Demonstrating Refraction

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Updated on Feb 05, 2012

Grade Level: 8th -10th; Type: Physics


Glasses and contact lenses refract rays of light so that they are focused on a person’s retina. This science project demonstrates visually how glass can refract light rays.

Research Questions:

  • What do glasses and contact lenses do?
  • How does refraction work?

Did you ever wonder how glasses and contact lenses work? They both actually refract, or bend, light rays. In order to see well, light has to be perfectly focused on a person’s retina. Glasses and contact lenses bend the light so that it will hit the person’s retina correctly.


  • Ruler
  • Pen
  • Shoebox
  • Scissors
  • White paper
  • Glass jar
  • Water
  • Flashlight

Experimental Procedure:

  1. Draw two vertical lines, about an inch apart from each other, in the center of one of the short sides of the shoebox.
  2. Cut along each line from the top to make two slits.
  3. Measure the dimensions of the bottom of the shoebox.
  4. Cut a piece of white paper so that it has exactly the same dimensions, and fit it into the shoebox so that the entire bottom is covered.
  5. Pour water into the glass jar, and place the jar in the center of the white paper.
  6. Turn off the lights in the room.
  7. From the outside of the box, face the flashlight at the two slits in the box’s side.
  8. Turn on the flashlight, and observe how the glass refracts the light that shines through the two slits. This demonstrates how lenses work.

Terms/Concepts: Retina; Refraction; How does the eye work?


  • Experiments With Light, by Salvatore Tocci. Pp 22-24.

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