Silo Season 1 didn't answer what "The Syndrome" really is, but an interesting detail surrounding Steven Zahn's new character may have already teased an answer. Based on Hugh Howey's book trilogy of the same name, Apple TV+'s Silo is all set to expand its story and storyline with Season 2,Which is scheduled to premiere on 15 November 2024. Since Silo Season 1 barely covered the first half. In the book, On, Hugh Howe trilogy, season 2 is expected to at least wrap up On's story by the time he finishes his run.

Looks like solo season 2 trailer scene has heterochromia. While his right eye is a bright shade of blue, the left eye is a dull brown. Seeing as how Huey Silo's books don't mention anything specific about Solo's eyes,This is an original detail in the show's storyline. Only time will tell how Solo's heterochromia will tie into the series' broader narrative. However, the fact that the trailer seemingly tries to highlight the detail in its appearance suggests that it will play an important role in the Season 2 storyline.

The eye condition of Solo may be linked to the syndrome.
Syndrome is one of the biggest mysteries of Season 1.

Silo Season 1 reveals the agreement of Silo 18, which stipulates that no citizen affected by "The Syndrome" is allowed to hold public office. The agreement also states that as soon as a resident begins to show symptoms of the syndrome, they must report their condition and vacate their authority in Silo 18. In addition, a signboard in the mechanical of silo 18 also mentions the stages of the syndrome and associated symptoms. the following:

"Involuntary twitching is the first symptom, resulting in skin-to-skin contact, followed by flashes of pain and muscle spasms. Balance and movement are severely impaired. If untreated, So the infection will attack the brain, causing cognitive function to decline and eventually shut down — down to the whole nervous system."

As Silo Season 1 progresses, it also becomes clear that Paul Billings has the syndrome but does not report it because he fears the consequences. Since, like Solo Eye Color Detail, Syndrome is not part of the original Hugh Howe books,Therefore, Solo's eye disorder may have something to do with health conditions. A closer look at Solo's eyes reveals that one reacts less to light than the other. This could mean that Solo has the syndrome as well, and it has significantly affected his overall health and functionality.

The origin of Syndrome in Silo Season 2 may explain what happened to the world.

Whatever end of the world happened would have triggered the spread of the syndrome.

In an interview (via SFX Magazine), Silo's showrunner, Graham Yost, discussed why he introduced the syndrome to the show and what potential story implications it could have. He described the syndrome as "a neurological response to the stress of living in the harsh conditions of the silos." Highlighting that humans were not meant to live the way they do in the series, Yost revealed that he came up with the stipulation after discussing it with Hugh Howe.

Exhibitor revelations suggest that Syndrome may be a mental health condition caused by living in the oppressive environment of a silo. Lack of contact with nature can be another main reason behind this. Or, as many readers of the Silo books will speculate, the syndrome could be linked to the cataclysmic event that caused humans to lock themselves into the titular structure. Hopefully, perhaps through Solo's story, Silo Season 2 will provide more answers.