Classroom mode

Run it in class

How can one eye miss a patch while the world still looks complete?

Show of hands — before you project anything

Predict a new case: if an outside target starts on one side, which retinal side receives it after the light paths cross?

  • A Way more than you'd guess
  • B About what you'd guess
  • C Way less than you'd guess

Count the votes out loud. Hold them to it — then watch.

Project it (fullscreen)

Discussion prompts

  • Predict a new case: if an outside target starts on one side, which retinal side receives it after the light paths cross?
  • What must be missing at a nerve-cable doorway for light there to make no visual message?
  • How could filling-in help in ordinary life and also occasionally fool you?

Where it shows up in real life

  • Covering one eye while looking through a toy telescope
  • An eye doctor mapping the optic disc and visual field
  • The brain continuing wallpaper texture across missing information

A prediction-first worksheet — no answer key.

zero prep · no login · any projector

Winding down at home? Family mode · Explore every question