activity page will offer:
into the eye's anatomy
chance to model red-eye reflection
critical examination of red-eye elimination
In this activity, you'll create a model of an eyeball. By examining
the structure of this body part, you'll create an understanding
of why red-eye occurs. You'll even explore the angles of incoming
light that may reduce this annoying byproduct of flash photography.
mache paste (non-toxic paste obtained from art teacher)
TEACHER NOTE: Scissors are sharp. Caution the students when using
these tools. Review proper classroom behavior and techniques when
using paper mache.
- Blow up a round balloon so that it is about 5 inches (about
12.5 cm) in diameter.
- Use scissors to carefully cut pieces of scrap newspaper into
- Put on gloves and safety goggles. Soak the strips in paper mache
paste. Review safety concerns associated with this step.
- Cover the balloons with two layers of soaked paper mache strips.
Let dry. Then, add two more layers of soaked strips. Wait one
- Have your instructor poke a small hole into the dried paper
mache covering. Remove the balloon through this hole.
- When the balloon is removed, have your instructor insert scissors
into the hole and cut the dried paper mache cast in half, forming
two hollow hemispheres.
- Then have the instructor use scissors to carefully cut out a
coin-sized circular hole in the center of one hemisphere.
- Wearing both gloves and eye protectors, paint the inside of
the both hemispheres red.
- When the paint has dried, use tape to secure these halves back
into a complete sphere.
- Aim the beam of a flashlight directly into the opening. What
do you see?
- Aim the beam at different angles into the eye. How does the
angle of the light affect the observed red eye artifact. Which
angles produce less red-eye reflection?
- Why was the inside of the eyeball model painted red?
- What does the coin-sized opening represent?
- How did the angle of the incident flashlight beam affect the
red-eye property of the model?
Why does the angle of incident light affect the appearance of red-eye?
One strategy for reducing red-eye uses a burst of flashes that occur
just before the actual image is captured. Why would a burst of bright
flashes reduce red-eye? Think about it and then present your ideas
to the class. You may wish to share your understanding using your
paper mache model.
Suppose you were in charge of marketing a red-eye reduction device
that could be attached to any camera. How would you market this
tool? How much of the science would you share with your audience?
With access to computer graphics software, create a magazine ad
that addresses the benefits and simplicity of your invention. If
resources are available, script and shoot an "infomercial" that
markets this device to the general public.
Red-Eye Flash Photography
The physics of anti-red-eye photography as presented by a Mechanical
of the Eye
An introduction to eye anatomy that includes a QuickTime journey
into the eye.
A primer on the science, history and application of waterjet cutting.