Monovision
This is the first I've heard of bifocal contacts so obviously I haven't tried them, but I've been using monovision contacts for a few years.
One side is for distance, the other side for close. The eye to be used for sighting needs to be corrected according to the type of sight, which can be a little tricky especially if you are shooting a pistol with irons and a rifle with optics in the same match.
Snapshot