Question

Eyes of herbivores are below the forehead an either side of the head​

Answer 1

Quick answer: Because most animals are prey to one thing or another and need To have a wider field of view to better notice predators. While top of the food chain predators are better off with better depth perception to aid them in catching their prey and picking their targets.

Notice the difference between the human and deer? the deer can see nearly all around it, with a small binocular zone, while humans have less peripheral but a larger binocular.

The effects of this are better depth perception and color. (Items at the edges of your vision are colorless, but your brain patches it so you don't notice)

hope it helps !