How are we so good at getting around in our environment? How can we play basketball or other sports? How can we tell that two objects at different distances are actually at different distances? As humans, we have really excellent depth perception; this skill actually develops early in childhood. Proper visual experience during this “critical period” in childhood is actually very important for this skill. In this lesson plan we’ll learn how important input from both eyes is for depth perception. We’ll also learn what the biological underpinning of depth perception and how this develops in the brain. This lesson plan is designed for a middle school audience but can be made into a high school lesson plan (supplemental material provided).