The anime and the manga have different interpretations of Boruto’s eye. The manga has still left the majority of its information to be explained, but the anime has helped supplement most information.
Boruto’s eye is named the Jougan. It’s exclusive to Boruto and allows him to see chakra paths and travel beyond dimensions. The eye is only known by the Otsutsuki Clan who warn of its immense power and inevitable clash with a preordained destiny.
More information about the eye is revealed later in the series.
Role In The Plot
In the anime, Boruto first thinks his Jougan could be the Byakugan awakening from his Mother’s side. It proved unexplainable for the time being. Boruto only used the Jougan accidentally during times of combat and stress.
Eventually, Boruto and Momoshiki meet. It’s learned the eye has a connection with the Otsutsuki clan, implying Boruto was always meant to meet one of its members to unlock the eye’s full potential.
Momoshiki left a mark on Boruto after their battle. The mark has opened up over time, revealed to hold Momoshiki’s spirit as it attempts to take over Boruto’s body. Momoshiki’s life was on a timer and Boruto proved an appropriate vessel. Boruto could initially keep control of his mark but now suffers from resisting Momoshiki’s influence.
In chapter 53, Boruto’s Jougan activates as Momoshiki takes full control for the first time. The Jougan seemingly flares up over Momoshiki’s presence. The eye signifies Boruto’s connection with the Otsutsuki clan and his inevitable demise as a vessel.
The flash-forward of Boruto facing off against Kawaki shows a level of control over the Jougan. Boruto is in a similar state to when Momoshiki first took over, but the power seems to flow with his own free will.
Other Thoughts on Boruto’s Eye
It wouldn’t be unlikely to see Momoshiki finding some angle to team up with Boruto, especially considering the alien is at odds with the main antagonist faction of the series. Boruto would be a celestial Jinchuriki, a ninja with interstellar power and chakra control.
Only a few characters know about Boruto’s Jougan. Naruto knows about Boruto’s eye as well as Sasuke. In the anime, Boruto told his father about the eye under the impression it may be an awakened Byakugan.
The Jougan’s abilities are a mix of all 3 Dōjutsu eyes. It can transport Boruto through dimensions like the Rinnegan, allow him to sense chakra like the Sharingan and see through obstructions like the Byakugan. The Jougan is likely the strongest than those three eyes.
It’s unfair to say the Jougan is the absolute best since we don’t know the full implications of its role in the main plot. However, it does seem to have abilities that either exceed or match the abilities of other legendary eyes.
The Jougan has been Boruto’s eye forever. Only over the course of the series has it shown to contain abilities reminiscent of the other Dojutsu eyes. It’s implied to connect Boruto to an otherworldly clan.