Vikings character Ivar the Boneless has deep-blue eyes that turn even bluer when he is in danger, a prominent trait with real-world origins. The television series Vikings, inspired by the sagas of legendary Norse hero Ragnar Lothbrok, debuted in 2013 to praise from fans and critics alike. In later seasons, the series shifted focus to Ragnar’s sons, primarily Björn Ironside and Ivar Ragnarsson. The youngest son of Ragnar and Aslaug, Ivar Ragnarsson is introduced in season 2 and quickly becomes one of the more ruthless characters in the series. Although a continuation of a theme that began with his father, Ivar's blue eyes often have a uniquely distinct glow that adds a layer of realism to the character.
Ivar quickly establishes himself as one of the cruelest characters in the series with a short temper that often manifests itself in brutal murders. Labeled crazy by his own brothers, Ivar’s insatiable lust for war is inhibited only by his physical disabilities. He was born with osteogenesis imperfecta, also known as brittle bone disease, a genetic disorder characterized by fragile bones that easily break (hence the name Ivar the Boneless). Due to this disease, Ivar is crippled and effectively ostracized from society. However, Ivar the Boneless is destined for glory like his father, a destiny symbolized by their piercing blue eyes. More than a common genetic trait of the Scandinavian warriors, blue eyes are a recurring theme in the series. However, there is something very different about Ivar’s eyes.
Ivar the Boneless was a real Viking leader who is said to have suffered from the same disease as depicted in the television series. This influences nearly every aspect of the character, whose uniquely colored eyes add an extra layer of realism. The sclera (white part) of Ivar’s eyes sometimes turns blue, intensifying his natural eye color in a distinct glow. Ivar’s brother, Hvitserk, reveals that when this change occurs, as it does before battle in Vikings season 6, it means Ivar is in great danger of hurting himself. Blue sclera is a symptom of Ivar’s osteogenesis imperfecta, and it’s established that the bluer his eyes, the greater the risk of breaking bones. Ivar used to ask his brothers how blue his eyes were first thing in the morning to determine if it was safe to play that day.
Although Ivar’s physical appearance is more than just a continuation of a theme, there is a parallel drawn between his blue eyes and those of his brother, Ubbe Ragnarsson. Ubbe travels to North America in season 6, where he comes into contact with the indigenous Mi’kmaq people. To the Mi’kmaq, Ubbe’s blue eyes mean danger. It’s never explained exactly why they think this, but it certainly has nothing to do with osteogenesis imperfecta as Ubbe doesn’t suffer from the disease. Ubbe's blue eyes could be a thematic connection to the ambitions of his father, Ragnar, a connection Ivar also shares.
Blue sclera is not a symptom of everyone with osteogenesis imperfecta, but it is a realistic, as well as dramatic, way to depict the genetic bone disorder from which Ivar the Boneless suffers. Vikings establishes that the bluer Ivar’s eyes are, the more danger he’s in of hurting himself. This is played for dramatic effect perhaps most effectively in Vikings season 6, when Ivar’s eyes begin to turn before battle. This would be a clear warning to any rational character seeking to preserve life, but Ivar doesn’t allow anything to come between him and the fame he so desperately desires, not even death.