Build your measuring device by gluing the dowel rod to the flat surface of your protractor along the straight side. Glue a small strip of cardboard to the curved side of your protractor directly in the center. You will find the 90 degree mark right at the center.
Cut four different shapes out of your cardboard with your scissors. Make a triangle, a circle, a square and a hexagon. Color each shape a different color with your colored pencils.
Glue each cardboard shape to a different craft stick. Tie a string to each craft stick. Tie the other end of the string to your dowel rod, leaving several feet of string between the two points.
Gather several of your friends with different colored eyes and have them take turns holding the protractor in front of them, with the flat edge closest to their faces.
Take each craft stick one at a time and hold it as far away from your friend as you can. Hold it outside of your friend's field of vision and slowly walk forward until you are directly in front of him. Keep the string taunt as you walk.
Ask each friend to stop you when she can identify the color. Check the protractor to see what degree the string crosses under when she stopped you. Record that number in your notes.
Ask each friend to stop you again when he can identify the shape. Make a note as to what degree the string crossed when you were stopped.
Compile your notes to show when each of your friends could identify the shape and color. Draw conclusions as to which eye color allowed your friend to spot the shapes and colors first.