Roronoa Zoro — the closed left eye has remained unexplained since the timeskip 

Oda has never officially explained it. Zoro got the scar sometime during his two-year training with Mihawk, and no character in the series has acknowledged it either. The most widely accepted theory is that it happened during training. But fans have built compelling cases for hidden power theories too and Oda is clearly saving this for something.

Before the timeskip, Zoro had both eyes open. He left for two years to train under Dracule Mihawk, the world’s greatest swordsman. When he came back, his left eye was scarred shut. Nobody on the crew said anything. Mihawk never mentioned it. Perona, who was with them the whole time, said nothing either.

That silence is deliberate. Oda does not forget details. If he has not explained the eye after hundreds of chapters and more than a decade of the story, it means he is saving the reveal for a specific moment. Here is everything fans actually know, and every credible theory for what it means.

What We Actually Know

• Before the timeskip: Zoro’s left eye was fully open and uninjured. This is confirmed by every pre-timeskip scene.
• After the timeskip: He returned with a deep scar running across the closed eye. No explanation was given.
• Oda was asked directly: Manga artist Nobuhiro Watsuki (Rurouni Kenshin) saw post-timeskip Zoro and asked Oda about the eye. Oda refused to explain it.
• No character has mentioned it: Not Luffy, not Nami, not Usopp. No one who knew Zoro before the timeskip has reacted to the scar. This is not an accident.
• The eye has opened at least once: In the TV special Heart of Gold, Zoro briefly opens the eye during a serious fight moment. This confirms the eye is not simply gone.

The fact that Oda refused to explain it to another manga artist, while clearly having the answer ready, tells you everything. This is a planned reveal. It has been for years.

The Main Theories

Theory 1: A Training Injury Under Mihawk

This is the most straightforward explanation and the one most fans consider most likely. Zoro trained under the world’s strongest swordsman for two years. Mihawk is not gentle. Zoro is stubborn to the point of self-destruction. A serious injury during that period is not just plausible it is almost expected.

The argument for this theory is simple: it fits Zoro’s character completely. He would not stop training because of a wound. He would train through it, around it, and despite it. The scar becoming permanent is exactly what happens when someone like Zoro refuses to let an injury heal properly.

Theory 2: A Deliberate Self-Imposed Restriction

Some fans believe Zoro is keeping the eye closed intentionally using it as a self-imposed handicap to train harder. Real-world pirates famously wore eyepatches not because they lost an eye, but to keep one eye dark-adapted for below-deck navigation. By fighting with one eye closed, Zoro forces his remaining senses and his Observation Haki to compensate.

His teacher is literally called "Hawk Eyes" Mihawk a man whose defining trait is visual acuity. It would make perfect sense for Mihawk to teach Zoro to fight with reduced vision as a training method, forcing his other senses to sharpen beyond normal limits.

Theory 3: A Hidden Power Sealed Behind the Eye

The more dramatic theory: something lives behind that eye that Zoro either cannot control or chooses not to unleash. Several moments in the series support this. Pre-timeskip, Zoro’s left eye was seen glowing during powerful techniques, including the Demon Asura form in Enies Lobby. After the timeskip, those moments coincide with the eye remaining closed.

The theory connects to Zoro’s cursed swords, his repeated comparisons to a demon within the series, and the Asura technique itself. The idea is that something awakened during the timeskip that Zoro keeps contained through the closed eye. Opening it fully could represent a final transformation moment Oda is holding for a climactic fight.

Theory 4: Conqueror’s Haki Activation

Zoro has been confirmed as a user of Conqueror’s Haki one of the rarest abilities in One Piece, possessed only by those with the qualities of a king. Some fans connect this to the eye. Oda tends to emphasize the eyes of characters when they activate Conqueror’s Haki, and Zoro’s closed eye could represent a sealed-off concentration of that power waiting to be unleashed at the right moment.

Which Theory Is Most Likely?

Honestly, a combination of the first two. The scar itself most likely came from training with Mihawk that is the most grounded explanation and fits the timeline perfectly. Whether Zoro keeps it closed intentionally as a restriction or whether it is simply too damaged to open normally is less clear.

What is almost certain: Oda has a reveal planned. The deliberate silence from every character, the refusal to explain it to Watsuki, and the fact that the eye has been shown to open at least once all of this points to a payoff moment saved for the right fight. Most fans expect it to appear in a battle with Mihawk himself, completing the arc of their relationship.

Zoro’s closed eye is One Piece’s longest-running unresolved mystery. At this point it has outlasted entire arcs and character backstories. When Oda finally reveals it, it will be significant.

If Zoro’s habit of keeping fans guessing intrigues you, his other famous quirk is just as interesting. The full explanation of why Zoro is always sleeping covers the real reasons behind his constant napping and it makes more sense than you might think.

Frequently Asked Questions

Has Oda ever explained Zoro’s eye officially?

No. Oda was asked directly by manga artist Nobuhiro Watsuki and chose not to answer. Within the series, no character has acknowledged the scar. This is deliberate — Oda is holding the explanation for a specific story moment.

Can Zoro still see out of the closed eye?

Most likely yes. In the TV special Heart of Gold, Zoro briefly opens the eye during a serious fight. This suggests the eye functions but Zoro chooses to keep it closed, rather than the eye being completely lost or destroyed.

When did Zoro get the scar?

Sometime during the two-year timeskip, while training under Dracule Mihawk at Mihawk’s castle on Kuraigana Island. His eye was fully open before the timeskip and scarred shut when he returned. Neither Mihawk nor Perona, who were present throughout, have mentioned it.

Why hasn’t any Straw Hat mentioned the scar?

This is the detail that makes the mystery significant. Luffy, Nami, Usopp — people who knew Zoro well before the timeskip — have never reacted to the scar. This is not an oversight. Oda writes every detail intentionally. The most likely explanation is that Oda has told his editors and close collaborators not to address it until the planned reveal.

Will Zoro’s eye ever be revealed?

Almost certainly, yes. With the Final Saga of One Piece now underway and Zoro’s confrontation with Mihawk approaching, most fans expect the eye reveal to happen at or before that fight. For fans who have followed Zoro this closely, the One Piece gymwear collection including Zoro-inspired compression sets and shorts is built for exactly that level of dedication to the character.