Human eyes need a pair of binoculars to see as well as a Pronghorn. The Pronghorn's speed and its remarkable eyesight are adaptations for life on the prairie. It needs to be able to spot predators such as coyotes and wolves as far away as possible. And, since there is no cover for it to hide in, it needs to be able to outrun any predators that manage to sneak within striking range. It can do both easily.
Pronghorns have a strong herd instinct.
This is another adaptation for defense against predators. Dozens of sharp eyes watching make it very difficult for any predator to make a meal of a pronghorn. On the other hand, a herd is easier for a predator to find than a single individual, so confrontations with predators are inevitable. Running away is the final line of defense, and even that is highly refined in pronghorns. The herd runs in perfect unison in a very tight, oval-shaped formation, much like a flock of birds.