding the enigma of Zoro's eye.
 

The Timeskip Transformation

When Zoro returned from the timeskip, fans were surprised to see that the formidable Straw Hat swordsman was now missing an eye. The absence of any explanation only fueled the curiosity and speculation regarding the cause of this mysterious injury. Many believe that it might be the result of rigorous training Zoro underwent under the tutelage of Mihawk, the world's strongest swordsman. 

Oda's Master Plan

In an interview with the creator of Rurouni Kenshin, One Piece creator Eiichiro Oda revealed that he had planned for Zoro to become a one-eyed swordsman from the very inception of the series. However, Oda remained tight-lipped about the reason for Zoro's eye injury, only further piquing the interest of fans. 

The Eye of the Conqueror

One popular theory among fans is that Zoro possesses the Conqueror's Haki power, which he can activate through his left eye. Although Conqueror's Haki seems to emanate from a person's entire body and aura, Oda has often emphasized the eyes of the user when this Haki is activated. This theory postulates that Zoro's left eye is integral to the activation of his Conqueror's Haki. 

Captain-like Behavior

Supporters of this theory argue that Zoro has displayed several traits consistent with Conqueror's Haki users. In the pre-timeskip One Piece, Zoro often acted like a captain and was even mistaken for the Straw Hats' captain on multiple occasions. Moreover, during the Punk Hazard arc, fans speculate that Zoro used Conqueror's Haki against Monet, causing her to suddenly stop in her tracks. 

Precedent for Multiple Haki Users

The idea of multiple members of a crew possessing Conqueror's Haki is not unheard of in the One Piece universe. For example, both Big Mom and Katakuri have this power, and they were once part of the same crew – the Rocks Pirates – along with Kaido, who also possesses Conqueror's Haki. 

Controlling Asura's Powers

Another fascinating theory suggests that Zoro's closed left eye is a means to control his Asura powers. Proponents of this theory believe that Zoro is "possessed" by the Asura demon as a result of using cursed swords throughout the series. Although Zoro has demonstrated his Asura form post-timeskip without opening his eye, this theory still holds water as his left eye has glowed on several occasions throughout the series, most notably during the Water 7 saga. 

Mihawk's Influence

Fans of this theory argue that Mihawk, Zoro's mentor, might have instructed him to close his eye to not rely on the demon's power. Mihawk is known to set high standards for Zoro and would likely want him to surpass Mihawk's own abilities using his strength, not Asura's. 

The Principle of Ocular Dominance

While less flashy than other theories, the concept of ocular dominance is perhaps the most plausible explanation for Zoro's closed left eye. Ocular dominance is a medical phenomenon where one eye is used more often, has better vision, or can fixate on something more effectively than the other eye. In a profession like swordsmanship, having 20/20 vision or equally performing eyes is undoubtedly beneficial. 

Mihawk's Hawk Eyes

Considering Mihawk's epithet "Hawk Eye," it is reasonable to assume that the world's greatest swordsman is an expert on vision. It is entirely possible that Mihawk noticed Zoro's ocular dominance in his left eye during their duel and training and scarred the left eye shut, instructing Zoro not to open it until his right eye was adequately trained. This theory is further supported by Zoro's poor sense of direction and occasional misreading of signs, such as in Sabaody.