Two Eyes Two Views

In the picture

1. 1Left eye: receives the tree from a slightly left viewpoint
2. 2Right eye: receives the tree from a slightly right viewpoint
3. 3Tree ahead: sends two slightly offset outlines toward the eyes
4. 4Camera pair: two lenses set the same small distance apart as the eyes

Examples

• Closing one eye, then the other while looking at a pencil held at arm’s length
• Watching a 3D film with special glasses

Quiz: Two Eyes Two Views (Age 12)

1. 1

   Why do two eyes give the brain enough information to judge depth?

   • Because both eyes send exactly the same view, and the brain uses the duplicate.
   • Because each eye gets a slightly different view, and the brain compares the two views.
   • Because the eyes change size slightly to measure how far away things are.
2. 2

   What does the few-centimetre gap between your eyes cause?

   • Each eye receives a slightly different view of what is ahead.
   • Each eye receives the same view but at a different brightness.
   • Each eye can focus on a different object at the same time.
3. 3

   How can a pair of cameras capture the same depth effect as two eyes?

   • By placing both lenses at exactly the same point and direction.
   • By setting two lenses the same small distance apart as the eyes.
   • By using one lens that moves back and forth very quickly.

The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.