- Unless you're a fly, you can't see 120° around yourself.
I can, though? The human FOV is pretty wide, admittedly with less visual functions on the edges. That's what makes it possible to detect movement and general shapes at almost 180 degrees. A fly's FOV would be closer to the full 360 degrees. Obviously games don't generally go that high...
But to the point: TotalBiscuit made a pretty good video on the subject a while back, using The Darkness 2 as an example: http://www.youtube.com/watch?v=DPDq_qvsKUA.The The game did end getting a patch with FOV options in the end.