To be more convincing as a blind man, Jeff Daniels spent time at the Michigan Commission for the Blind Training Center in Kalamazoo, observing and learning some basic skills used by blind people on a daily basis.
To help him play a brain damaged man, Joseph Gordon-Levitt did not get much sleep and worked out hard at the gym before shooting to help him appear disoriented. He also befriended people with brain damage and read "The Man with a Shattered World: The History of a Brain Wound".
The hockey game Chris listens to on the radio was played during the 2005-2006 NHL season between the Columbus Blue Jackets and the Detroit Red Wings. Players mentioned include Pascal Leclaire, Manny Malhotra, Mark Hartigan, and Trevor Letowski for Columbus and Robert Lang, Mikael Samuelsson, Nicklas Lidstrom, and Tomas Holmstrom for Detroit.