Alexei, having grown up in what was deemed a city only for the perfect, believed that these people were the only humans alive, a few lessons later, curiousity peaks aND HE WANTS OUT TO SEE WHAT ELSE IS THERE.
He has heterochromia, always has, always will, but he sometimes wears another blue contact to even out the colour, being a little (which is an under exaggeration) insecure about how one is hazel-brown and one is blue,