To illuminate how afterimage occurs, create a star, square, or other geometric-shaped light for learners to look at for 30 seconds. Then, have them explain what they see as they shift their focus to a blank wall. A full explanation of how the negative image appears is provided so that you can teach your class about this phenomenon during a unit on light or the eye. 

14 Views 8 Downloads
Additional Tags


  • A fun and vivid demonstration of how sensitive the retina is 
  • A thorough explanation and extension ideas are provided to strengthen your background

  • None