4. Creating a model eye
List of supplies:
3 small paper cups
Pin for poking holes in cups
Black marker or black construction paper
a. Cut the bottom out of one of the paper cups and attach the wax paper to it to create a new
bottom. Keep the wax paper as smooth as possible. The wax paper will simulate the retina.
b. Take your second cup and use a pin to poke a small hole in the center of the bottom of the
cup. This hole is the pupil.
c. Place the wax paper cup inside the cup with the small hole in the bottom.
d. Go to a bright window and adjust the spacing between the two cups. You should be able to
see an image on the wax paper, but it will not be quite clear.
e. Take your third paper cup and use a black marker to color the inside, or line it with black
construction paper. This dark lining simulates the choroid. Poke a small hole in the bottom of this
cup (going through the black construction paper as well as the cup, if you’re using construction
paper). Look out the same window as before with this cup on the outside of your wax paper cup.
f. How does the black cup affect image clarity?
g. What does the choroid do to help your eye see more clearly?
h. Now, for one last experiment, make the hole in the bottom cup larger. This simulates the pupil
dilating. What happens to the clarity and brightness of your image?
i. What is the purpose of the pupil dilating in low light and constricting in high light?