Basics: What Is Stereopsis?

The two eyes converge on the object of attention.

Dolphins love that humans can view them in 3-D

In Prain Engrish: The ability to view the world with two eyes pointing at the same subject.

Some animals use their two eyes to look at completely different things simultaneously [chameleons]. Some simply look around to get one eye to focus [deer, horses, and cows come to mind]. Predators such as wolves, lions, tigers, and bears [oh my], consistently use both eyes to calculate the distance from their current position to their prey. Humans are awesome, the proverbial freaking bees’ knees, so we have this ability too.