Neon

Georgi was having trouble seeing.

Vacuumers operate in shifts of 16 hours on, 4 hours off for five days in a row, with three days of downtime. During their breaks, most of Georgi's colleagues stayed in the seedier sections of the city, near the exteriors.

For the majority of vacuumers, it was enough to dabble in illegal, though lightly-monitored, activities such as drug use or gene manipulation. Only the most foolhardy went in for neon ingestion. Georgi, however, wasn't worried about harm to his nervous system.

But if he couldn't see, he'd be fired and sent back to the vents.

Part Two