Binocular disparity

Binocular disparity is when your two eyes see slightly different things because they are in slightly different places on your face.

Imagine holding up your two hands in front of your face, one in front of each eye. Your right eye will see more of your right hand, while your left eye will see more of your left hand.

This difference is what allows you to see depth and perceive the 3D world around you. Your brain takes the two slightly different images from each eye and combines them, allowing you to judge how far away objects are from you.

So next time you catch a ball thrown your way, you can thank your binocular disparity (and your brain!) for helping you accurately judge the distance and timing of the catch.