Deep Silver have released the previously promised FOV fix for Metro: Last Light. A custom config tweak will now let you increase the game's field of view from its default setting of 50 vertical degrees. The developers had warned that changing the FOV could "trigger a number of issues," but isn't post-apocalyptic survival all about cobbling together barely functional tools and resources? At the very least, this crude workaround seems in keeping with the setting.
To change the FOV, find the "user.cfg" file in:
LOCALAPPDATA\4A Games\Metro LL\
Locate the line: "r_base_fov X", changing X to your desired value. Just remember, the attribute is the less common vertical FOV. The FOV Calculator will help you out should you need to covert.