Eyes
Johannes' eyes are symbolic of his wisdom and his young age. Compared to the older bison Johannes forges a friendship with, whose eyes are failing him, Johannes uses his eyes to guide people through their lives, avoiding danger along the way. This underscores Johannes' genial nature.
The bison
The three bison that occupy that park Johannes often goes to are important symbols of the past. Because of their age, they have experienced countless important things that have shaped not only the park but the people and animals that interact with the park. In many ways, the bison are the "old guard." They house tremendous institutional knowledge, showing the importance of having a reference point to the past.
Light and darkness
Throughout literature, one of the most common symbols is light and darkness. Such symbolism appears in The Eyes and the Impossible, where light is emblematic of good and hope and warmth, and darkness is symbolic of isolation, negativity, and a lack of connection. This shows that everyone, no matter where they come from, needs connection in the world to thrive.
Birds
There is a common motif surrounding birds. Specifically, the recurring imagery of birds in flight, symbolizes freedom and transcendence. The birds represent the desire most beings have for freedom and the ability to rise above more earthly concerns.