How Odin Lost His Eye
4. The Fight That Cost Odin His Eye
Opting to step away from some of the more traditional elements of Norse mythology, the MCU's interpretation of Odin sought to give a different reason for Odin only having one eye.
Rather than the long-established Norse rationale of Odin sacrificing his eye at Mirmir's Well in exchange for 'true wisdom', the 2011 Thor movie revealed Odin's backstory during its first act.
There, audiences saw how this version of Odin had lost his right eye in battle. That particular battle took place in Tønsberg, Norway back in 965 AD, and was part of Asgard's ongoing war against Laufey and the Frost Giants of Jotunheim - with King Odin standing up to stop Laufey from capturing the Nine Realms.
Odin and his Asgardian army would obviously win that battle and the larger war, but Odin lost his right eye in the process. In addition to that loss though, Odin actually gained a son during that battle. That son being Laufey's offspring Loki, who had been left alone to perish.
While the MCU Odin - like the majority of other versions of Odin - was left with just one eye, another iteration of Odin so nearly lost both of his eyes...