Why the norm of nature is 2 eyes?(except insects). Why not four, or just one?

Question

From whales to a frog the size of a fingernail, always two eyes.

In: 5

Answer 1

My uneducated guess is that two is enough and three or four eyes do not provide much of an advantage over two eyes. Survival of the fittest, adaptation, … Is simply who can reproduce the most before their death.